Switching method, communication device, chip and chip module

Abstract

Disclosed are a switching method, a communication device, a chip and a chip module, the method comprising: receiving a layer 2 signaling, the layer 2 signaling comprising a conditional switching command, the conditional switching command indicating conditional switching; and if a target cell meeting the conditional switching triggering condition exists in the at least one first candidate cell subjected to conditional switching, initiating switching to the target cell. The terminal equipment is indicated to perform condition switching through the layer 2 signaling, so that the target cell suitable for the terminal equipment can be determined, and the switching performance can be improved.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a handover method, a communication device, a chip, and a chip module. Background Art

[0002] The propagation of wireless signals and the mobility of users cause the wireless signals around the terminal device to change dynamically, which may lead to a decline or even interruption of the service quality provided by the network device for the terminal device. To ensure the continuity and quality of the service, the terminal device can switch to other cells.

[0003] Currently, the network device can select a target cell for the terminal device from the candidate cells and instruct the terminal device to switch to the target cell. However, the target cell indicated by the network device may not be suitable for the terminal device, which will affect the handover performance. Summary of the Invention

[0004] This application discloses a handover method, a communication device, a chip, and a chip module. By using layer 2 signaling to instruct the terminal device to perform conditional handover, it is beneficial to determine a target cell suitable for the terminal device, thereby improving the handover performance.

[0005] In a first aspect, an embodiment of this application provides a handover method, where the method includes: receiving layer 2 signaling, where the layer 2 signaling includes a conditional handover command, and the conditional handover command indicates to perform conditional handover; if there is a target cell that meets the conditional handover trigger condition among at least one first candidate cell for conditional handover, initiate a handover to the target cell.

[0006] In this technical solution, by using layer 2 signaling to instruct the terminal device to perform conditional handover, on the one hand, it is beneficial to determine a target cell suitable for the terminal device, thereby improving the handover performance. On the other hand, the terminal device can independently determine the time of conditional handover, which can avoid premature handover or late handover. For example, it can perform a handover in a timely manner when the channel condition deteriorates, thereby further improving the handover performance.

[0007] In a possible implementation manner, the conditional handover command further indicates to perform conditional handover based on the layer 1 measurement results of the foregoing at least one first candidate cell, and that the target cell meets the conditional handover trigger condition includes: the layer 1 measurement results of the target cell meet the conditional handover trigger condition of the target cell.

[0008] In a possible implementation manner, the conditional handover command includes information about the foregoing at least one first candidate cell. The information about the at least one first candidate cell may include information such as the identifier and index of the at least one first candidate cell.

[0009] In a possible implementation, the method further includes: receiving first indication information; wherein, the first indication information is used to indicate the foregoing at least one first candidate cell; or, the first indication information is used to indicate at least one second candidate cell, and the at least one second candidate cell includes the foregoing at least one first candidate cell.

[0010] In this technical solution, the first indication information may be carried in an RRC signaling, and the conditional handover command may be carried in a MAC-CE. The first indication information in the RRC signaling is used to indicate at least one first candidate cell, and the conditional handover command is used to indicate a conditional LTM handover. In this case, the candidate cells indicated by the first indication information in the RRC signaling are the at least one first candidate cells for the conditional handover, and the conditional handover command in the MAC-CE may not need to indicate the at least one first candidate cell. In this way, the signaling overhead of the MAC-CE can be saved.

[0011] In a possible implementation, the number of the foregoing at least one first candidate cells is N1, the number of the foregoing at least one second candidate cells is N2, the conditional handover command is carried by at least a first bit field, the first bit field includes N2 bit positions, and one bit position among the N2 bit positions corresponds to one second candidate cell among the N2 second candidate cells; wherein, among the N2 bit positions, the values of the N1 bit positions corresponding to the N1 first candidate cells are a first value.

[0012] In this technical solution, by setting the values of the bit positions corresponding to the at least one first candidate cells in the bitmap of the conditional handover command to the first value to indicate the at least one first candidate cell, it is beneficial to efficiently indicate the at least one first candidate cell.

[0013] In a possible implementation, the method further includes: sending layer 1 measurement results of the foregoing at least one second candidate cell.

[0014] In a possible implementation, the conditional handover command further indicates one or more of the following: the conditional handover trigger condition of the foregoing at least one first candidate cell, the timing advance information of the foregoing at least one first candidate cell, the preamble of the foregoing at least one first candidate cell, the downlink TCI state of the foregoing at least one first candidate cell, the uplink TCI state of the foregoing at least one first candidate cell, the downlink BWP of the foregoing at least one first candidate cell, the uplink BWP of the foregoing at least one first candidate cell, the first SSB metric, the first CSI-RS metric;

[0015] Among them, the layer 1 measurement results of the at least one first candidate cell include the measurement results of at least one SSB metric and / or the measurement results of at least one CSI-RS metric. The at least one SSB metric includes a first SSB metric, and the at least one CSI-RS metric includes a first CSI-RS metric. The layer 1 measurement results of the target cell satisfying the conditional handover trigger condition of the target cell include: the measurement results of the first SSB metric and / or the first CSI-RS metric of the target cell satisfying the conditional handover trigger condition of the target cell.

[0016] In a possible implementation, the conditional handover trigger conditions of the at least one first candidate cell include one or more of the following: signal quality trigger condition, distance trigger condition, time trigger condition; the layer 1 measurement results of the target cell satisfying the conditional handover trigger condition of the target cell include one or more of the following: the layer 1 measurement results of the signal quality of the target cell satisfying the signal quality trigger condition of the target cell, the distance of the terminal device from the reference position of the target cell satisfying the distance trigger condition of the target cell, the first moment satisfying the time trigger condition of the target cell, where the first moment is the moment when the layer 1 measurement results of the signal quality of the target cell satisfy the signal quality trigger condition of the target cell.

[0017] In a possible implementation, the moment when it is determined that the target cell satisfies the conditional handover trigger condition is earlier than the moment when it is determined to initiate the first handover to the first cell; and / or, the priority of the handover to the target cell is higher than the priority of the first handover; where the first handover and the conditional handover have different handover types, and the candidate cell set of the first handover includes the first cell.

[0018] In a possible implementation, the method further includes: if the moment when it is determined that the target cell satisfies the conditional handover trigger condition is later than the moment when it is determined to initiate the first handover to the first cell, and / or, the priority of the handover to the target cell is lower than the priority of the first handover, initiate the first handover to the first cell; where the first handover and the conditional handover have different handover types, and the candidate cell set of the first handover includes the first cell.

[0019] In this technical solution, the terminal device can perform handover more timely, which is beneficial to improving handover performance.

[0020] In a possible implementation, the layer 2 signaling is MAC-CE.

[0021] In a second aspect, an embodiment of the present application provides another handover method, the method includes: sending layer 2 signaling, the layer 2 signaling includes a conditional handover command, and the conditional handover command instructs to perform a conditional handover.

[0022] In this technical solution, the terminal device is instructed to perform conditional handover through layer 2 signaling, which is beneficial to improving the handover performance.

[0023] In a possible implementation, the conditional handover command is further used to instruct conditional handover based on the layer 1 measurement results of at least one first candidate cell.

[0024] In a possible implementation, the conditional handover command includes information of the at least one first candidate cell. The information of the at least one first candidate cell may include information such as the identifier and index of the at least one first candidate cell.

[0025] In a possible implementation, the method further includes: sending first indication information; wherein, the first indication information is used to indicate the at least one first candidate cell; or, the first indication information is used to indicate at least one second candidate cell, and the at least one second candidate cell includes the at least one first candidate cell.

[0026] In this technical solution, the first indication information may be carried in RRC signaling, and the conditional handover command may be carried in MAC-CE. The first indication information in the RRC signaling is used to indicate at least one first candidate cell, and the conditional handover command is used to indicate conditional LTM handover. In this case, the candidate cells indicated by the first indication information in the RRC signaling are the at least one first candidate cells for conditional handover, and the conditional handover command in the MAC-CE may not need to indicate the at least one first candidate cell. In this way, the signaling overhead of the MAC-CE can be saved.

[0027] In a possible implementation, the number of the at least one first candidate cell is N1, the number of the at least one second candidate cell is N2, the conditional handover command is carried by at least a first bit field, the first bit field includes N2 bit positions, and one bit position among the N2 bit positions corresponds to one second candidate cell among the N2 second candidate cells; wherein, among the N2 bit positions, the N1 bit positions corresponding to the N1 first candidate cells take a first value.

[0028] In this technical solution, by setting the values of the bit positions corresponding to the at least one first candidate cell in the bitmap of the conditional handover command to the first value to indicate the at least one first candidate cell, it is beneficial to efficiently indicate the at least one first candidate cell.

[0029] In a possible implementation, the method further includes: receiving the layer 1 measurement results of the at least one second candidate cell; and determining the at least one first candidate cell from the at least one second candidate cell based on the layer 1 measurement results of the at least one second candidate cell.

[0030] In a possible implementation, the conditional handover command is further used to indicate one or more of the following: the conditional handover triggering condition of the at least one first candidate cell, the timing advance information of the at least one first candidate cell, the preamble of the at least one first candidate cell, the downlink TCI state of the at least one first candidate cell, the uplink TCI state of the at least one first candidate cell, the downlink BWP of the at least one first candidate cell, the uplink BWP of the at least one first candidate cell, a first SSB metric, a first CSI-RS metric; wherein, the layer 1 measurement result of the at least one first candidate cell includes the measurement result of at least one SSB metric and / or the measurement result of at least one CSI-RS metric, the at least one SSB metric includes the first SSB metric, and the at least one CSI-RS metric includes the first CSI-RS metric.

[0031] In a possible implementation, the conditional handover triggering condition of the at least one first candidate cell includes one or more of the following: a signal quality triggering condition, a distance triggering condition, a time triggering condition.

[0032] In a possible implementation, the layer 2 signaling is MAC-CE.

[0033] In a third aspect, an embodiment of the present application provides a communication device, and the device includes a unit for implementing the method described in the first aspect or the second aspect.

[0034] In a fourth aspect, an embodiment of the present application provides another communication device, including a processor; the processor is configured to execute the method described in the first aspect or the second aspect.

[0035] In an optional implementation, the communication device may further include a memory; the memory is used to store a computer program; the processor is specifically configured to call the computer program from the memory and execute the method described in the first aspect or the second aspect.

[0036] In a fifth aspect, an embodiment of the present application provides a chip, and the chip is used to execute the method described in the first aspect or the second aspect.

[0037] In a sixth aspect, an embodiment of the present application provides a chip module, and the chip module includes a communication interface and a chip, where: the communication interface is used for internal communication of the chip module or for communication between the chip module and an external device; the chip is used to execute the method described in the first aspect or the second aspect.

[0038] In a seventh aspect, an embodiment of the present application provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, the computer program includes program instructions, and when the program instructions are executed by a communication device, the communication device is caused to execute the method described in the first aspect or the second aspect.

[0039] In an eighth aspect, an embodiment of the present application provides a computer program product including a computer program or instructions. When the computer program or instructions run on a computer, the computer is caused to execute the method described in the first aspect or the second aspect.

[0040] The present application discloses a handover method, a communication device, a chip, and a chip module. By using layer 2 signaling to instruct a terminal device to perform conditional handover, it is beneficial to determine a target cell suitable for the terminal device, thereby facilitating the improvement of handover performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a flowchart of CHO;

[0042] Figure 2 is a flowchart of LTM;

[0043] Figure 3 A schematic diagram of the architecture of a communication system applicable to an embodiment of the present application;

[0044] Figure 4 is a flowchart of a handover method provided by an embodiment of the present application;

[0045] Figure 5 is a flowchart of another handover method provided by an embodiment of the present application;

[0046] Figure 6 is a schematic diagram of the structure of a communication device provided by an embodiment of the present application;

[0047] Figure 7 is a schematic diagram of the structure of another communication device provided by an embodiment of the present application;

[0048] Figure 8 is a schematic diagram of the structure of yet another communication device provided by an embodiment of the present application;

[0049] Figure 9 is a schematic diagram of the structure of a chip module provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] It should be understood that the terms "first", "second", etc. involved in the embodiments of the present application are used to distinguish different objects, rather than to describe a specific order. The "at least one" in the embodiments of the present application refers to one or more, and the plurality refers to two or more. The "and / or" in the embodiments of the present application describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. Among them, A and B can be singular or plural. The character " / " can represent an "or" relationship between the preceding and following associated objects. In addition, the symbol " / " can also represent a division sign, that is, perform a division operation.

[0051] The "at least one (item)" or its similar expression in the embodiments of the present application refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c can represent the following seven situations: a, b, c, a and b, a and c, b and c, a, b, and c. Among them, each of a, b, and c can be an element or a set containing one or more elements.

[0052] First, some concepts or technologies involved in the embodiments of the present application are introduced.

[0053] 1. Terminal device

[0054] In the embodiments of the present application, the terminal device is a device with wireless transceiver functions and supporting communication through at least two connections, which can be called a terminal, user equipment (UE), mobile station (MS), mobile terminal (MT), access terminal device, Internet of Things terminal device, vehicle-mounted terminal device, industrial control terminal device, UE unit, UE station, mobile station, remote station, remote terminal device, mobile device, UE terminal device, wireless communication device, UE agent, or UE device, etc. The terminal device can be fixed or mobile. It should be noted that the terminal device can support at least one wireless communication technology, such as long term evolution (LTE), NR, 6th-generation (6G) mobile communication system, or next-generation wireless communication technology, etc.

[0055] For example, the terminal device may be a mobile phone, a tablet (pad), a desktop computer, a laptop computer, an all-in-one computer, a vehicle-mounted terminal, a virtual reality (VR) terminal device, an augmented reality (AR) terminal 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, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing devices connected to a wireless modem, a wearable device, a terminal device in a future mobile communication network, or a terminal device in a future evolved public land mobile network (PLMN), etc. In some embodiments of the present application, the terminal device may also be a device with transceiver functions, such as a chip module. Among them, the chip module may include a chip and may also include other discrete devices. Embodiments of the present application do not limit the specific technologies and specific device forms adopted by the terminal device.

[0056] 2. Network device

[0057] In the embodiments of the present application, the network device is a device that provides wireless communication functions for terminal devices. The network device may be an access network (AN) device, a satellite, and the AN device may be a radio access network (RAN) device. Among them, the network device may support at least one wireless communication technology, such as LTE, NR, 6G, etc.

[0058] Exemplarily, the network device includes, but is not limited to: the next-generation base station (generation nodeB, gNB) in the fifth-generation mobile communication system (5th-generation, 5G), evolved node B (eNB), radio network controller (RNC), node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved node B, or home node B, HNB), baseband unit (BBU), transmission and reception point (TRP), transmitting point (TP), mobile switching center, etc. The network device can also be a radio controller, a centralized unit (CU) and / or a distributed unit (DU) in the cloud radio access network (CRAN) scenario, or the network device can be a relay station, an access point, a vehicle-mounted device, a wearable device, and an access network device in future mobile communications or an access network device in a future-evolved PLMN, etc. In some embodiments, the network device can also be a device with the function of providing wireless communication for the terminal device, such as a chip module. Exemplarily, the chip module can include a chip and can also include other discrete devices. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the network device.

[0059] 3. Conditional handover (CHO)

[0060] The general idea of CHO is that the network device sends the CHO configuration to the terminal device. After receiving the CHO configuration, the terminal device does not immediately initiate a handover to the target cell like the traditional handover mechanism. Instead, it first saves the CHO configuration until the signal of the target cell meets the handover conditions in the CHO configuration, and then initiates a handover to the target cell.

[0061] Figure 1 For the process schematic diagram of CHO, as Figure 1 shown, the process of CHO can include, but is not limited to, the following steps. In the embodiments of the present application, S represents step.

[0062] S101: The source network device sends an RRC reconfiguration message to the terminal device. The RRC reconfiguration message includes parameters such as measurement objects, reporting configurations, and measurement identities. Correspondingly, the terminal device receives the Radio Resource Control (RRC) reconfiguration message.

[0063] The source network device may be the base station to which the serving cell of the terminal device belongs.

[0064] Among them, the measurement objects may indicate the carrier frequency, time position, and subcarrier spacing of the reference signal to be measured.

[0065] The reporting configurations may include: reporting criteria and reference signal type reporting formats. Among them, the reporting criteria: the criteria for triggering the terminal device to send a measurement report, and the reporting criteria can be divided into measurement event triggering and periodic reporting. The reporting type: synchronization signal / physical broadcast channel block (SSB) or channel state information reference signal (CSI-RS). The reporting format: the number of each cell and / or each beam included in the measurement report by the terminal device, and other relevant information, such as the maximum number of cells to be reported and the maximum number of beams for each cell.

[0066] Measurement identities (MeasID): In the 5G network, each cell has a measurement identity list, and in each measurement identity, a measurement object is associated with a reporting configuration. By configuring multiple MeasIDs, more than one measurement object can be linked to the same reporting configuration, or more than one reporting configuration can be linked to the same measurement object.

[0067] S102: The terminal device measures candidate cell 1 and candidate cell 2 according to the RRC reconfiguration message, obtains the measurement reports of candidate cell 1 and candidate cell 2, and sends the measurement reports to the source network device. Correspondingly, the source network device receives the measurement reports.

[0068] The terminal device can measure at least one candidate cell according to the RRC reconfiguration message to obtain a measurement report. Figure 1 Here, an example is given where the number of at least one candidate cell is 2, and the two candidate cells are candidate cell 1 and candidate cell 2 respectively.

[0069] It can be understood that if the criterion for triggering the terminal device to send a measurement report is measurement event triggering, then the measurement report sent by the terminal device to the source network device in S102 may include: the measurement event that triggers the terminal device to send the measurement report.

[0070] The measurement performed by the terminal device in S102 may be a layer 3 measurement. Correspondingly, after the terminal device performs a layer 3 measurement, a layer 3 measurement report is obtained.

[0071] In the embodiments of the present application, layer 1 (L1) may include the Physical Layer (PHY). Layer 2 (L2) may include the Medium Access Control (MAC) layer, the Radio Link Control (RLC), and the Packet Data Convergence Protocol (PDCP) layer. Layer 3 (L3) may include the Radio Resource Control (RRC) layer.

[0072] S103: The source network device decides to use conditional handover and sends a CHO request message 1 to candidate network device 1 that meets the handover conditions according to the measurement report. Correspondingly, candidate network device 1 receives the CHO request message 1.

[0073] Candidate network device 1 is the base station to which candidate cell 1 belongs, and candidate network device 2 is the base station to which candidate cell 2 belongs.

[0074] S104: Candidate network device 1 performs access control. If it agrees to the conditional handover, it sends a CHO request confirmation message 1 to the source network device. Correspondingly, the source network device receives the CHO request confirmation message 1.

[0075] Among them, when candidate network device 1 performs access control, it can determine whether to agree (or permit) the conditional handover. Candidate network device 1's agreement to the conditional handover may mean that candidate network device 1 allows the terminal device to access candidate cell 1, or candidate network device 1 allows the terminal device to use conditional handover to access candidate cell 1.

[0076] S105: The source network device decides to use conditional handover and sends a CHO request message 2 to candidate network device 2 that meets the handover conditions according to the measurement report. Correspondingly, candidate network device 2 receives the CHO request message 2.

[0077] S106: Candidate network device 2 performs access control. If it agrees to the conditional handover, it sends a CHO request confirmation message 2 to the source network device. Correspondingly, the source network device receives the CHO request confirmation message 2.

[0078] Among them, the candidate network device 2 performs access control and can determine whether to approve (or allow) conditional handover. The candidate network device 2's approval of conditional handover can mean that the candidate network device 2 allows the terminal device to access the candidate cell 2, or the candidate network device 2 allows the terminal device to use conditional handover to access the candidate cell 2.

[0079] S107: The source network device sends the CHO configuration to the terminal device. Correspondingly, the terminal device receives the CHO configuration.

[0080] The CHO configuration may include configuration information of at least one candidate cell and triggering conditions for conditional handover corresponding to each candidate cell. Taking the at least one candidate cell including candidate cell 1 and candidate cell 2 as an example, the CHO configuration may include configuration information of candidate cell 1, configuration information of candidate cell 2, and triggering conditions for conditional handover corresponding to candidate cell 1 and triggering conditions for conditional handover corresponding to candidate cell 2.

[0081] Among them, the configuration information of the candidate cell may include some information of the candidate cell and some resources configured by the network device for the terminal device in the candidate cell. For example, the Cell Global Identifier (CGI) or Physical Cell Identifier (PCI) of the candidate cell, and the protocol layer configuration information configured by the network device for the terminal device in the candidate cell. The protocol layer configured by the network device for the terminal device in the candidate cell may include, but is not limited to, the physical layer (PHY), media access control layer (MAC), radio link control (RLC), packet data convergence protocol (PDCP), etc.

[0082] After receiving the CHO configuration, the terminal device can evaluate whether candidate cell 1 meets the triggering condition corresponding to candidate cell 1 in the CHO configuration, evaluate whether candidate cell 2 meets the triggering condition corresponding to candidate cell 2 in the CHO configuration, and use the candidate cell that meets the triggering condition as the target cell. Figure 1 Taking candidate cell 1 meeting the triggering condition as an example for illustration.

[0083] The CHO configuration may be carried in the RRC reconfiguration message. The triggering condition in the CHO configuration may also be referred to as the execution condition.

[0084] S108: The terminal device performs random access with the target cell, and the target cell is candidate cell 1.

[0085] After the terminal device determines the target cell, the terminal device performs random access with the target cell. After the random access is successfully completed, the terminal device may send an RRC reconfiguration complete message to the network device to which the target cell belongs.

[0086] Random access refers to the process in which the terminal device sends a preamble to the network device, establishes a radio link with the network device, and obtains or restores uplink synchronization. Random access is a key step in a mobile communication system, enabling the terminal device and the network device to establish a communication connection. The terminal device performs information interaction with the network device through random access and can also achieve uplink synchronization through random access.

[0087] In S108, the way for the terminal device to access the target cell can be non-competitive random access.

[0088] In one implementation, the random access performed by the terminal device with the target cell can be triggered by a Physical Downlink Control Channel order (PDCCH order). When the PDCCH order indicates the preamble index (Preamble Index) and the physical random access channel Mask Index (PRACH Mask Index) that the terminal device should use, this PDCCH order is used to trigger the terminal device to perform non-competitive random access. When the preamble index in the PDCCH order is all 0, it is an invalid preamble index. In this case, this PDCCH order is used to trigger the terminal device to perform competitive random access. It can be understood that when the PDCCH order is used to trigger the terminal device to perform non-competitive random access, the preamble index in this PDCCH order is a valid index, that is, the preamble index is not all 0. Among them, the PRACH mask index is used to determine the PRACH resource location for the non-competitive random access process.

[0089] S109: The terminal device sends an RRC reconfiguration complete message to candidate network device 1. This RRC reconfiguration complete message is used to notify candidate network device 1 that the conditional handover is completed.

[0090] After the random access is successfully completed, the terminal device may send an RRC reconfiguration complete message to candidate network device 1.

[0091] 4. Layer 1 / Layer 2 Triggered Mobility (L1 / 2Trigger mobility, LTM)

[0092] Based on the method of triggering service cell change through layer 3 measurement and RRC signaling, the terminal device needs to perform a complete connection reconfiguration process to fully switch to the target cell, which brings a relatively long interruption time and signaling overhead during the whole process. Based on this, LTM is introduced. The core idea of LTM is to use L1 / L2 signaling to change the serving cell, which can achieve low latency, low overhead, and low data interruption time.

[0093] Figure 2 FIG. is a schematic diagram of the LTM process, as Figure 2 shown, the LTM process may include but is not limited to the following steps.

[0094] S201: The terminal device sends a measurement report to the source network device. Correspondingly, the source network device receives the measurement report.

[0095] Among them, the source network device is the base station to which the serving cell of the terminal device belongs.

[0096] The measurement report sent by the terminal device in S201 may be a layer 3 measurement report, which is obtained by the terminal device after performing layer 3 measurement.

[0097] S202: The source network device sends an RRC reconfiguration message to the terminal device. The RRC reconfiguration message includes the configuration information of the LTM candidate cell. Correspondingly, the terminal device receives the RRC reconfiguration message.

[0098] The RRC reconfiguration message may include the configuration information of at least one LTM candidate cell. Figure 2 In this example, the number of at least one LTM candidate cell is 2, and the two LTM candidate cells are LTM candidate cell 1 and LTM candidate cell 2 respectively for illustration.

[0099] Taking LTM candidate cell 1 as an example, the configuration information of LTM candidate cell 1 may include the identifier of LTM candidate cell 1, the PCI of LTM candidate cell 1, the SSB configuration of LTM candidate cell 1, the pre-synchronization configuration of LTM candidate cell 1, the transmission configuration indication (TCI) status list of LTM candidate cell 1, etc.

[0100] S203: The terminal device sends an RRC Connection Reconfiguration Complete message to the source network device. Correspondingly, the source network device receives the RRC Connection Reconfiguration Complete message.

[0101] The RRC Connection Reconfiguration Complete message may indicate that the terminal device has completed the reconfiguration.

[0102] S204a: The terminal device performs downlink synchronization with LTM candidate cell 1 and LTM candidate cell 2.

[0103] S204b: The terminal device performs uplink synchronization with LTM candidate cell 1 and LTM candidate cell 2.

[0104] Figure 2 The candidate network device 1 in [ ] can be the base station to which LTM candidate cell 1 belongs, and the candidate network device 2 can be the base station to which LTM candidate cell 2 belongs.

[0105] S205: The terminal device sends a layer 1 measurement report to the source network device. Correspondingly, the source network device receives the layer 1 measurement report.

[0106] The terminal device performs downlink synchronization and uplink synchronization with LTM candidate cell 1, and performs layer 1 measurement on LTM candidate cell 1 to obtain the layer 1 measurement result of LTM candidate cell 1. Similarly, the terminal device performs downlink synchronization and uplink synchronization with LTM candidate cell 2, and performs layer 1 measurement on LTM candidate cell 2 to obtain the layer 1 measurement result of LTM candidate cell 2.

[0107] The layer 1 measurement report sent by the terminal device to the source network device may include the layer 1 measurement result of LTM candidate cell 1 and the layer 1 measurement result of LTM candidate cell 2.

[0108] S206: The source network device sends a cell handover command to the terminal device, and the cell handover command instructs the terminal device to hand over to LTM candidate cell 1. Correspondingly, the terminal device receives the cell handover command.

[0109] After receiving the layer 1 measurement report, the source network device can determine the target cell from LTM candidate cell 1 and LTM candidate cell 2 according to the layer 1 measurement results of LTM candidate cell 1 and LTM candidate cell 2, and then instruct the terminal device to hand over to the target cell. Figure 2 Taking the target cell as LTM candidate cell 1 as an example for illustration.

[0110] S207: The terminal device performs random access with LTM candidate cell 1.

[0111] The way for the terminal device to access LTM candidate cell 1 can be non-competitive random access, or the random access performed by the terminal device with LTM candidate cell 1 can be triggered by a Physical Downlink Control Channel order (PDCCH order).

[0112] S208: LTM is completed.

[0113] After the successful completion of random access, the terminal device may indicate the completion of LTM to the LTM candidate network device 1.

[0114] The LTM process may be divided into: an LTM preparation stage, an LTM execution stage, and an LTM completion stage. Among them, the LTM preparation stage may include S201 to S203, the LTM execution stage may include S205 to S207, and the LTM completion stage may include S208.

[0115] The above is a simple introduction to some concepts or technologies involved in the embodiments of the present application.

[0116] The embodiments of the present application provide a handover method. By using layer 2 signaling to instruct the terminal device to perform conditional handover, it is beneficial to determine a target cell suitable for the terminal device, thereby facilitating the improvement of handover performance.

[0117] Please refer to Figure 3 , Figure 3 which is a schematic diagram of the architecture of a communication system applicable to the embodiments of the present application. The communication system may include, but is not limited to, a terminal device, a source network device, and at least one candidate network device. The source network device may include a network device (such as a base station) to which the serving cell of the terminal device belongs, and the at least one candidate network device may include a network device to which at least one candidate cell configured for the terminal device belongs. The embodiments of the present application take the example that two candidate cells are configured for the terminal device, and the two candidate cells are candidate cell 1 and candidate cell 2 respectively for illustration. Figure 3 The dashed line in indicates the network coverage range of the corresponding cell. For example, the dashed line corresponding to the source network device may indicate the network coverage range of the serving cell.

[0118] Figure 3 In, the candidate network device 1 is the network device to which candidate cell 1 belongs, and the candidate network device 2 is the network device to which candidate cell 2 belongs. It should be noted that the network devices to which different candidate cells belong may be the same or different. For example, the candidate network device 1 and the candidate network device 2 may be the same network device, that is, the network device to which candidate cell 1 belongs is the same as the network device to which candidate cell 2 belongs. Or, the candidate network device 1 and the candidate network device 2 may be different network devices, that is, the network device to which candidate cell 1 belongs is different from the network device to which candidate cell 2 belongs.

[0119] Figure 3 The number and form of the devices shown are for illustration and do not constitute a limitation on the embodiments of the present application. In practical applications, there may be more terminal devices and more candidate network devices.

[0120] It should be noted that the technical solutions of the embodiments of the present application can be applied to various communication systems. For example: 5G mobile communication systems, 5G NR systems. Optionally, the methods of the embodiments of the present application are also applicable to various future communication systems, such as 6G systems or other communication networks, etc.

[0121] It can be understood that the communication systems described in the embodiments of the present application are for more clearly explaining the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art know that with the evolution of the system architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0122] The handover method proposed in the embodiments of the present application will be described below. This handover method can be executed by a terminal device and a network device, or by a device matching the terminal device (such as a chip, a chip module, or a processor, etc., a device placed inside the terminal device) and a device matching the network device (such as a chip, a chip module, or a processor, etc., a device placed inside the network device).

[0123] Please refer to Figure 4 , Figure 4 which is a schematic flowchart of a handover method provided by the embodiments of the present application. As Figure 4 shown, the handover method may include but is not limited to the following steps.

[0124] S401: The source network device sends layer 2 signaling, and the layer 2 signaling includes a conditional handover command. Correspondingly, the terminal device receives the layer 2 signaling, and the conditional handover command indicates to perform a conditional handover.

[0125] The source network device may be the Figure 3 source network device in.

[0126] In the embodiments of the present application, layer 2 (layer 2, L2) may include a media access control (medium access control, MAC) layer, a radio link control (Radio Link Control, RLC), and a packet data convergence protocol (Packet Data Convergence Protocol, PDCP) layer. Among them, the layer 2 signaling may be signaling processed by this protocol layer of layer 2. Exemplarily, the layer 2 signaling may include a MAC-control element (control element, CE).

[0127] The conditional handover command may be used to instruct the terminal device to perform a conditional handover, that is, the terminal device can be triggered to perform a conditional handover through the conditional handover command in the layer 2 signaling. Compared with through RRC signaling (such as Figure 1The method of triggering the terminal device to perform conditional handover by carrying the CHO configuration in S107 in the RRC reconfiguration message can achieve lower latency, lower overhead, and lower data interruption time through layer 2 signaling. Since RRC signaling belongs to layer 3 signaling, when triggering the terminal device to perform conditional handover through layer 3 signaling, the terminal device needs to execute a complete connection reconfiguration process to fully switch to the target cell, which will bring a relatively large interruption time and signaling overhead.

[0128] S402: If there is a target cell that meets the conditional handover trigger condition among at least one first candidate cell for conditional handover, the terminal device initiates a handover to the target cell.

[0129] After receiving the layer 2 signaling, in response to the conditional handover command in the layer 2 signaling, the terminal device evaluates whether there is a target cell that meets the conditional handover trigger condition among at least one first candidate cell for conditional handover. If so, the terminal device initiates a handover to the target cell. It can be understood that the terminal device determines the target cell from the at least one first candidate cell based on the conditional handover trigger condition. On the one hand, it is beneficial to determine a target cell suitable for the terminal device, thereby improving the handover performance. On the other hand, the terminal device can independently determine the time of conditional handover, which can avoid premature handover or late handover. For example, a handover can be performed in a timely manner when the channel condition deteriorates, which is beneficial to further improving the handover performance.

[0130] The at least one first candidate cell includes the target cell. In this embodiment of the application, taking the number of at least one first candidate cell as 2, the two first candidate cells are candidate cell 1 and candidate cell 2 respectively, and the target cell is candidate cell 1 as an example. Among them, the network device to which candidate cell 1 belongs can be Figure 3 the candidate network device 1 in Figure 3 and the network device to which candidate cell 2 belongs can be

[0131] Optionally, the at least one first candidate cell may include Figure 2 some or all of the at least one LTM candidate cell (LTM candidate cell) mentioned in S202 in

[0132] Among them, the at least one first candidate cell and / or the conditional handover trigger condition can be configured for the terminal device by the source network device through high-layer signaling. For example, the source network device sends high-layer signaling to the terminal device, and the high-layer signaling is used to indicate the at least one first candidate cell and / or the conditional handover trigger condition. The high-layer signaling can be RRC signaling. For example, Figure 1The CHO configuration in S107 shown above may include the condition handover trigger condition. This CHO configuration may be carried in the RRC reconfiguration message. In this case, the terminal device may, based on this CHO configuration, evaluate whether there is a target cell among the at least one first candidate cell that meets the condition handover trigger condition.

[0133] Alternatively, the at least one first candidate cell and / or the condition handover trigger condition may be indicated by a conditional handover command. For example, the conditional handover command may include information on the at least one first candidate cell and / or the condition handover trigger condition. The information on the at least one first candidate cell may include information such as the identifier and index of the at least one first candidate cell.

[0134] The specific implementation for the terminal device to initiate a handover to the target cell may be: the terminal device releases the connection with the original serving cell and establishes a connection with the target cell, and then monitors the PDCCH or PDSCH of the target cell and optionally performs random access.

[0135] After the terminal device successfully accesses the target cell, the terminal device may send uplink data or CSI report to the network device to which the target cell belongs. The uplink data or CSI report may be used to notify the network device to which the target cell belongs that the conditional handover is completed.

[0136] In a possible implementation, if there is no cell among the at least one first candidate cell for the conditional handover that meets the condition handover trigger condition, the terminal device may not perform the handover. That there is no cell among the at least one first candidate cell that meets the condition handover trigger condition means that each first candidate cell does not meet the condition handover trigger condition.

[0137] In the embodiments of the present application, the terminal device is instructed to perform conditional handover through layer 2 signaling. On the one hand, it is beneficial to determine a target cell suitable for the terminal device, thereby facilitating the improvement of handover performance. On the other hand, the terminal device can independently decide the time of conditional handover, which can avoid premature handover or late handover. For example, a handover can be performed in a timely manner when the channel condition deteriorates, which is further beneficial to improving handover performance.

[0138] Optionally, if the moment when the terminal device determines that the target cell meets the condition handover trigger condition is earlier than the moment when the terminal device determines to initiate a first handover to the first cell; and / or the priority of the handover initiated by the terminal device to the target cell is higher than the priority of the first handover, the terminal device may initiate a handover to the target cell. Among them, the first handover and the conditional handover have different handover types, and the candidate cell set of the first handover includes the first cell.

[0139] Optionally, if the time when the terminal device determines that the target cell meets the condition handover trigger condition is later than the time when the terminal device determines to initiate a first handover to the first cell, and / or the priority of the handover initiated by the terminal device to the target cell is lower than the priority of the first handover, the terminal device may initiate the first handover to the first cell. In this way, the terminal device can perform handover more timely, which is beneficial to improving handover performance.

[0140] In one implementation, the conditional handover commanded by the network device for the terminal device may be an LTM conditional handover, and the LTM conditional handover is different from the Figure 1 conditional handover shown. The terminal device evaluates whether there is a target cell that meets the condition handover trigger condition among at least one first candidate cell for the conditional handover based on layer 1 measurement results, while Figure 1 in [reference document], the terminal device evaluates whether at least one candidate cell in the CHO configuration meets the trigger condition in the CHO configuration based on layer 3 measurement results.

[0141] It can be understood that the handover types of the first handover and the LTM conditional handover are different. Optionally, the first handover may include but is not limited to a layer 3 handover, Figure 1 the conditional handover shown, Figure 2 the LTM handover shown. The LTM conditional handover may also be described as a conditional LTM handover, a conditional LTM handover, or a conditional LTM handover.

[0142] The layer 3 handover, Figure 1 the conditional handover shown, Figure 2 the LTM handover shown, and the LTM conditional handover proposed in the embodiments of the present application may each configure their own candidate cell sets. Among them, the candidate cell set configured for the LTM conditional handover includes the aforementioned at least one first candidate cell. If the first handover is Figure 2 the LTM handover shown, then the first cell is a subset of the candidate cell set configured for the LTM handover (i.e., Figure 2 the at least one LTM candidate cell (LTM candidate cell) mentioned in S202 in [reference document]). If the first handover is Figure 1 the conditional handover shown, then the first cell is a subset of the candidate cell set configured for the conditional handover (i.e., Figure 1 the at least one candidate cell included in the CHO configuration mentioned in S107 in [reference document]). If the first handover is a layer 3 handover, then the first cell is a subset of the candidate cell set configured for the layer 3 handover, and the layer 3 handover may configure the candidate cell set for the terminal device through RRC signaling.

[0143] The time when the terminal device determines that the target cell meets the condition handover trigger condition may be the time when the terminal device evaluates that the target cell meets the condition handover trigger condition. The first handover isFigure 2 In the case of the LTM handover shown, the moment to initiate the first handover to the first cell can be Figure 2 the moment when the terminal device receives the cell handover command in S206 shown. In this case, the cell handover command instructs the terminal device to hand over to the first cell. The first handover is Figure 1 In the case of the conditional handover shown, the moment to initiate the first handover to the first cell can be Figure 1 the moment when the terminal device evaluates that the first cell meets the triggering condition for conditional handover in the corresponding content. When the first handover is a layer 3 handover, the moment to initiate the first handover to the first cell can be the moment when the terminal device evaluates that the first cell meets the handover condition for layer 3 handover.

[0144] That is to say, the terminal device supports multiple handover types. For example, the handover types supported by the terminal device include LTM conditional handover and the first handover. When the terminal device determines that the target cell meets the triggering condition for conditional handover based on the handover mechanism corresponding to the LTM conditional handover, and the terminal device determines that the first cell meets the handover condition for the first handover based on the handover mechanism corresponding to the first handover, the terminal device can determine which type of handover to trigger preferentially based on the priority of the moment and / or the handover type.

[0145] In one implementation, when the moment when the terminal device determines that the target cell meets the triggering condition for conditional handover (hereinafter referred to as moment a) is the same as the moment to initiate the first handover to the first cell (hereinafter referred to as moment b), the source network device can instruct the terminal device to preferentially initiate a handover to the target cell.

[0146] Or, when moment a is the same as moment b, the source network device can instruct the terminal device to preferentially initiate a handover to the first cell.

[0147] Or, when moment a is the same as moment b, the protocol can stipulate that the terminal device preferentially initiates a handover to the target cell.

[0148] Or, when moment a is the same as moment b, the protocol can stipulate that the terminal device preferentially initiates a handover to the first cell.

[0149] Or, when moment a is the same as moment b, the terminal device can decide by itself whether to preferentially initiate a handover to the target cell or to the first cell.

[0150] Please refer to Figure 5 , Figure 5 which is a schematic flowchart of another handover method provided by the embodiments of this application. As Figure 5 shown, the handover method can include but is not limited to the following steps.

[0151] S501: The source network device sends layer 2 signaling, and correspondingly, the terminal device receives the layer 2 signaling. The layer 2 signaling includes a conditional handover command, and the conditional handover command indicates a conditional handover based on layer 1 measurement results of at least one first candidate cell. That is, the conditional handover command indicates the layer 1 measurement results of at least one first candidate cell for the conditional handover.

[0152] The layer 1 measurement results of one first candidate cell may include, but are not limited to, one or more of the following: the layer 1 reference signal received power (L1-RSRP) of the first candidate cell, the layer 1 reference signal received quality (L1-RSRQ) of the first candidate cell, and the layer 1 signal-to-noise and interference ratio (L1-SINR) of the first candidate cell.

[0153] The reference signal may include, but is not limited to: a synchronization signal / physical broadcast channel block (SSB), a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), or other reference signals. The embodiments of the present application do not limit the type of the reference signal.

[0154] Optionally, the layer 1 measurement results of the at least one first candidate cell may be measured by the terminal device.

[0155] It should be noted that for other content of S501, reference may be made to Figure 4 the specific description of S401 in the corresponding embodiment, which will not be elaborated here.

[0156] S502: If there is a target cell that meets the conditional handover trigger condition among the at least one first candidate cells for the conditional handover, the terminal device initiates a handover to the target cell. The target cell meeting the conditional handover trigger condition includes: the layer 1 measurement results of the target cell meet the conditional handover trigger condition of the target cell.

[0157] In a possible implementation, the condition handover trigger conditions for the at least one first candidate cell may include one or more of the following: signal quality trigger condition, distance trigger condition, time trigger condition. Among them, the layer 1 measurement result of the target cell satisfying the condition handover trigger condition of the target cell may include one or more of the following:

[0158] 1. The layer 1 measurement result of the signal quality of the target cell satisfies the signal quality trigger condition of the target cell. Taking the layer 1 measurement result of the signal quality of the target cell including L1-RSRP and the signal quality trigger condition of the target cell including the first power as an example, if the L1-RSRP of the target cell is higher than the first power, then the layer 1 measurement result of the signal quality of the target cell satisfies the signal quality trigger condition of the target cell. Optionally, if the L1-RSRP of the target cell is lower than or equal to the first power, then the layer 1 measurement result of the signal quality of the target cell does not satisfy the signal quality trigger condition of the target cell.

[0159] 2. The distance between the terminal device and the reference position of the target cell satisfies the distance trigger condition of the target cell. Taking the distance trigger condition of the target cell including the first distance as an example, if the distance between the terminal device and the reference position of the target cell is less than the first distance, then the distance between the terminal device and the reference position of the target cell satisfies the distance trigger condition of the target cell. Or, if the distance between the terminal device and the reference position of the serving cell is greater than the second distance and the distance between the terminal device and the reference position of the target cell is less than the first distance, then the distance between the terminal device and the reference position of the target cell satisfies the distance trigger condition of the target cell. Optionally, if the distance between the terminal device and the reference position of the target cell is greater than or equal to the first distance, then the distance between the terminal device and the reference position of the target cell does not satisfy the distance trigger condition of the target cell. Or, if the distance between the terminal device and the reference position of the serving cell is less than or equal to the second distance, or the distance between the terminal device and the reference position of the target cell is greater than or equal to the first distance, then the distance between the terminal device and the reference position of the target cell does not satisfy the distance trigger condition of the target cell. Among them, the distance between the terminal device and the reference position of the serving cell, and the distance between the terminal device and the reference position of the target cell can be obtained by technologies such as positioning reference signals. Optionally, the second distance may be greater than or equal to the first distance.

[0160] 3. The first moment satisfies the time trigger condition of the target cell, where the first moment is the moment when the layer 1 measurement result of the signal quality of the target cell satisfies the signal quality trigger condition of the target cell. Taking the time trigger condition including a time period [t1, t2], the layer 1 measurement result of the signal quality of the target cell including L1-RSRP, and the signal quality trigger condition of the target cell including a first power as an example, if the L1-RSRP of the target cell measured by the terminal device at the first moment is higher than the first power, and the first moment is within the time period [t1, t2], then the time trigger condition of the target cell is satisfied.

[0161] Optionally, when the first moment satisfies the time trigger condition of the target cell, the terminal device may initiate a handover to the target cell within the time period [t1, t2].

[0162] Among them, the first power, the first distance, the second distance, and the time period [t1, t2] may be indicated by high-layer signaling; or, the first power, the first distance, the second distance, and the time period [t1, t2] may be indicated by a conditional handover command; or, the first power, the first distance, the second distance, and the time period [t1, t2] may be agreed upon by the protocol. The embodiments of the present application do not make any limitations in this regard.

[0163] Optionally, the source network device may select the time period [t1, t2] from multiple time periods configured by RRC signaling and indicate the time period [t1, t2] to the terminal device. Among them, the RRC signaling may be Figure 2 the RRC reconfiguration message in S202 shown.

[0164] Optionally, the conditional handover trigger condition in S502 may be a conditional handover trigger condition for layer 1. After receiving the conditional handover command, the terminal device may evaluate whether the layer 1 measurement results of the at least one first candidate cell satisfy the layer 1 conditional handover trigger condition. If the layer 1 measurement result of the target cell satisfies the layer 1 conditional handover trigger condition of the target cell, the terminal device initiates a handover to the target cell.

[0165] Among them, the layer 1 conditional handover trigger condition may be carried in Figure 1 the CHO configuration in S107 shown. In this case, after receiving the layer 2 signaling, the terminal device evaluates whether the layer 1 measurement results of the at least one first candidate cell satisfy the layer 1 conditional handover trigger condition based on the CHO configuration, and then determines the target cell.

[0166] Optionally, the conditional handover trigger conditions for different first candidate cells may be the same or different. Taking the number of at least one first candidate cell as 2, and the two first candidate cells being candidate cell 1 and candidate cell 2 respectively, the conditional handover trigger condition of candidate cell 1 and the conditional handover trigger condition of candidate cell 2 may be partially the same, completely the same, or completely different.

[0167] Optionally, the conditional handover trigger condition for one first candidate cell is for the serving cell and the first candidate cell. Taking the number of at least one first candidate cell as 2, and the two first candidate cells being candidate cell 1 and candidate cell 2 respectively, if the conditional handover trigger condition of candidate cell 1 includes a signal quality trigger condition #1, the signal quality trigger condition #1 may be that the signal quality of candidate cell 1 is better than that of the serving cell, and the conditional handover trigger condition of candidate cell 2 includes a signal quality trigger condition #2, the signal quality trigger condition #2 may be that the signal quality of candidate cell 2 is better than that of serving cell 1. When the terminal device meets the signal quality trigger condition #1, it switches from the serving cell to candidate cell 1, and the signal quality trigger condition #2 is no longer applicable to the situation where the terminal device switches from candidate cell 1 to candidate cell 2, which may easily lead to handover failure.

[0168] It can be understood that for the terminal device, after receiving the layer 2 signaling, it can evaluate whether the layer 1 measurement results of each first candidate cell meet the conditional handover trigger conditions of the corresponding first candidate cell. For example, taking the number of at least one first candidate cell as 2, and the two first candidate cells being candidate cell 1 and candidate cell 2 respectively, the terminal device needs to evaluate whether the layer 1 measurement results of candidate cell 1 meet the conditional handover trigger conditions of candidate cell 1, and also needs to evaluate whether the layer 1 measurement results of candidate cell 2 meet the conditional handover trigger conditions of candidate cell 2.

[0169] It should be noted that for other content of S502, reference can be made to Figure 4 the specific description of S402 in the corresponding embodiment, which will not be elaborated here.

[0170] In the embodiments of the present application, by using the layer 2 signaling to instruct the terminal device to perform conditional handover, on the one hand, it is beneficial to determine the target cell suitable for the terminal device, thereby improving the handover performance. On the other hand, the terminal device can independently determine the time of conditional handover, which can avoid premature handover or late handover. For example, it can perform handover in a timely manner when the channel condition deteriorates, which is further beneficial to improving the handover performance.

[0171] Optionally, before S501, the handover method may further include S500a. S500a is an optional step, that is, the source network device may not execute S500a. Figure 5The steps indicated by the dashed lines are optional steps.

[0172] S500a: The source network device sends first indication information, where the first indication information is used to indicate at least one first candidate cell; or, the first indication information is used to indicate at least one second candidate cell, and the at least one second candidate cell includes at least one first candidate cell. Correspondingly, the terminal device receives the first indication information.

[0173] Among them, the first indication information may be carried in the RRC signaling.

[0174] In the first implementation manner, the first indication information in the RRC signaling is used to indicate at least one first candidate cell, and the conditional handover command in S501 (e.g., carried in the MAC-CE) is used to indicate a conditional LTM handover. In this case, the candidate cells indicated by the first indication information in the RRC signaling are the at least one first candidate cells for the aforementioned conditional handover, and the conditional handover command in the MAC-CE may not need to indicate the at least one first candidate cell. In this way, the signaling overhead of the MAC-CE can be saved.

[0175] In the second implementation manner, the first indication information in the RRC signaling is used to indicate at least one second candidate cell, and the conditional handover command in S501 (e.g., carried in the MAC-CE) is used to indicate at least one first candidate cell. In this case, the at least one first candidate cell may be a subset determined by the source network device from the at least one second candidate cell. That is to say, the set of candidate cells indicated by the MAC-CE may be a subset of the set of candidate cells indicated by the RRC signaling.

[0176] Optionally, the at least one second candidate cell may include Figure 2 the at least one LTM candidate cell mentioned in S202, and the at least one first candidate cell may be a subset of the at least one LTM candidate cell.

[0177] Optionally, before S501, the handover method may further include S500b. S500b is an optional step, that is, the terminal device may not execute S500b.

[0178] S500b: The terminal device sends the layer 1 measurement results of the at least one second candidate cell. Correspondingly, the source network device receives the layer 1 measurement results of the at least one second candidate cell.

[0179] After the terminal device measures the layer 1 measurement results of the at least one second candidate cell, it may send the layer 1 measurement results of the at least one second candidate cell to the source network device.

[0180] Optionally, after receiving the layer 1 measurement results of the at least one second candidate cell, the source network device may select the at least one first candidate cell from the at least one second candidate cell based on the layer 1 measurement results of the at least one second candidate cell. Alternatively, after receiving the layer 1 measurement results of the at least one second candidate cell, the source network device may decide to use LTM conditional handover, and then select the at least one first candidate cell from the at least one second candidate cell based on the layer 1 measurement results of the at least one second candidate cell.

[0181] Optionally, the number of the at least one first candidate cell is N1, the number of the at least one second candidate cell is N2, and the conditional handover command is carried by at least a first bit field. The first bit field includes N2 bit positions, and one bit position in the N2 bit positions corresponds to one second candidate cell among the N2 second candidate cells; wherein, among the N2 bit positions, the values of the N1 bit positions corresponding to the N1 first candidate cells are a first value.

[0182] For example, taking the first bit field including 3 bit positions (i.e., N2 = 3), the 3 second candidate cells being candidate cell 1, candidate cell 2, and candidate cell 3 respectively, and the first bit position, the second bit position, and the third bit position in the 3 bit positions corresponding to candidate cell 1, candidate cell 2, and candidate cell 3 in sequence, and the first value being 1 as an example. If the values of the first bit position and the second bit position in the 3 bit positions are both 1, and the value of the third bit position is 0, then the terminal device may determine that the number of the at least one first candidate cell is 2, and the 2 first candidate cells are candidate cell 1 and candidate cell 2 respectively. In this way, it can be understood that the source network device indicates the at least one first candidate cell by setting the values of the bit positions corresponding to the at least one first candidate cell in the bitmap of the conditional handover command to 1. In this way, it is beneficial to efficiently indicate the at least one first candidate cell.

[0183] Wherein, both N1 and N2 are positive integers, and N2 is greater than or equal to N1. In other feasible implementation manners, the first value may also be other values other than 1, such as the first value being 0.

[0184] Optionally, the conditional handover command may further indicate one or more of the following: the conditional handover triggering condition of the foregoing at least one first candidate cell, the timing advance information of the foregoing at least one first candidate cell, the preamble of the foregoing at least one first candidate cell, the transmission configuration indication (TCI) state of the foregoing at least one first candidate cell, the uplink TCI state of the foregoing at least one first candidate cell, the downlink bandwidth part (BWP) of the foregoing at least one first candidate cell, the uplink BWP of the foregoing at least one first candidate cell, the first SSB metric, and the first CSI-RS metric;

[0185] Wherein, when the conditional handover command further indicates the preamble of the foregoing at least one first candidate cell, during the random access process of the terminal device with the target cell, the terminal device may carry the preamble of the target cell in the message sent to the target cell. Further, the terminal device receives a message from the target cell, and the message from the target cell may carry the time advance required for uplink synchronization with the target cell. Alternatively, the conditional handover command may directly indicate the time advance required for uplink synchronization with the target cell.

[0186] The downlink TCI state of the at least one first candidate cell may indicate the relevant information of the transmission beam adopted by the network device to which the at least one first candidate cell belongs. The uplink TCI state of the at least one first candidate cell may indicate the relevant information of the receiving beam adopted by the network device to which the at least one first candidate cell belongs. Taking the number of the at least one first candidate cell being 2, and the two first candidate cells being candidate cell 1 and candidate cell 2 as an example, the downlink TCI state of the at least one first candidate cell may indicate: the relevant information of the transmission beam a adopted by the candidate network device 1 to which candidate cell 1 belongs, and the relevant information of the transmission beam b adopted by the candidate network device 2 to which candidate cell 2 belongs. In this way, the terminal device may use the receiving beam a corresponding to the transmission beam a to receive information from the candidate network device 1, and the terminal device may use the receiving beam b corresponding to the transmission beam b to receive information from the candidate network device 2. The uplink TCI state of the at least one first candidate cell may indicate: the relevant information of the receiving beam c adopted by the candidate network device 1 to which candidate cell 1 belongs, and the relevant information of the receiving beam d adopted by the candidate network device 2 to which candidate cell 2 belongs. In this way, the terminal device may use the transmission beam c corresponding to the receiving beam c to send information to the candidate network device 1, and the terminal device may use the transmission beam d corresponding to the receiving beam d to send information to the candidate network device 2.

[0187] The downlink BWP of the foregoing at least one first candidate cell can be used for downlink data transmission after access, and the uplink BWP of the foregoing at least one first candidate cell can be used for uplink data transmission after access. For example, taking the number of the at least one first candidate cell as 2, and the 2 first candidate cells being candidate cell 1 and candidate cell 2 respectively, wherein, the uplink BWP of candidate cell 1 can be used for uplink data transmission after the terminal device accesses candidate cell 1, and the uplink BWP of candidate cell 2 can be used for uplink data transmission after the terminal device accesses candidate cell 2.

[0188] The layer 1 measurement results of the foregoing at least one first candidate cell reported by the terminal device may include the measurement results of at least one SSB metric and / or the measurement results of at least one CSI-RS metric. The at least one SSB metric includes a first SSB metric, and the at least one CSI-RS metric includes a first CSI-RS metric.

[0189] When the layer 1 measurement results of the foregoing at least one first candidate cell reported by the terminal device include the measurement results of at least one SSB metric, the conditional handover command may instruct the terminal device to evaluate the measurement results of some of the at least one SSB metric (i.e., the first SSB metric) to evaluate whether to perform a conditional handover. Similarly, when the layer 1 measurement results of the foregoing at least one first candidate cell reported by the terminal device include the measurement results of at least one CSI-RS metric, the conditional handover command may instruct the terminal device to evaluate the measurement results of some of the at least one CSI-RS metric (i.e., the first CSI-RS metric) to evaluate whether to perform a conditional handover.

[0190] It can be understood that when the conditional handover command indicates the first SSB metric, that the layer 1 measurement results of the target cell meet the conditional handover trigger condition of the target cell may include: the measurement results of the first SSB metric of the target cell meet the conditional handover trigger condition of the target cell. When the conditional handover command indicates the first CSI-RS metric, that the layer 1 measurement results of the target cell meet the conditional handover trigger condition of the target cell may include: the measurement results of the first CSI-RS metric of the target cell meet the conditional handover trigger condition of the target cell.

[0191] Wherein, the at least one SSB metric may include but is not limited to: synchronization signal (SS)-RSRP, SS-SINR. The at least one CSI-RS metric may include but is not limited to: CSI-RSRP, CSI-SINR.

[0192] Please refer to Figure 6 , Figure 6It is a schematic structural diagram of a communication device provided by an embodiment of the present application. As Figure 6 shown, the communication device 60 includes a receiving unit 601 and a switching unit 602. Optionally, the communication device 60 may further include a transmitting unit 603. Figure 6 The units shown by the dashed lines in are optional units. That is to say, the communication device 60 may not include Figure 6 the units shown by the dashed lines in. The communication device 60 may perform the relevant steps of the terminal device in the foregoing method embodiment.

[0193] The receiving unit 601 is configured to receive layer 2 signaling, where the layer 2 signaling includes a conditional handover command, and the conditional handover command indicates to perform a conditional handover;

[0194] The switching unit 602 is configured to initiate a handover to a target cell if there is a target cell that meets the conditional handover trigger condition among at least one first candidate cell for the conditional handover.

[0195] In a possible implementation manner, the conditional handover command further indicates to perform a conditional handover based on the layer 1 measurement results of the foregoing at least one first candidate cell, and that the target cell meets the conditional handover trigger condition includes: the layer 1 measurement results of the target cell meet the conditional handover trigger condition of the target cell.

[0196] In a possible implementation manner, the conditional handover command includes information about the foregoing at least one first candidate cell.

[0197] In a possible implementation manner, the receiving unit 601 is further configured to receive first indication information; where the first indication information is used to indicate the foregoing at least one first candidate cell; or the first indication information is used to indicate at least one second candidate cell, and the at least one second candidate cell includes the foregoing at least one first candidate cell.

[0198] In a possible implementation manner, the number of the foregoing at least one first candidate cell is N1, the number of the foregoing at least one second candidate cell is N2, the conditional handover command is carried by at least a first bit field, the first bit field includes N2 bit positions, and one bit position in the N2 bit positions corresponds to one second candidate cell among the N2 second candidate cells; where, among the N2 bit positions, the N1 bit positions corresponding to the N1 first candidate cells take a first value.

[0199] In a possible implementation manner, the transmitting unit 603 is configured to transmit the layer 1 measurement results of the foregoing at least one second candidate cell.

[0200] In a possible implementation, the conditional handover command further indicates one or more of the following: the conditional handover trigger condition of the at least one first candidate cell, the timing advance information of the at least one first candidate cell, the preamble of the at least one first candidate cell, the downlink TCI state of the at least one first candidate cell, the uplink TCI state of the at least one first candidate cell, the downlink BWP of the at least one first candidate cell, the uplink BWP of the at least one first candidate cell, the first SSB metric, the first CSI-RS metric;

[0201] Wherein, the layer 1 measurement result of the at least one first candidate cell includes the measurement result of at least one SSB metric and / or the measurement result of at least one CSI-RS metric, the at least one SSB metric includes the first SSB metric, the at least one CSI-RS metric includes the first CSI-RS metric, and the layer 1 measurement result of the target cell satisfying the conditional handover trigger condition of the target cell includes: the measurement result of the first SSB metric of the target cell and / or the measurement result of the first CSI-RS metric of the target cell satisfying the conditional handover trigger condition of the target cell.

[0202] In a possible implementation, the conditional handover trigger condition of the at least one first candidate cell includes one or more of the following: signal quality trigger condition, distance trigger condition, time trigger condition;

[0203] The layer 1 measurement result of the target cell satisfying the conditional handover trigger condition of the target cell includes one or more of the following: the layer 1 measurement result of the signal quality of the target cell satisfying the signal quality trigger condition of the target cell, the distance between the terminal device and the reference position of the target cell satisfying the distance trigger condition of the target cell, the first moment satisfying the time trigger condition of the target cell, wherein the first moment is the moment when the layer 1 measurement result of the signal quality of the target cell satisfies the signal quality trigger condition of the target cell.

[0204] In a possible implementation, the moment when it is determined that the target cell satisfies the conditional handover trigger condition is earlier than the moment when it is determined to initiate the first handover to the first cell; and / or, the priority of the handover to the target cell is higher than the priority of the first handover; wherein, the first handover and the conditional handover have different handover types, and the candidate cell set of the first handover includes the first cell.

[0205] In a possible implementation, the handover unit 602 is further configured to, if the moment when it is determined that the target cell satisfies the conditional handover trigger condition is later than the moment when it is determined to initiate the first handover to the first cell, and / or, the priority of the handover to the target cell is lower than the priority of the first handover, initiate the first handover to the first cell; wherein, the first handover and the conditional handover have different handover types, and the candidate cell set of the first handover includes the first cell.

[0206] In a possible implementation, the Layer 2 signaling is MAC-CE.

[0207] Specifically, in this case, the operations performed by the receiving unit 601, the switching unit 602, and the transmitting unit 603 may refer to Figure 4 - Figure 5 the introduction of the terminal device in the corresponding embodiment.

[0208] Please refer to Figure 7 , Figure 7 which is a schematic structural diagram of another communication device provided in an embodiment of the present application. As Figure 7 shown, the communication device 70 includes a transmitting unit 701. Optionally, the communication device 70 may further include a receiving unit 702 and a determining unit 703. Figure 7 The units shown by the dashed lines in Figure 7 are optional units, that is to say, the communication device 70 may not include

[0209] The transmitting unit 701 is configured to transmit Layer 2 signaling, and the Layer 2 signaling includes a conditional handover command, and the conditional handover command indicates to perform a conditional handover.

[0210] In a possible implementation, the conditional handover command is further used to indicate a conditional handover based on the Layer 1 measurement results of at least one first candidate cell.

[0211] In a possible implementation, the conditional handover command includes information of the at least one first candidate cell.

[0212] In a possible implementation, the transmitting unit 701 is further configured to transmit first indication information; wherein, the first indication information is used to indicate the at least one first candidate cell; or, the first indication information is used to indicate at least one second candidate cell, and the at least one second candidate cell includes the at least one first candidate cell.

[0213] In a possible implementation, the number of the at least one first candidate cell is N1, the number of the at least one second candidate cell is N2, the conditional handover command is carried by at least a first bit field, the first bit field includes N2 bit positions, and one bit position among the N2 bit positions corresponds to one second candidate cell among the N2 second candidate cells; wherein, among the N2 bit positions, the N1 bit positions corresponding to the N1 first candidate cells take a first value.

[0214] In a possible implementation, a receiving unit 702 is configured to receive layer 1 measurement results of the at least one second candidate cell; a determining unit 703 is configured to determine the at least one first candidate cell from the at least one second candidate cell based on the layer 1 measurement results of the at least one second candidate cell.

[0215] In a possible implementation, the conditional handover command is further configured to indicate one or more of the following: a conditional handover trigger condition of the at least one first candidate cell, timing advance information of the at least one first candidate cell, a preamble of the at least one first candidate cell, a downlink TCI state of the at least one first candidate cell, an uplink TCI state of the at least one first candidate cell, a downlink BWP of the at least one first candidate cell, an uplink BWP of the at least one first candidate cell, a first SSB metric, a first CSI-RS metric; wherein, the layer 1 measurement results of the at least one first candidate cell include measurement results of at least one SSB metric and / or measurement results of at least one CSI-RS metric, the at least one SSB metric includes the first SSB metric, and the at least one CSI-RS metric includes the first CSI-RS metric.

[0216] In a possible implementation, the conditional handover trigger condition of the at least one first candidate cell includes one or more of the following: a signal quality trigger condition, a distance trigger condition, a time trigger condition.

[0217] In a possible implementation, the layer 2 signaling is MAC-CE.

[0218] Specifically, in this case, the operations performed by the sending unit 701, the receiving unit 702, and the determining unit 703 may refer to Figure 4 - Figure 5 the description of the source network device in the corresponding embodiment.

[0219] Please refer to Figure 8 , Figure 8 Another communication device 80 provided in an embodiment of the present application. It can be used to implement the functions of the terminal device in the above method embodiment, or implement the functions of the source network device in the above method embodiment. The communication device 80 may include a transceiver 801 and a processor 802. Optionally, the communication device may further include a memory 803. Wherein, the transceiver 801, the processor 802, and the memory 803 may be connected through a bus 804 or other means. The bus is Figure 8 shown in thick lines in Figure 8 . The connection manners between other components are only schematically illustrated and are not limited thereto. The bus may be divided into an address bus, a data bus, a control bus, etc. For the sake of simplicity of representation,

[0220] The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units or modules, which can be electrical, mechanical or other forms for information interaction between devices, units or modules. In the embodiments of the present application, the specific connection medium between the transceiver 801, the processor 802, and the memory 803 is not limited.

[0221] The memory 803 may include a read-only memory and a random access memory, and provide instructions and data to the processor 802. A part of the memory 803 may also include a non-volatile random access memory.

[0222] The processor 802 may be a central processing unit (CPU), and the processor 802 may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor. Optionally, the processor 802 may also be any conventional processor, etc.

[0223] In one example, when the terminal device adopts Figure 8 the form shown, Figure 8 the processor in

[0224] In one example, when the network device adopts Figure 8 the form shown, Figure 8 the processor in

[0225] In an alternative embodiment, the memory 803 is used to store program instructions; the processor 802 is used to call the program instructions stored in the memory 803 to execute Figure 4 - Figure 5 the steps performed by the terminal device or the source network device in the corresponding embodiments.

[0226] Specifically, Figure 6 the functions / implementation processes of the receiving unit, the switching unit, and the transmitting unit in Figure 8 can all be implemented by the processor 802 in Figure 6 calling the computer execution instructions stored in the memory 803. Or, Figure 8The processor 802 in Figure 6 calls the computer-executable instructions stored in the memory 803 to implement, Figure 8 and the functions / implementation processes of the receiving unit and the sending unit in Figure 7 can be implemented by the transceiver 801 in Figure 8 The functions / implementation processes of the sending unit, the receiving unit, and the determining unit in Figure 7 can all be implemented by the processor 802 in Figure 8 calling the computer-executable instructions stored in the memory 803. Or, Figure 7 the function / implementation process of the determining unit in Figure 8 can be implemented by the processor 802 in

[0227] calling the computer-executable instructions stored in the memory 803, and the functions / implementation processes of the receiving unit and the sending unit in

[0228] can be implemented by the transceiver 801 in

[0229] In the embodiments of the present application, the method provided in the embodiments of the present application can be implemented by running a computer program (including program code) capable of executing the steps involved in the above method on a general computing device such as a computer including processing elements and storage elements such as a CPU, a random access memory (RAM), and a read-only memory (ROM). The computer program can be recorded on a computer-readable recording medium, for example, and loaded into the above computing device through the computer-readable recording medium and run therein.

[0228] Based on the same inventive concept, the principle of solving problems and the beneficial effects of the communication device 80 provided in the embodiments of the present application are similar to the principle of solving problems and the beneficial effects of the terminal device and the network device in the method embodiments of the present application. For the principle and beneficial effects of the method implementation, reference can be made thereto. For the sake of brevity of description, it will not be elaborated herein.

[0229] The foregoing communication device (such as the communication device 60, the communication device 70, and the communication device 80) can be, for example: a chip or a chip module.

[0230] The embodiments of the present application further provide a chip, and the chip can execute the relevant steps of the terminal device and the source network device in the foregoing method embodiments.

[0231] For the case where the chip is used to implement the functions of the terminal device in the above method embodiments:

[0232] The chip is used to receive layer 2 signaling, and the layer 2 signaling includes a conditional handover command, and the conditional handover command instructs to perform a conditional handover; if there is a target cell that meets the conditional handover trigger condition among at least one first candidate cell for the conditional handover, a handover is initiated to the target cell.

[0233] In a possible implementation, the conditional handover command further indicates a conditional handover based on the layer 1 measurement results of the foregoing at least one first candidate cell, and the target cell satisfying the conditional handover trigger condition includes: the layer 1 measurement results of the target cell satisfying the conditional handover trigger condition of the target cell.

[0234] In a possible implementation, the conditional handover command includes information on the foregoing at least one first candidate cell.

[0235] In a possible implementation, the chip is further configured to receive first indication information; wherein, the first indication information is used to indicate the foregoing at least one first candidate cell; or, the first indication information is used to indicate at least one second candidate cell, and the at least one second candidate cell includes the foregoing at least one first candidate cell.

[0236] In a possible implementation, the number of the foregoing at least one first candidate cell is N1, the number of the foregoing at least one second candidate cell is N2, the conditional handover command is carried by at least a first bit field, the first bit field includes N2 bit positions, and one bit position among the N2 bit positions corresponds to one second candidate cell among the N2 second candidate cells; wherein, among the N2 bit positions, the N1 bit positions corresponding to the N1 first candidate cells take a first value.

[0237] In a possible implementation, the chip is further configured to send the layer 1 measurement results of the foregoing at least one second candidate cell.

[0238] In a possible implementation, the conditional handover command further indicates one or more of the following: the conditional handover trigger condition of the foregoing at least one first candidate cell, the timing advance information of the foregoing at least one first candidate cell, the preamble of the foregoing at least one first candidate cell, the downlink TCI state of the foregoing at least one first candidate cell, the uplink TCI state of the foregoing at least one first candidate cell, the downlink BWP of the foregoing at least one first candidate cell, the uplink BWP of the foregoing at least one first candidate cell, a first SSB metric, a first CSI-RS metric;

[0239] Wherein, the layer 1 measurement results of the at least one first candidate cell include the measurement results of at least one SSB metric and / or the measurement results of at least one CSI-RS metric, the at least one SSB metric includes a first SSB metric, the at least one CSI-RS metric includes a first CSI-RS metric, and the layer 1 measurement results of the target cell satisfying the conditional handover trigger condition of the target cell include: the measurement results of the first SSB metric and / or the first CSI-RS metric of the target cell satisfying the conditional handover trigger condition of the target cell.

[0240] In a possible implementation, the condition handover triggering conditions for the at least one first candidate cell include one or more of the following: signal quality triggering condition, distance triggering condition, time triggering condition;

[0241] That the layer 1 measurement result of the target cell satisfies the condition handover triggering condition of the target cell includes one or more of the following: the layer 1 measurement result of the signal quality of the target cell satisfies the signal quality triggering condition of the target cell, the distance between the terminal device and the reference position of the target cell satisfies the distance triggering condition of the target cell, the first moment satisfies the time triggering condition of the target cell, where the first moment is the moment when the layer 1 measurement result of the signal quality of the target cell satisfies the signal quality triggering condition of the target cell.

[0242] In a possible implementation, the moment when it is determined that the target cell satisfies the condition handover triggering condition is earlier than the moment when it is determined to initiate a first handover to the first cell; and / or, the priority of the handover to the target cell is higher than the priority of the first handover; where the first handover and the condition handover have different handover types, and the candidate cell set of the first handover includes the first cell.

[0243] In a possible implementation, the chip is further configured to initiate a first handover to the first cell if the moment when it is determined that the target cell satisfies the condition handover triggering condition is later than the moment when it is determined to initiate a first handover to the first cell, and / or, the priority of the handover to the target cell is lower than the priority of the first handover; where the first handover and the condition handover have different handover types, and the candidate cell set of the first handover includes the first cell.

[0244] In a possible implementation, the layer 2 signaling is MAC-CE.

[0245] Specifically, in this case, the operations performed by the chip may refer to the introduction of the terminal device in the corresponding embodiment above. Figure 4 - Figure 5 corresponding embodiment regarding the introduction of the terminal device.

[0246] In an implementation, for the case where the chip is used to implement the functions of the source network device in the above method embodiments:

[0247] The chip is configured to: send layer 2 signaling, where the layer 2 signaling includes a condition handover command, and the condition handover command indicates to perform a condition handover.

[0248] In a possible implementation, the condition handover command is further used to indicate to perform a condition handover based on the layer 1 measurement results of the at least one first candidate cell.

[0249] In a possible implementation, the condition handover command includes information about the at least one first candidate cell.

[0250] In a possible implementation, the chip is further configured to send first indication information; wherein, the first indication information is used to indicate the at least one first candidate cell; or, the first indication information is used to indicate at least one second candidate cell, and the at least one second candidate cell includes the at least one first candidate cell.

[0251] In a possible implementation, the number of the at least one first candidate cell is N1, the number of the at least one second candidate cell is N2, and the conditional handover command is carried by at least a first bit field, the first bit field includes N2 bits, and one bit in the N2 bits corresponds to one second candidate cell among the N2 second candidate cells; wherein, among the N2 bits, the values of the N1 bits corresponding to the N1 first candidate cells are a first value.

[0252] In a possible implementation, the chip is further configured to receive layer 1 measurement results of the at least one second candidate cell; and determine the at least one first candidate cell from the at least one second candidate cell based on the layer 1 measurement results of the at least one second candidate cell.

[0253] In a possible implementation, the conditional handover command is further used to indicate one or more of the following: the conditional handover trigger condition of the at least one first candidate cell, the timing advance information of the at least one first candidate cell, the preamble of the at least one first candidate cell, the downlink TCI state of the at least one first candidate cell, the uplink TCI state of the at least one first candidate cell, the downlink BWP of the at least one first candidate cell, the uplink BWP of the at least one first candidate cell, a first SSB metric, a first CSI-RS metric; wherein, the layer 1 measurement results of the at least one first candidate cell include measurement results of at least one SSB metric and / or measurement results of at least one CSI-RS metric, the at least one SSB metric includes the first SSB metric, and the at least one CSI-RS metric includes the first CSI-RS metric.

[0254] In a possible implementation, the conditional handover trigger condition of the at least one first candidate cell includes one or more of the following: a signal quality trigger condition, a distance trigger condition, a time trigger condition.

[0255] In a possible implementation, the layer 2 signaling is MAC-CE.

[0256] Specifically, in this case, the operations performed by the chip may refer to the introduction of the source network device in the corresponding Figure 4 - Figure 5 embodiment described above.

[0257] In a possible implementation, the above chip includes at least one processor, at least one first memory, and at least one second memory; wherein, the above at least one first memory and the above at least one processor are interconnected by a circuit, and instructions are stored in the first memory; the above at least one second memory and the above at least one processor are interconnected by a circuit, and data required in the method embodiments is stored in the second memory.

[0258] For each device and product applied to or integrated into the chip, each module included therein may be implemented in a hardware manner such as a circuit, or at least some modules may be implemented in a software program manner, and the software program runs on a processor integrated inside the chip, and the remaining (if any) part of the modules may be implemented in a hardware manner such as a circuit.

[0259] Based on the same inventive concept, the principle and beneficial effects of the chip provided in the embodiments of the present application for solving problems are similar to the principle and beneficial effects of the terminal device and the source network device in the method embodiments of the present application. The principle and beneficial effects of the method implementation can be referred to. For the sake of brevity, they will not be elaborated here.

[0260] Please refer to Figure 9 , Figure 9 which is a schematic structural diagram of a chip module provided in the embodiments of the present application. The chip module 90 may execute the relevant steps of the terminal device and the source network device in the foregoing method embodiments. The chip module 90 includes: a communication interface 901 and a chip 902.

[0261] Among them, the communication interface is used for internal communication within the chip module or for communication between the chip module and external devices; the chip is used to implement the functions of the terminal device and the source network device in the embodiments of the present application. For details, please refer to Figure 4 - Figure 5 the corresponding embodiments. Optionally, the chip module 90 may further include a storage module 903 and a power supply module 904. The storage module 903 is used to store data and instructions. The power supply module 904 is used to supply electrical energy to the chip module.

[0262] For each device and product applied to or integrated into the chip module, each module included therein may be implemented in a hardware manner such as a circuit. Different modules may be located in the same component (such as a chip, a circuit module, etc.) or different components of the chip module, or at least some modules may be implemented in a software program manner, and the software program runs on a processor integrated inside the chip module, and the remaining (if any) part of the modules may be implemented in a hardware manner such as a circuit.

[0263] The embodiments of the present application further provide a computer-readable storage medium. A computer program is stored in the computer-readable storage medium. The computer program includes one or more program instructions, and the one or more program instructions are adapted to be loaded and executed by a communication device to perform the method provided in the foregoing method embodiments.

[0264] The embodiments of the present application further provide a computer program product including a computer program or instructions. When the computer program or instructions run on a computer, the computer is caused to execute the method provided in the foregoing method embodiments.

[0265] Regarding the various modules / units included in the various devices and products described in the foregoing embodiments, they may be software modules / units, or hardware modules / units, or may be partly software modules / units and partly hardware modules / units. For example, for the various devices and products applied to or integrated into a chip, the various modules / units included therein may all be implemented in the form of hardware such as circuits. Or, at least some of the modules / units may be implemented in the form of a software program that runs on a processor integrated inside the chip, and the remaining (if any) part of the modules / units may be implemented in the form of hardware such as circuits; for the various devices and products applied to or integrated into a chip module, the various modules / units included therein may all be implemented in the form of hardware such as circuits. Different modules / units may be located in the same component (such as a chip, a circuit module, etc.) or different components of the chip module. Or, at least some of the modules / units may be implemented in the form of a software program that runs on a processor integrated inside the chip module, and the remaining (if any) part of the modules / units may be implemented in the form of hardware such as circuits; for the various devices and products applied to or integrated into a terminal, the various modules / units included therein may all be implemented in the form of hardware such as circuits. Different modules / units may be located in the same component (such as a chip, a circuit module, etc.) or different components inside the terminal. Or, at least some of the modules / units may be implemented in the form of a software program that runs on a processor integrated inside the terminal, and the remaining (if any) part of the modules / units may be implemented in the form of hardware such as circuits.

[0266] It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, some steps may be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0267] In the above embodiments, the descriptions of the various embodiments have their own focuses, and any number of embodiments can be combined and used. For the parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0268] The steps in the method of the embodiments of the present application can be adjusted, combined, and deleted according to actual needs.

[0269] The modules in the device of the embodiments of the present application can be combined, divided, and deleted according to actual needs.

[0270] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by program instructions and related hardware. The program instructions can be stored in a computer-readable storage medium, and the computer-readable storage medium can include: flash drives, ROM, RAM, magnetic disks, or optical discs, etc.

[0271] What is disclosed above is only one embodiment of the present application, and it is only a part of the embodiments of the present application. It cannot be used to limit the scope of the rights of the present application.

Claims

1. A handover method, characterized in that, the method includes: Receiving layer 2 signaling, where the layer 2 signaling includes a conditional handover command that indicates a conditional handover; If there is a target cell that meets the conditional handover trigger condition among at least one first candidate cell for conditional handover, initiate a handover to the target cell.

2. The method according to claim 1, characterized in that, the conditional handover command further indicates a conditional handover based on the layer 1 measurement results of the at least one first candidate cell, and the target cell meeting the conditional handover trigger condition includes: the layer 1 measurement results of the target cell meeting the conditional handover trigger condition of the target cell.

3. The method according to claim 2, characterized in that, the conditional handover command includes information of the at least one first candidate cell.

4. The method according to claim 2, characterized in that, the method further includes: Receiving first indication information; wherein, the first indication information is used to indicate the at least one first candidate cell; or, the first indication information is used to indicate at least one second candidate cell, and the at least one second candidate cell includes the at least one first candidate cell.

5. The method according to claim 4, characterized in that, the number of the at least one first candidate cell is N1, the number of the at least one second candidate cell is N2, the conditional handover command is carried by at least a first bit field, the first bit field includes N2 bit positions, and one bit position among the N2 bit positions corresponds to one second candidate cell among the N2 second candidate cells; wherein, among the N2 bit positions, the values of the N1 bit positions corresponding to the N1 first candidate cells are a first value.

6. The method according to claim 4 or 5, characterized in that, the method further includes: Sending the layer 1 measurement results of the at least one second candidate cell.

7. The method according to any one of claims 2-6, characterized in that, the conditional handover command further indicates one or more of the following: the conditional handover trigger condition of the at least one first candidate cell, the timing advance information of the at least one first candidate cell, the preamble of the at least one first candidate cell, the downlink TCI state of the at least one first candidate cell, the uplink TCI state of the at least one first candidate cell, the downlink BWP of the at least one first candidate cell, the uplink BWP of the at least one first candidate cell, the first SSB metric, the first CSI-RS metric; Among them, the layer 1 measurement results of the at least one first candidate cell include the measurement results of at least one SSB metric and / or the measurement results of at least one CSI-RS metric. The at least one SSB metric includes the first SSB metric, and the at least one CSI-RS metric includes the first CSI-RS metric. The layer 1 measurement results of the target cell satisfying the conditional handover trigger condition of the target cell include: the measurement results of the first SSB metric of the target cell and / or the measurement results of the first CSI-RS metric satisfying the conditional handover trigger condition of the target cell.

8. The method according to any one of claims 2-7, wherein, the conditional handover trigger conditions of the at least one first candidate cell include one or more of the following: signal quality trigger condition, distance trigger condition, time trigger condition; the layer 1 measurement results of the target cell satisfying the conditional handover trigger condition of the target cell include one or more of the following: the layer 1 measurement results of the signal quality of the target cell satisfying the signal quality trigger condition of the target cell, the distance of the terminal device from the reference position of the target cell satisfying the distance trigger condition of the target cell, the first moment satisfying the time trigger condition of the target cell, where the first moment is the moment when the layer 1 measurement results of the signal quality of the target cell satisfy the signal quality trigger condition of the target cell.

9. The method according to any one of claims 1-8, wherein, the moment of determining that the target cell satisfies the conditional handover trigger condition is earlier than the moment of determining to initiate a first handover to the first cell; and / or, the priority of the handover to the target cell is higher than the priority of the first handover; wherein, the handover types of the first handover and the conditional handover are different, and the candidate cell set of the first handover includes the first cell.

10. The method according to any one of claims 1-8, wherein, the method further includes: if the moment of determining that the target cell satisfies the conditional handover trigger condition is later than the moment of determining to initiate a first handover to the first cell, and / or, the priority of the handover to the target cell is lower than the priority of the first handover, initiate the first handover to the first cell; wherein, the handover types of the first handover and the conditional handover are different, and the candidate cell set of the first handover includes the first cell.

11. The method according to any one of claims 1-10, wherein, the layer 2 signaling is MAC-CE.

12. A handover method, wherein, the method includes: sending layer 2 signaling, the layer 2 signaling includes a conditional handover command, and the conditional handover command instructs to perform a conditional handover.

13. The method according to claim 12, wherein, the conditional handover command is further used to instruct to perform a conditional handover based on the layer 1 measurement results of at least one first candidate cell.

14. The method according to claim 13, wherein, the conditional handover command includes the information of the at least one first candidate cell.

15. The method according to claim 13, wherein, the method further comprises, sending first indication information; wherein, the first indication information is used to indicate the at least one first candidate cell; or, the first indication information is used to indicate at least one second candidate cell, and the at least one second candidate cell includes the at least one first candidate cell.

16. The method according to claim 15, wherein, the number of the at least one first candidate cell is N1, the number of the at least one second candidate cell is N2, the conditional handover command is carried by at least a first bit field, the first bit field includes N2 bit positions, and one bit position among the N2 bit positions corresponds to one second candidate cell among the N2 second candidate cells; wherein, among the N2 bit positions, the N1 bit positions corresponding to the N1 first candidate cells take a first value.

17. The method according to claim 15 or 16, wherein, the method further comprises: receiving layer 1 measurement results of the at least one second candidate cell; determining the at least one first candidate cell from the at least one second candidate cell based on the layer 1 measurement results of the at least one second candidate cell.

18. The method according to any one of claims 13-17, wherein, the conditional handover command is further used to indicate one or more of the following: the conditional handover trigger condition of the at least one first candidate cell, the timing advance information of the at least one first candidate cell, the preamble of the at least one first candidate cell, the downlink TCI state of the at least one first candidate cell, the uplink TCI state of the at least one first candidate cell, the downlink BWP of the at least one first candidate cell, the uplink BWP of the at least one first candidate cell, a first SSB metric, a first CSI-RS metric; wherein, the layer 1 measurement results of the at least one first candidate cell include measurement results of at least one SSB metric and / or measurement results of at least one CSI-RS metric, the at least one SSB metric includes the first SSB metric, and the at least one CSI-RS metric includes the first CSI-RS metric.

19. The method according to any one of claims 13-18, wherein, the conditional handover trigger condition of the at least one first candidate cell includes one or more of the following: a signal quality trigger condition, a distance trigger condition, a time trigger condition.

20. The method according to any one of claims 12-19, wherein, the layer 2 signaling is MAC-CE.

21. A communication device, wherein, the device comprises a receiving unit and a handover unit; the receiving unit is configured to receive layer 2 signaling, the layer 2 signaling includes a conditional handover command, and the conditional handover command indicates a conditional handover; the handover unit is configured to initiate a handover to a target cell if there is a target cell that meets the conditional handover trigger condition among the at least one first candidate cells for the conditional handover.

22. A communication device, wherein, The device includes a sending unit; The sending unit is configured to send Layer 2 signaling, and the Layer 2 signaling includes a conditional handover command, and the conditional handover command indicates to perform a conditional handover.

23. A communication device, characterized in that it includes a processor; The processor is configured to execute the method according to any one of claims 1 to 11 or 12 to 20.

24. A chip, characterized in that the chip is configured to execute the method according to any one of claims 1 to 11 or 12 to 20.

25. A chip module, characterized in that the chip module includes a communication interface and a chip, wherein: the communication interface is used for internal communication of the chip module or for communication between the chip module and an external device; the chip is configured to execute the method according to any one of claims 1 to 11 or 12 to 20.

26. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, the computer program includes program instructions, and when the program instructions are executed by a communication device, the method according to any one of claims 1 to 11 or 12 to 20 is executed.

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