Communication method and apparatus

Abstract

A communication method and apparatus. The method comprises: a first entity acquiring information of a plurality of candidate cells of a terminal device; and after it is determined that the terminal device is handed over to a first candidate cell of a first candidate entity, the first entity sending first information according to the information of the plurality of candidate cells, the first information instructing the release of a second candidate cell, wherein the first candidate cell is one of the plurality of candidate cells, and the second candidate cell is one of the plurality of candidate cells; and the first entity may be a service entity, a source entity or a candidate entity. On the basis of the solution, the first entity may instruct the release of some candidate cells, such that the terminal device saves a suitable set of candidate cells, thereby reducing the determination implementation complexity of the terminal device. In addition, a candidate entity is enabled to release, in a timely manner, a radio cell resource which is reserved for the terminal device, so as to avoid the situation that the radio cell resource cannot be allocated to other terminal devices due to excessive occupation of the resource by the terminal device, thereby realizing efficient utilization of cell resources.

Description

Communication method and device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on September 6, 2023, with application number 202311148981.X and application name “A Communication Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of communications, and in particular to a communication method and apparatus. Background Art

[0003] In terminal device mobility management, the network can pre-configure multiple candidate cells and their corresponding trigger conditions for the terminal device. After receiving this configuration, the terminal device can determine whether the trigger conditions corresponding to each candidate cell are met. If the trigger conditions corresponding to a candidate cell are met, the candidate cell is selected as the target cell and access is made to the target cell.

[0004] After accessing the target cell, the terminal device may still save the previous candidate cell configuration and continue to evaluate the target cell based on the configuration information related to the candidate cell. However, there is currently no solution for how to release these candidate cells.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a communication method and apparatus that can timely release candidate cells of a terminal device and improve the utilization rate of cell wireless resources.

[0007] In a first aspect, a communication method is provided. The method can be performed by a first entity, or by a component of the first entity, such as a processor, chip, or chip system of the first entity, or by a logic module or software capable of implementing all or part of the functions of the first entity. The method includes: obtaining information about multiple candidate cells of a terminal device; determining that the terminal device is to switch to a first candidate cell of the first candidate entity, where the first candidate cell is one of the multiple candidate cells; and sending first information based on the information about the multiple candidate cells, where the first information indicates the release of a second candidate cell, where the second candidate cell is one or more of the multiple candidate cells.

[0008] Based on this solution, a first entity (such as a service entity, a source entity, or a candidate entity of a terminal device) can determine that the terminal device has accessed a first candidate cell and send a first message to instruct the release of one or more other candidate cells. When the first entity sends the first message to the candidate entity to which the candidate cell to be released belongs, the candidate entity can release the cell radio resources reserved for the terminal device in a timely manner, thereby avoiding the situation where the terminal device excessively occupies the cell radio resources and cannot allocate the resources to other terminal devices, thereby achieving efficient utilization of cell resources.

[0009] In one possible design, obtaining information about multiple candidate cells of a terminal device includes: receiving information about multiple candidate cells from a source entity.

[0010] Based on this possible design, when the first entity is a service entity or a candidate entity of the terminal device, the source entity can send information of multiple candidate cells to the first entity, so that the first entity can know the multiple candidate cells of the terminal device, thereby determining the cell that needs to be released from the multiple candidate cells, and then releasing the candidate cells of the terminal device in a timely manner.

[0011] In one possible design, sending the first information includes: sending the first information to the source entity or the second candidate entity, where the second candidate entity is an entity to which the second candidate cell belongs.

[0012] Based on this possible design, when the first entity is a service entity of the terminal device, the service entity can send first information to the source entity to instruct the release of the second candidate cell, so that the source entity can send information to the second candidate entity to instruct the release of the second candidate cell. Alternatively, the service entity can send the first information to the second candidate entity to instruct the release of the second candidate cell. That is, the second candidate entity can be informed of the need to release the second candidate cell, so that the second candidate entity can promptly release the cell radio resources reserved for the terminal device, avoiding the situation where the terminal device excessively occupies the cell radio resources and cannot allocate the resources to other terminal devices, thereby achieving efficient utilization of cell resources.

[0013] In one possible design, the method also includes: sending second information to the terminal device, where the second information indicates releasing configuration information of the second candidate cell.

[0014] Based on this possible design, the first candidate entity sends a second information to the terminal device to instruct the terminal device to release the second candidate cell, so that the terminal device can release or deactivate the configuration information of the second candidate cell, thereby not continuing to evaluate whether the second candidate cell can be used as the target cell in the subsequent switching process, which can reduce the judgment complexity and power consumption of the terminal device.

[0015] In one possible design, sending the second information to the terminal device includes: sending configuration information of the first candidate cell to the terminal device, the configuration information of the first candidate cell includes the second information, and the configuration information of the first candidate cell is used for the terminal device to access the first candidate cell.

[0016] Based on this possible design, the first entity can indicate the second candidate cell when configuring the first candidate cell for the terminal device, so that the terminal device can know that the second candidate cell can be released when switching to the first candidate cell. This eliminates the need to indicate the second information through a separate RRC message, which can reduce signaling overhead.

[0017] In one possible design, determining that the terminal device switches to a first candidate cell of the first candidate entity includes: receiving third information from the first candidate entity, where the third information instructs the terminal device to switch to the first candidate cell.

[0018] Based on this possible design, when the first entity is the source entity or the second candidate entity, the first entity can learn through the third information that the terminal device has switched to the first candidate cell, so that it can send the first information based on the information of multiple candidate cells, and then release the candidate cell of the terminal device in time.

[0019] In one possible design, sending the first information includes: sending the first information to a first candidate entity.

[0020] Based on this possible design, when the first entity is the source entity or the second candidate entity, the first entity sends the first information to the first candidate entity, which enables the first candidate entity to send information to the second terminal device to indicate the release of the configuration information of the second candidate cell, so that the terminal device can release or deactivate the configuration information of the second candidate cell, and no longer continue to evaluate whether the second candidate cell can be used as the target cell in the subsequent switching process, thereby reducing the judgment complexity and power consumption of the terminal device.

[0021] In one possible design, the first information includes at least one of the following: identification information of the second candidate cell, identification information allocated by the source entity to the terminal device, identification information allocated by the second candidate entity to the terminal device, or identification information of the source entity, and the second candidate entity is the entity to which the second candidate cell belongs.

[0022] In one possible design, the second candidate cell belongs to a second candidate entity, and the second candidate entity is not the same entity as the first candidate entity.

[0023] In one possible design, the information of the multiple candidate cells includes identification information of each of the multiple candidate cells; sending the first information based on the information of the multiple candidate cells includes: determining to release the second candidate cell based on the identification information of each of the multiple candidate cells; and sending the first information.

[0024] In one possible design, a source entity is configured to request configuration information of multiple candidate cells for a terminal device. For example, the source entity requests configuration information of multiple candidate cells from at least one candidate entity for the terminal device, and sends RRC configuration information of the multiple candidate cells to the terminal device. The multiple candidate cells include a first candidate cell and a second candidate cell.

[0025] In one possible design, the source entity is a centralized unit CU, a source base station, or a master node MN in dual connectivity.

[0026] In one possible design, multiple candidate cells are used to perform at least one of the following: continuous conditional handover (CHO), continuous addition or change of conditional primary and secondary cells (CPAC), or continuous layer 1 / layer 2 triggered mobility (LTM).

[0027] In a second aspect, a communication method is provided. The method can be executed by a terminal device, or by a component of the terminal device, such as a processor, chip, or chip system of the terminal device, or by a logic module or software that implements all or part of the terminal device's functions. The method includes: receiving information about multiple candidate cells from a source entity; switching to a first candidate cell of a first candidate entity, where the first candidate cell is one of the multiple candidate cells; and sending first information to the first candidate entity, where the first information indicates the release of a second candidate cell, where the second candidate cell is one or more of the multiple candidate cells.

[0028] Based on this solution, the terminal device can send the first information to the first candidate entity, so that the first candidate entity can send information to the second candidate entity to instruct the release of the second candidate cell, so that the second candidate entity can promptly release the cell wireless resources reserved for the terminal device, avoiding the situation where the terminal device excessively occupies the cell wireless resources and the resources cannot be allocated to other terminal devices, thereby achieving efficient utilization of cell resources.

[0029] In one possible design, the method further includes receiving second information from a source entity, where the second information is used to indicate a condition for releasing the second candidate cell.

[0030] In one possible design, the second information includes information indicating a timer and / or a maximum number of switching times corresponding to the second candidate cell.

[0031] In one possible design, the method also includes: when the timer expires, determining to release the second candidate cell.

[0032] In one possible design, the method further includes: when the number of switches to the second candidate cell is greater than or equal to the maximum number of switches, determining to release the second candidate cell.

[0033] In one possible design, the source entity is a centralized unit CU, a source base station, or a master node MN in dual connectivity.

[0034] In one possible design, multiple candidate cells are used to perform at least one of the following: continuous conditional handover (CHO), continuous addition or change of conditional primary and secondary cells (CPAC), or continuous layer 1 / layer 2 triggered mobility (LTM).

[0035] In a third aspect, a communication method is provided, which can be executed by a source entity, or by a component of the source entity, such as a processor, chip, or chip system of the source entity, or by a logic module or software that can implement all or part of the functions of the source entity. The method includes: sending information about multiple candidate cells of a terminal device to a first candidate entity, where the first candidate entity is an entity to which the first candidate cell belongs, and the first candidate cell is one of multiple candidate cells; receiving first information from the first candidate entity, where the first information indicates the release of a second candidate cell, where the second candidate cell is one or more of the multiple candidate cells; and sending the first information to a second candidate entity, where the second candidate entity is an entity to which the second candidate cell belongs.

[0036] Based on this solution, after the source entity receives the first information from the first candidate entity, it can send information to the second candidate entity to instruct the release of the second candidate cell, so that the second candidate entity can promptly release the cell wireless resources reserved for the terminal device, avoiding the situation where the terminal device excessively occupies the cell wireless resources and the resources cannot be allocated to other terminal devices, thereby achieving efficient utilization of cell resources.

[0037] In a fourth aspect, a communication method is provided, which can be executed by a first candidate entity, or by a component of the first candidate entity, such as a processor, chip, or chip system of the first candidate entity, or by a logic module or software that can implement all or part of the functions of the first candidate entity. The method includes: receiving information about multiple candidate cells of a terminal device from a source entity; determining that the terminal device switches to a first candidate cell of the first candidate entity, where the first candidate cell is one of multiple candidate cells; sending third information to the source entity or the second candidate entity, where the third information indicates that the terminal device switches to the first candidate cell, where the second candidate entity is the entity to which the second candidate cell belongs, where the second candidate cell is one or more of the multiple candidate cells; and receiving first information from the source entity or the second candidate entity, where the first information indicates that the second candidate cell is released.

[0038] Based on this scheme, after determining that the terminal device switches to the first candidate cell of the first candidate entity, the first candidate entity can send third information to the source entity or the second candidate entity, so that the source entity or the second candidate entity knows that the terminal device switches to the first candidate cell of the first candidate entity, so that the source entity or the second candidate entity can determine the cell that needs to be released, thereby releasing the candidate cell of the terminal device in time.

[0039] In one possible design, the method also includes: sending second information to the terminal device based on the first information, where the second information indicates releasing configuration information of the second candidate cell.

[0040] In a fifth aspect, a communication method is provided. The method can be executed by a source entity, or by a component of the source entity, such as a processor, chip, or chip system of the source entity, or by a logic module or software that can implement all or part of the functions of the source entity. The method includes: sending information about multiple candidate cells to a terminal device; and sending second information to the terminal device, the second information being used to indicate a condition for releasing at least one of the multiple candidate cells.

[0041] Based on this solution, the source entity indicates the conditions for releasing candidate cells to the terminal device, allowing the terminal device to determine the candidate cells that need to be released based on the conditions, thereby enabling the terminal device to notify the candidate entity to release the candidate cells, allowing the candidate entity to release the cell radio resources reserved for the terminal device, avoiding the situation where the terminal device excessively occupies the cell radio resources and cannot allocate the resources to other terminal devices, thereby achieving efficient utilization of cell resources. In addition, the terminal device can release or deactivate the configuration information of some candidate cells, so as not to continue to evaluate whether these candidate cells can be used as target cells in the subsequent handover process, which can reduce the terminal device's judgment complexity and power consumption.

[0042] In one possible design, the second information includes information indicating a timer and / or a maximum number of switching times corresponding to each of the multiple candidate cells.

[0043] In one possible design, the method also includes: receiving first information from a first candidate entity, the first information indicating the release of the second candidate cell, the first candidate entity is the entity to which the first candidate cell belongs, the first candidate cell is the service cell of the terminal device, and the second candidate cell is one or more of the multiple candidate cells; sending information to the second candidate entity to indicate the release of the second candidate cell, the second candidate entity is the entity to which the second candidate cell belongs.

[0044] In a sixth aspect, a communication device is provided, which includes a unit or module, and the unit or module is used to execute any one of the methods described in the first to fifth aspects above.

[0045] In the seventh aspect, a communication device is provided for implementing various methods. The communication device may be the entity in the first aspect or the third to fifth aspects, or a device contained in the entity, such as a chip or a chip system; or, the communication device may be the terminal device in the second aspect, or a device contained in the terminal device, such as a chip or a chip system. The communication device includes a module, unit, or means corresponding to the implementation method, and the module, unit, or means may be implemented by hardware, software, or by executing the corresponding software implementation by hardware. The hardware or software includes one or more modules or units corresponding to the functions.

[0046] In some possible designs, the communication device may include a processing module and a transceiver module. The processing module may be configured to implement the processing functionality of any of the above aspects and any possible implementations thereof. The transceiver module may include a receiving module and a transmitting module, respectively configured to implement the receiving functionality and the transmitting functionality of any of the above aspects and any possible implementations thereof.

[0047] In some possible designs, the transceiver module may be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.

[0048] In an eighth aspect, a communication device is provided, comprising: a processor and a memory; the memory is configured to store computer instructions, and when the processor executes the instructions, the communication device performs the method described in any aspect. The communication device may be the entity described in the first aspect or any of the third to fifth aspects, or a device included in the entity, such as a chip or chip system; or the communication device may be the terminal device described in the second aspect, or a device included in the terminal device, such as a chip or chip system.

[0049] In a ninth aspect, a communication device is provided, comprising: a processor and a communication interface; the communication interface is configured to communicate with a module external to the communication device; and the processor is configured to execute a computer program or instruction to cause the communication device to perform the method described in any one of the aspects. The communication device may be the entity described in the first aspect or any of the third to fifth aspects, or a device included in the entity, such as a chip or chip system; or the communication device may be the terminal device described in the second aspect, or a device included in the terminal device, such as a chip or chip system.

[0050] In a tenth aspect, a communication device is provided, comprising: at least one processor; the processor is configured to execute a computer program or instruction stored in a memory, so that the communication device performs the method described in any aspect. The memory may be coupled to the processor, or may be independent of the processor. The communication device may be the entity described in the first aspect or any of the third to fifth aspects, or a device included in the entity, such as a chip or chip system; or the communication device may be the terminal device described in the second aspect, or a device included in the terminal device, such as a chip or chip system.

[0051] In the eleventh aspect, a computer-readable storage medium is provided, which stores a computer program or instruction. When the computer-readable storage medium is run on a communication device, the communication device can execute the method described in any one of the first to fifth aspects.

[0052] In a twelfth aspect, a computer program product comprising instructions is provided, which, when executed on a communication device, enables the communication device to execute the method described in any one of the first to fifth aspects.

[0053] In the thirteenth aspect, a communication device is provided (for example, the communication device may be a chip or a chip system), which includes a processor for implementing the functions involved in any one of the first to fifth aspects.

[0054] In some possible designs, the communication device includes a memory for storing necessary program instructions and data.

[0055] In some possible designs, when the device is a chip system, it can be composed of a chip or include a chip and other discrete devices.

[0056] It can be understood that when the communication device provided in any one of the sixth to thirteenth aspects is a chip, the sending action / function of the communication device can be understood as output information, and the receiving action / function of the communication device can be understood as input information.

[0057] Among them, the technical effects brought about by any design method in the sixth to thirteenth aspects can refer to the technical effects brought about by different design methods in the first to fifth aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] FIG1 is a schematic diagram of a switching process provided by the present application;

[0059] FIG2 is a schematic diagram of a conditional switching process provided by the present application;

[0060] FIG3 is a schematic diagram of a dual connection architecture provided by the present application;

[0061] FIG4 is a schematic diagram of a PSCell addition process provided by this application;

[0062] FIG5 is a schematic diagram of a PSCell change process provided by this application;

[0063] FIG6 is a schematic diagram of a process for adding a conditional PSCell provided in this application;

[0064] FIG7 is a schematic diagram of a conditional PSCell change process provided by this application;

[0065] FIG8 is a schematic diagram of a LTM process provided by this application;

[0066] FIG9 is a schematic diagram of the architecture of a communication system provided by the present application;

[0067] FIG10 is a schematic structural diagram of a RAN entity provided in this application;

[0068] FIG11 is a schematic structural diagram of another RAN entity provided in this application;

[0069] FIG12 is a flow chart of a communication method provided by the present application;

[0070] FIG13 is a flow chart of another communication method provided by the present application;

[0071] FIG14 is a flow chart of another communication method provided by the present application;

[0072] FIG15 is a flow chart of another communication method provided by the present application;

[0073] FIG16 is a flow chart of another communication method provided by the present application;

[0074] FIG17 is a schematic structural diagram of a communication device provided by the present application;

[0075] FIG18 is a schematic structural diagram of another communication device provided by the present application;

[0076] FIG19 is a schematic structural diagram of another communication device provided in this application. DETAILED DESCRIPTION

[0077] In the description of this application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship, for example, A / B can represent A or B; "and / or" in this application is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural.

[0078] In the description of this application, unless otherwise specified, "plurality" means two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or plural.

[0079] In addition, to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or execution order, and the words "first" and "second" do not necessarily mean different.

[0080] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner to facilitate understanding.

[0081] It will be understood that the “embodiment” mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the various embodiments throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It will be understood that in the various embodiments of the present application, the size of the sequence number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0082] It is understood that in this application, the terms "when," "when," "when," and "if" may refer to the execution of a corresponding action under certain objective circumstances. They do not specify a time limit, do not require a judgment to be made when the action is executed, and do not imply any other limitations. The phrase "execute a corresponding action under certain objective circumstances" can be understood to mean that the corresponding action will be executed as long as the objective circumstances are met, or that the corresponding action will be executed only if the objective circumstances and other circumstances are met.

[0083] It is understood that some optional features in the embodiments of the present application may, in certain scenarios, be implemented independently of other features, such as the solution on which they are currently based, to solve corresponding technical problems and achieve corresponding effects. They may also be combined with other features in certain scenarios as needed. Accordingly, the devices provided in the embodiments of the present application may also implement these features or functions accordingly, which will not be described in detail here.

[0084] In this application, unless otherwise specified, the same or similar parts between the various embodiments can refer to each other. In this application, unless otherwise specified and there is no logical conflict between the various embodiments, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. Different embodiments can be combined to form new embodiments based on their inherent logical relationships. The following description of the embodiments of this application does not constitute a limitation on the scope of protection of this application.

[0085] In order to facilitate understanding of the technical solutions of the embodiments of the present application, a brief introduction to the relevant technologies of the present application is first given as follows.

[0086] 1. Handover:

[0087] In a traditional handover process, a source base station indicates a target cell to a terminal device, and the terminal device accesses the target cell according to the instruction of the source base station.

[0088] As shown in Figure 1, the source base station first sends a Radio Resource Control (RRC) reconfiguration message to the terminal device for measurement configuration. The terminal device measures the cell according to the measurement configuration and sends a measurement report to the source base station. The source base station makes a handover decision based on the measurement report and, if it determines to handover the terminal device to the target cell of the target base station, sends a handover request message to the target base station.

[0089] After receiving the handover request message, the target base station performs admission control and sends a handover request confirmation message to the source base station if the terminal device is allowed to handover to the target cell. The handover request confirmation message may include configuration information for the terminal device to access the target cell.

[0090] After receiving the Handover Request Confirmation message, the source base station sends an RRC Reconfiguration message to the terminal device, which includes the contents of the Handover Request Confirmation message. After receiving the RRC Reconfiguration message, the terminal device initiates random access to the target cell based on the RRC Reconfiguration message. After successfully accessing the target cell, the terminal device sends an RRC Reconfiguration Complete message to the target base station.

[0091] 2. Conditional handover (CHO):

[0092] CHO is used to improve the success rate of handovers. In CHO, the source base station can configure multiple candidate cells and their corresponding handover trigger conditions to the terminal device when the source link quality is good. The terminal device then determines the target cell from the multiple candidate cells. For example, a CHO process is shown in Figure 2.

[0093] As shown in Figure 2, CHO differs from traditional handover in that, after receiving a measurement report, the source base station can send a handover request message to multiple candidate base stations to configure multiple candidate cells for the terminal device. After receiving handover request confirmation messages from multiple candidate base stations, the source base station can send an RRC reconfiguration message to the terminal device, which carries the CHO configuration. The CHO configuration includes configuration information for one or more candidate cells and their corresponding handover trigger conditions.

[0094] After receiving the RRC Reconfiguration message containing the CHO configuration, the terminal device sends an RRC Reconfiguration Complete message to the source base station. Furthermore, the terminal device evaluates the handover trigger conditions based on the CHO configuration. If the handover trigger conditions for a candidate cell are met, the terminal device selects that candidate cell as the target cell and initiates random access to the target cell. After establishing an RRC connection with the target base station, the terminal device sends an RRC Reconfiguration Complete message to the target base station. The target base station then sends a Handover Success message to the source base station.

[0095] 3. Dual connectivity (DC):

[0096] DC, also known as multi-radio dual connectivity (MR-DC), allows a single terminal device to communicate with multiple base stations. The network can leverage the resources of these multiple base stations to provide communication services to the terminal device, thereby providing high-speed transmission.

[0097] As shown in Figure 3, the base station in the DC that interacts with the core network for control plane signaling is called the master node (MN), and the other base stations are called secondary nodes (SN). For example, NG-C in Figure 3 refers to the control plane interface between the base station and the core network, Xn-C refers to the control plane interface between base stations, and Uu refers to the interface between the base station and the terminal device.

[0098] In DC, there is a primary cell (PCell) in the primary base station and a primary secondary cell (PSCell) in the secondary base station. The PCell is deployed at the primary frequency point. The PCell can be understood as the cell where the terminal device initiates initial connection establishment or connection reestablishment, or the cell indicated as the primary cell during handover. The PSCell can be understood as the cell where the terminal device initiates random access on the secondary base station, or the cell where the terminal device skips random access to initiate data transmission during the process of adding / changing the secondary base station, or the cell of the secondary base station where the terminal device initiates random access during the process of performing synchronous reconfiguration.

[0099] In a DC, a terminal device can receive services from multiple cells simultaneously under a single base station. The cell group that the MN provides services to the terminal device is called the master cell group (MCG), and the cell group that the SN provides services to the terminal device is called the secondary cell group (SCG). The MCG and SCG each include at least one cell: the MCG includes the PCell, and the SCG includes the PSCell. Cells other than the master cell and primary and secondary cells in the MCG and SCG are called secondary cells (SCells).

[0100] 4. Addition or change of PSCell:

[0101] The addition of a PSCell is triggered by the mobile network (MN). When a terminal device is single-connected (i.e., not configured with a PSCell), the mobile network (MN) triggers the addition of a PSCell. The MN can indicate the target PSCell to the terminal device, and the terminal device can initiate random access in the target PSCell. For example, the PSCell addition process is shown in Figure 4.

[0102] Referring to Figure 4, the MN can send an SN addition request message to another base station (referred to as the SN). The SN can send an SN addition request acknowledgement message to the MN, which carries the information of the target SCG (including the target PSCell) configured by the SN for the terminal device. Afterwards, the source MN sends the target SCG information to the terminal device through an RRC reconfiguration message. After receiving the target SCG information, the terminal device can initiate random access in the target PSCell and send an RRC reconfiguration completion message to the MN. In addition, the MN also sends an SN RRC reconfiguration completion message to the SN.

[0103] A PSCell change can be triggered by either the mobile network (MN) or the source network (SN). A PSCell change can be caused by the movement of a terminal device. The network can indicate a target PSCell to the terminal device, and the terminal device can switch from the current PSCell to the target PSCell based on the network's instructions. An exemplary PSCell change process is shown in Figure 5.

[0104] Referring to Figure 5 , the steps corresponding to the solid line represent the PSCell addition process triggered by the MN, and the steps corresponding to the solid and dashed lines represent the PSCell change process triggered by the MN. The steps corresponding to the solid and dotted lines represent the PSCell change process triggered by the source SN. As shown in Figure 5 , the difference between the MN-triggered PSCell change process and the PSCell addition process is that after the MN sends an SN Add Request message to the target SN, the MN needs to send an SN Release Request message to the source SN to inform the source SN to stop data transmission with the terminal device.

[0105] As shown in Figure 5, based on the MN-triggered PSCell addition process, the source SN-triggered PSCell change process adds the following steps: After the source SN prepares the target PSCell for the terminal device, the source SN needs to send an SN change request (SN change required) message to the MN so that the MN can determine the target PSCell to be requested. In addition, after receiving the RRC reconfiguration completion message sent by the terminal device, the MN sends an SN change confirmation (SN change confirm) message to the source SN to cause the source SN to stop data transmission with the terminal device.

[0106] 5. Conditional PSCell addition / change (CPAC):

[0107] In the CPAC mechanism, the mobile network (MN) or source network (SN) can prepare multiple candidate PSCells and their corresponding execution conditions for the terminal device in advance. The network can then send a CPAC configuration to the terminal device, including configuration information for the multiple candidate PSCells and their corresponding execution conditions. The terminal device then determines the target PSCell from the multiple candidate PSCells and accesses it. An example of a conditional PSCell addition (CPA) process is shown in Figure 6.

[0108] Referring to Figure 6, the difference between CPA and the basic PSCell addition process shown in Figure 4 is that the MN can send an SN addition request message to one or more candidate SNs. After receiving the SN addition request confirmation message from the candidate SN, the RRC reconfiguration message sent by the MN to the terminal device may include CPAC configuration information, and the CPAC configuration information may include the configuration information of at least one candidate PSCell and its corresponding execution trigger condition. After receiving the CPAC configuration, the terminal device will not immediately add any candidate PSCell, but will continue to determine whether there is a candidate PSCell that meets the execution trigger condition.

[0109] When the terminal device determines that a candidate PSCell meets its corresponding execution trigger condition, the terminal device uses the candidate PSCell as the target PSCell and sends an RRC reconfiguration completion message indicating the target PSCell to the MN. In the RRC reconfiguration completion message, the target PSCell can be implicitly indicated by indicating the configuration identification information corresponding to the target PSCell. The terminal device initiates random access in the target PSCell. After receiving the RRC reconfiguration completion message indicating the target PSCell, the MN sends an SN RRC reconfiguration completion message to the target SN and sends an SN release request message to other candidate SNs.

[0110] An exemplary process for conditional PSCell addition (CPC) is shown in FIG7 . The steps corresponding to the solid and dashed lines are the CPC process triggered by the MN, while the steps corresponding to the solid and dotted lines are the CPC process triggered by the source SN.

[0111] Referring to Figure 7 , based on the MN-triggered CPA process shown in Figure 6 , the additional steps of the MN-triggered CPC process are as follows: After receiving the RRC reconfiguration completion message sent by the terminal device, the MN can send an Xn-U address indication to the source SN to inform the source SN that CPAC has been configured for the terminal device so that the source SN can perform early data transfer to the candidate SN.

[0112] Referring to Figure 7, based on the CPA process triggered by the MN shown in Figure 6, the CPC process triggered by the source SN adds the following steps: the source SN needs to send an SN change requirement (SN change required) message to the MN so that the MN requests to add a candidate PSCell. In addition, the MN notifies the source SN of the candidate PSCell information accepted by the candidate SN through an SN modification request (SN modification request) before sending the CPAC configuration information to the terminal device or through an SN change confirmation (SN change conform) after sending the CPAC configuration information. The source SN can initiate a process to update the configuration information of the candidate PSCell for the terminal device (including one or more of the PSCell cell, execution trigger conditions, and measurement configuration).

[0113] 6. L1 / L2 triggered mobility (LTM):

[0114] In the LTM mechanism, the network side sends LTM configuration information to the terminal device in advance. The LTM configuration information includes the configuration information of one or more candidate cells, and also includes L1 measurement control information. The terminal device saves the LTM configuration information and reports the layer 1 measurement report of the candidate cell to the network side. The network side determines the target cell from multiple candidate cells based on the layer 1 measurement report, and sends an LTM command to the terminal device to indicate the target cell. The LTM command is sent to the terminal device through the media access control (MAC) control element (CE) of L2. Based on the LTM command, the terminal device applies the configuration information of the target cell to access the target cell. The way the terminal device accesses the target cell can be based on random access or random access-free, that is, the terminal device performs uplink transmission / downlink reception based on the acquired effective timing advance (TA) and beam information of the target cell.

[0115] Exemplarily, a LTM process within a centralized unit (CU) (intra-CU) or between CUs (inter-CU) is shown in FIG8 .

[0116] Referring to Figure 8, the source CU (CU1) can obtain the configuration information of multiple candidate cells and send a candidate cell pre-configuration message to the terminal device through the source distributed unit (DU) (DU1), which includes the configuration information of multiple candidate cells. For example, in intra-CU LTM, the source CU can request the configuration information of the candidate cell from the candidate DU managed by the source CU (not shown in Figure 8); in inter-CU LTM, the source CU can request the configuration information of the candidate cell from the candidate DU (DU2) managed by the candidate CU through the candidate CU (CU2).

[0117] After receiving the configuration information of the candidate cell, the terminal device can perform measurements and send the layer 1 measurement results to the source DU. The source DU can determine the target cell based on the layer 1 measurement results and send an LTM command to the terminal device. The LTM command can indicate the target cell. In addition, the source DU can send an LTM notification to the source CU to notify the initiation of the LTM command and indicate the target cell. After receiving the LTM command, the terminal device can access the target DU (that is, the DU to which the target cell belongs). After the terminal device accesses the target DU, the target DU can send an access success message to the target CU. In intra-CU LTM, the source CU and the target CU are the same CU. In inter-CU LTM, the source CU and the target CU are not the same CU.

[0118] 7. Continuous LTM, continuous CHO, continuous CPAC:

[0119] In the continuous LTM mechanism, after the terminal device accesses the target cell, it still saves the configuration information of the candidate cell, continues to measure the candidate cell, and sends the L1 measurement results to the current serving DU so that the current serving DU can determine the target cell for the next handover.

[0120] In the continuous CPAC mechanism, after a terminal device accesses a candidate PSCell (i.e., the target PSCell) that meets the execution trigger conditions, it retains the CPAC configuration information from the mobile network (MN) to continue adding or changing PSCells. The network side does not need to send an RRC reconfiguration message to the terminal device again to configure one or more candidate PSCells for subsequent PSCell additions or changes.

[0121] In the continuous CHO mechanism, after the terminal device switches to a candidate cell (i.e., the target cell) that meets the handover trigger conditions, it still retains the CHO configuration information from the source base station to continue the conditional handover. The network side does not need to send an RRC reconfiguration message to the terminal device again to configure one or more candidate cells for subsequent cell handovers.

[0122] In other words, in the continuous LTM, CPAC, and CHO mechanisms, after accessing the target cell, the terminal device may still retain the previous candidate cell configuration and continue subsequent handovers based on this candidate cell configuration. However, there is currently no solution for how to release these candidate cells.

[0123] Based on this, the present application provides a communication method, in which the service entity, source entity or candidate entity of the terminal device can instruct the terminal device and the candidate entity to release part or all of the candidate cells after determining that the terminal device has accessed the target cell, so that the terminal device can save a suitable set of candidate cells, reducing the complexity of the terminal device's judgment implementation. In addition, the candidate entity can promptly release the cell wireless resources reserved for the terminal device, avoiding the situation where the terminal device excessively occupies the cell wireless resources and the resources cannot be allocated to other terminal devices, thereby achieving efficient utilization of cell resources.

[0124] The technical solution provided in this application can be used in various communication systems, which may be a third generation partnership project (3GPP) communication system, for example, a fourth generation (4G) long term evolution (LTE) system, a fifth generation (5G) new radio (NR) system, a vehicle to everything (V2X) system, a system of hybrid networking of LTE and NR, or a device to device (D2D) system, a machine to machine (M2M) communication system, the Internet of Things (IoT), a non-terrestrial network (NTN), and other next generation communication systems. Alternatively, the communication system may also be a non-3GPP communication system, without limitation.

[0125] Among them, the above-mentioned communication system applicable to the present application is only an example, and the communication system applicable to the present application is not limited to this. It is uniformly described here and will not be repeated below.

[0126] FIG9 shows an exemplary communication system provided herein. The communication system includes a radio access network (RAN) 900. RAN 900 includes at least one RAN entity (e.g., 910a and 910b in FIG9 , collectively referred to as 910) and at least one terminal device (e.g., 920a-920j in FIG9 , collectively referred to as 920). Terminal device 920 is wirelessly connected to at least one RAN entity 910.

[0127] Optionally, the RAN may also include other RAN entities, such as wireless relay equipment and / or wireless backhaul equipment (not shown in FIG. 9 ). The communication system may also include a core network (CN). The RAN entity 910 is connected to the core network via wireless or wired communication. The core network equipment in the core network and the RAN entity 910 in the RAN 900 may be different physical devices, or they may be the same physical device that integrates the core network logical functions and the radio access network logical functions.

[0128] The RAN 900 may be a 3GPP-related cellular system, such as a 4G or 5G mobile communication system, or a future-oriented evolutionary system (such as a sixth generation (6G) mobile communication system). The RAN 900 may also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system, or a communication system that integrates two or more of the above systems.

[0129] RAN entity 910, sometimes also referred to as access network equipment, RAN node, access entity, or access node, constitutes part of a communication system and facilitates wireless access for terminal devices. Multiple RAN entities 910 in a communication system can be of the same type or different types.

[0130] In some scenarios, the roles of the RAN entity 910 and the terminal device 920 are relative. For example, in Figure 9 , the network element 920i can be a helicopter or drone, which can be configured as a mobile base station. For the terminal device 920j that accesses the RAN 100 through the network element 920i, the network element 920i is a base station; however, for the RAN entity 910a, the network element 920i is a terminal device. The RAN entity 910 and the terminal device 920 are sometimes referred to as communication devices. For example, in Figure 9 , the network elements 910a and 910b can be understood as communication devices with base station functions, and the network elements 920a-920j can be understood as communication devices with terminal functions.

[0131] In one possible scenario, a RAN entity may be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access entity in a WiFi system. A RAN entity may be a macro base station (such as 910a in Figure 9 ), a micro base station or an indoor station (such as 910b in Figure 9 ), a relay entity or a donor entity, or a wireless controller in a CRAN scenario. Optionally, a RAN entity may also be a server, a wearable device, a vehicle, or an onboard device. For example, a RAN entity in vehicle-to-everything (V2X) technology may be a road side unit (RSU).

[0132] In another possible scenario, multiple RAN entities collaborate to assist terminal devices in achieving wireless access, and different RAN entities respectively implement part of the functions of the base station. For example, the RAN entity can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be set up separately, or they can be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0133] The CU and DU split the base station's protocol layers, centrally controlling some protocol layer functions in the CU and distributing some or all of the remaining protocol layer functions in the DU. The CU can centrally control the DU. As an implementation, as shown in Figure 10, the CU deploys the radio resource control (RRC), packet data convergence protocol (PDCP), and service data adaptation protocol (SDAP) layers of the protocol stack; the DU deploys the radio link control (RLC), media access control (MAC), and physical layers (PHY) of the protocol stack. Thus, the CU has the processing capabilities of the RRC, PDCP, and SDAP layers. The DU has the processing capabilities of the RLC, MAC, and PHY layers. Furthermore, Figure 10 (a) shows a scenario where the CU-CP and CU-UP are separate, with PDCP-C referring to the PDCP control plane and PDCP-U referring to the PDCP data plane. Figure 10 (b) shows a scenario where the CU-CP and CU-UP are co-located. It is understandable that the above functional division is only an example and does not constitute a limitation on CU and DU.

[0134] In one possible scenario, the DU has high-level (close to the MAC layer) functions of the PHY layer, such as forward error correction (FEC) encoding / decoding, scrambling / descrambling, or modulation / demodulation. The RU has low-level functions of the PHY layer and radio frequency functions. Exemplarily, the low-level functions of the PHY layer include at least one of the following: fast Fourier transform (FFT), inverse fast Fourier transform (iFFT), digital beamforming, or physical random access channel (PRACH) extraction and filtering.

[0135] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meanings. For example, as shown in Figure 11, in the ORAN system, CU may also be called O-CU (Open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the sake of convenience, this application uses CU, CU-CP, CU-UP, DU, and RU as examples for description.

[0136] In one possible scenario, all or part of the functions of the RAN entity in this application may also be implemented through software functions running on hardware, or through virtualized functions instantiated on a platform (e.g., a cloud platform). Alternatively, the RAN entity in this application may also be a logical entity, logical module, or software that can implement all or part of the RAN entity functions. Alternatively, the RAN entity in this application may be implemented through a software module, a hardware module, or a combination of a software module and a hardware module.

[0137] The terminal device 920 may refer to a user-side device with wireless transceiver functions. The terminal device 920 may also be referred to as user equipment (UE), terminal, access terminal device, user unit, user station, mobile station (MS), remote station, remote terminal device, mobile terminal device (MT), user terminal device, wireless communication device, user agent or user device, etc. The terminal device may be, for example, an IoT, V2X, D2D, M2M, 5G network, or a terminal device in a future evolved public land mobile network (PLMN). The terminal device may be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it may also be deployed on water (such as a ship); it may also be deployed in the air (such as an airplane, balloon, or satellite).

[0138] Exemplarily, the terminal device may be a drone, an IoT device (e.g., a sensor, an electricity meter, a water meter, etc.), a V2X device, a station (ST) in a wireless local area network (WLAN), a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA) device, a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device (also referred to as a wearable smart device), a tablet computer or a computer with wireless transceiver function, a virtual reality (VR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical care, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, a smart home, or a similar device. The present application does not specifically limit the terminal devices to mobile or fixed devices.

[0139] The following will describe the communication method provided in the embodiment of the present application in detail with reference to the accompanying drawings, taking the interaction between the RAN entity and the terminal device shown in FIG9 as an example.

[0140] It is understood that in the embodiments of the present application, the RAN entity or terminal device may perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples, and the embodiments of the present application may also perform other operations or variations of various operations. In addition, the various steps may be performed in a different order than those presented in the embodiments of the present application, and it is possible that not all operations in the embodiments of the present application need to be performed.

[0141] It should be noted that the message names between the devices or the names of the parameters in the messages in the following embodiments of the present application are only examples. Other names may be used in specific implementations, and the embodiments of the present application do not specifically limit this.

[0142] It should be noted that, for the convenience of description, the RAN entity is referred to as the entity in the following embodiments of the present application. That is, the entity in the following embodiments of the present application can be understood as the RAN entity.

[0143] FIG12 is a flow chart of a communication method provided in an embodiment of the present application, which includes the following steps:

[0144] S1201. The first entity obtains information of multiple candidate cells of the terminal device.

[0145] In one possible implementation, the first entity may be a service entity, a source entity, or a candidate entity (not a service entity). It should be noted that in the embodiments of the present application, it is assumed that the terminal device first accesses the source entity, and subsequently the terminal device may access other entities, for example, by random access or random access-free access. Unless otherwise specified, the service entity in the embodiments of the present application refers to the other entity that the terminal device subsequently accesses.

[0146] Optionally, the source entity can be understood as an entity that requests the configuration information of the multiple candidate cells, or in other words, the source entity is used to request the configuration information of the multiple candidate cells for the terminal device. For example, the source entity can request the configuration information of multiple candidate cells from at least one candidate entity for the terminal device, and after receiving the configuration information of the candidate cells, send the RRC configuration information of the multiple candidate cells to the terminal device. Exemplarily, the source entity can be a CU, such as a CU in a continuous intra-CU LTM scenario or a source CU in a continuous inter-CU LTM scenario; or, the source entity can be a source base station, such as a source base station in a continuous CHO scenario; or, the source entity can be an MN, such as an MN in a continuous CPAC scenario, the triggering node of CPAC can be an MN or a source SN, and the MN requests multiple candidate cells for the terminal device.

[0147] Optionally, among the multiple candidate cells, the entity to which each candidate cell belongs can be called a candidate entity. Exemplarily, when the source entity is a CU in a continuous intra-CU LTM scenario, the candidate entity can be a DU managed by the CU; when the source entity is a source CU in a continuous inter-CU LTM scenario, the candidate entity can be another CU (referred to as a candidate CU). When the source entity is a source base station, the candidate entity can be another base station (referred to as a candidate base station). When the source entity is an MN, the candidate entity can be an SN (referred to as a candidate SN).

[0148] It should be noted that the names of candidate cells and candidate entities may change according to changes in the execution process. For example, after the terminal device determines a candidate cell among multiple candidate cells as the target cell, the candidate cell can be called the target cell, and accordingly, the entity to which the candidate cell belongs can be called the target entity. After the terminal device accesses or switches to the target cell, the target cell can be called the service cell, and accordingly, the entity to which the cell belongs can be called the service entity. That is, a candidate cell can be called a candidate cell, a target cell, and a service cell before, during, and after the switching; accordingly, the candidate entity to which the candidate cell belongs can be called a candidate entity, a target entity, and a service entity before, during, and after the switching.

[0149] For example, taking multiple candidate cells including candidate cell 1, candidate cell 2, and candidate cell 3, and the three candidate cells respectively belonging to candidate entity 1, candidate entity 2, and candidate entity 3 as an example, assuming that the terminal device determines candidate cell 1 as the target cell, then candidate cell 1 can be respectively referred to as the candidate cell, target cell, and serving cell before, during, and after the handover, and candidate entity 1 can be respectively referred to as the candidate entity, target entity, and serving entity before, during, and after the handover. Candidate cell 2 and candidate cell 3 are both candidate cells throughout the entire process, and candidate entity 2 and candidate entity 3 are both candidate entities throughout the entire process.

[0150] Optionally, when the first entity is a serving entity, the cell serving the terminal device may be a candidate cell (also referred to as a target cell) to which the terminal device accesses or switches based on information of multiple candidate cells. For example, based on the above example, taking the terminal device accessing candidate cell 1 as an example, the first entity is candidate entity 1.

[0151] Optionally, when the first entity is a candidate entity, the candidate entity is not a serving entity. For example, based on the above example, taking the terminal device accessing candidate cell 1 as an example, the first entity may be candidate entity 2 or candidate entity 3.

[0152] Optionally, the multiple candidate cells may be used for at least one of continuous CHO, continuous CPAC, or continuous LTM.

[0153] Optionally, the information of multiple candidate cells may include identification information of each of the multiple candidate cells. Exemplarily, the identification information of the candidate cell may be one or more of the candidate cell's cell global identifier (CGI), physical cell identifier (PCI) and frequency, PCI, cell identifier (cell ID), non-public network identifier (NPN ID), non-terrestrial network identifier (NTN ID), cell configuration identification information, or other cell identifiers. The CGI may include a PLMN identifier and a cell ID, and may further include a tracking area code (TAC).

[0154] In addition, the first entity may also obtain one or more of the identification information assigned by the source entity to the terminal device, the identification information of the source entity, and the identification information assigned by the candidate entity to the terminal device. The one or more pieces of information may be used to indicate that the candidate cell is a candidate cell for the terminal device.

[0155] Optionally, when the first entity is a source entity, the source entity may determine at least one initial candidate cell for the terminal device based on the measurement report reported by the terminal device, and send a request message to the candidate entity to request the configuration information of the initial candidate cell. The request message may include identification information of the initial candidate cell. Accordingly, the candidate entity may send a response message, which includes the configuration information of the initial candidate cell and may also include identification information of the initial candidate cell. Based on this, if the candidate entity to which an initial candidate cell belongs returns the configuration information of the initial candidate cell, the source entity can determine the initial candidate cell as a true candidate cell, thereby determining the identification information of the candidate cell.

[0156] When the first entity is a serving entity or a candidate entity, the first entity obtaining information about multiple candidate cells of the terminal device may include: the first entity receiving information about the multiple candidate cells from a source entity. The manner in which the source entity obtains information about the multiple candidate cells can be referred to in the description in the previous paragraph.

[0157] S1202: The first entity determines that the terminal device is to be handed over to a first candidate cell of the first candidate entity, where the first candidate cell is one of multiple candidate cells.

[0158] Optionally, the terminal device switches to the first candidate cell of the first candidate entity, which can also be understood as: the terminal device accesses the first candidate entity, or accesses the first candidate cell, or accesses the first cell of the first candidate entity, which can be replaced with each other.

[0159] Optionally, when the terminal device switches to the first candidate cell of the first candidate entity, the first candidate cell may also be referred to as the target cell or service cell, and the first candidate entity may also be referred to as the target entity or service entity. Please refer to the relevant instructions on the cell and entity names in the above step S1201, which will not be repeated here.

[0160] As a possible implementation, when the first entity is a service entity (i.e., the first candidate entity), after the terminal device successfully switches / accesses the first candidate cell, the first candidate entity can determine that the terminal device switches / accesses the first candidate cell of the first candidate entity.

[0161] As another possible implementation, when the first entity is the source entity or candidate entity, after the terminal device successfully switches to / accesses the first candidate cell, the first candidate entity may send third information to the first entity, instructing the terminal device to switch to the first candidate cell. Thus, the first entity determining that the terminal device has switched to the first candidate cell of the first candidate entity may include: the first entity receiving the third information from the first candidate entity. Upon receiving the third information, the first entity learns that the terminal device has switched to the first candidate cell of the first candidate entity.

[0162] S1203. The first entity sends first information based on information of multiple candidate cells.

[0163] The first information indicates that the second candidate cell is released. Exemplarily, the first information may indicate information about the released second candidate cell. The information about the candidate cell includes identification information of the candidate cell.

[0164] The second candidate cell is one or more of the multiple candidate cells, or can also be expressed as the second candidate cell is all or part of the multiple candidate cells. Exemplarily, the first entity can determine the second candidate cell from the multiple candidate cells.

[0165] Optionally, the second candidate cell may be one or more candidate cells under the first entity, or may be one or more candidate cells under at least one other candidate entity other than the first entity, or may include one or more candidate cells under the first entity and one or more candidate cells under at least one other candidate entity.

[0166] Optionally, the second candidate cell may not include the first candidate cell, that is, the released candidate cell does not include the first candidate cell; or the second candidate cell may include the first candidate cell, that is, the released candidate cell includes the first candidate cell.

[0167] Optionally, the second candidate cell belongs to a second candidate entity. The second candidate entity and the first candidate entity may be the same entity or may not be the same entity. In the following embodiments of the present application, the second candidate entity and the first candidate entity are not the same entity as an example for description.

[0168] Optionally, the first information indicates releasing the second candidate cell, which can also be understood as: the first information indicates releasing or deactivating the resources of the second candidate cell allocated to the terminal device.

[0169] Optionally, after determining that the terminal device switches to the first candidate cell, the first entity may determine the serving entity of the terminal device to determine the second candidate cell that the terminal device needs to release under the serving entity, thereby sending the first information.

[0170] Optionally, when the first entity is a serving entity, the first entity may send the first information to the source entity or the second candidate entity. When the first entity is a source entity, the first entity may send the first information to the serving entity or the second candidate entity. When the first entity is a candidate entity, the first entity may send the first information to the serving entity or the source entity.

[0171] Optionally, the first information may include at least one of the following: identification information of the second candidate cell, identification information assigned by the source entity to the terminal device, identification information assigned by the second candidate entity to the terminal device, or identification information of the source entity. Exemplarily, the identification information assigned by the source entity to the terminal device and the identification information assigned by the second candidate entity to the terminal device can be used by the recipient of the first information to identify the terminal device. Combined with the identification information of the second candidate cell, the recipient of the first information can identify the resources of the second candidate cell allocated to the terminal device.

[0172] Optionally, when the information of the multiple candidate cells includes identification information of each of the multiple candidate cells, the first entity sending the first information based on the information of the multiple candidate cells may include: the first entity determining to release the second candidate cell based on the identification information of each of the multiple candidate cells, such as identifying multiple candidate cells based on the identification information of each of the multiple candidate cells, and then determining the second candidate cell from the multiple candidate cells. After determining the second candidate cell, the first entity sends the first information to indicate the release of the second candidate cell.

[0173] In the embodiments of the present application, the implementation related to the second candidate cell is applicable to one or more candidate cells instructed to be released by the first entity, or is applicable to one or more candidate cells other than the first candidate cell instructed to be released. They are uniformly described here and will not be repeated in subsequent embodiments.

[0174] In one possible scenario, the serving entity or the source entity may send second information to the terminal device. The second information indicates configuration information for releasing the second candidate cell. After receiving the second information, the terminal device may learn the candidate cell to be released based on the second information, thereby releasing the second candidate cell.

[0175] As a possible implementation, when the first entity is a serving entity, the serving entity may send the second information to the terminal device after determining the second candidate cell from multiple candidate cells. When the first entity is a source entity or a second candidate entity, the first entity may send the second information to the terminal device after receiving the first information from the source entity or the second candidate entity.

[0176] As another possible implementation, the source entity may send the second information to the terminal device when configuring the candidate cell to the terminal device. For example, the source entity sends the configuration information of the first candidate cell to the terminal device, and the configuration information of the first candidate cell includes the second information. Exemplarily, when the source entity requests the configuration information of the first candidate cell from the second candidate entity, the second candidate entity may carry the identification information of the cell to be released (such as the second candidate cell) corresponding to the first candidate cell in the configuration information of the first candidate cell, or carry the second information. When the source entity subsequently sends the configuration information of the first candidate cell to the terminal device, the second information may be carried in the configuration information of the first candidate cell. After the subsequent terminal device applies the configuration information of the first candidate cell to access the first candidate cell, it can be informed that the configuration information of the second candidate cell needs to be released.

[0177] Based on this solution, a first entity (i.e., a service entity, source entity, or candidate entity of a terminal device) can send a first message to instruct the release of one or more candidate cells after determining that the terminal device has accessed a first candidate cell. When the first entity sends the first message to the candidate entity to which the candidate cell to be released belongs, the candidate entity can promptly release the cell radio resources allocated to the terminal device, thereby avoiding the situation where the terminal device excessively occupies the cell radio resources and cannot allocate the resources to other terminal devices, thereby achieving efficient utilization of cell resources.

[0178] The above is an overall description of the communication method provided by the present application. The following describes the above method in detail, taking the first entity as a serving entity, a source entity, and a candidate entity as examples.

[0179] When the first entity is a serving entity and the serving entity is a first candidate entity, as shown in FIG13 , the communication method provided by the present application includes the following steps:

[0180] S1301. The source entity obtains configuration information of multiple candidate cells of the terminal device.

[0181] Optionally, before step S1301, the source entity may receive a measurement report from the terminal device, such as a layer 3 (L3) measurement report, and determine one or more candidate cells for the terminal device based on the measurement report, and initiate a handover procedure, thereby executing step S1301. The handover procedure initiated by the terminal device may be used to switch between a primary cell and / or a primary / secondary cell.

[0182] Exemplarily, the source entity may determine N candidate cells (i.e., initial candidate cells) based on the measurement report reported by the terminal device, where N is an integer greater than or equal to 1. The N candidate cells may belong to M candidate entities, where M is a positive integer less than or equal to N. When M is less than N, it indicates that at least two of the N candidate cells belong to the same candidate entity.

[0183] For the convenience of description, in the following embodiments of the present application, the N candidate cells are collectively referred to as candidate cell set 1, that is, the candidate cell set 1 is composed of the N candidate cells.

[0184] Taking a candidate cell in the candidate cell set 1 as an example, after the source entity determines the candidate cell for the terminal device, it can request the configuration information of the candidate cell from the candidate entity for the terminal device. For example, the source entity can send a request message to the candidate entity to request the configuration information of the candidate cell, and the configuration information of the candidate cell can also be referred to as the RRC configuration information of the candidate cell. The configuration information of the candidate cell can be used for the terminal device to access the candidate cell, for example, including the identification information of the candidate cell and the configuration parameter information of the candidate cell. The request message may include the identification information of the terminal device and the identification information of the candidate cell. The identification information of the terminal device can be an inter-station (Xn) application protocol (AP) identifier assigned by the source entity to the terminal device, that is, an XnAP ID. The identification information of the candidate cell can refer to the relevant instructions in the above step S1201 and will not be repeated here.

[0185] Exemplarily, the configuration parameter information of the candidate cell may include but is not limited to at least one of the following: a cell radio network temporary identifier (C-RNTI) allocated by the candidate cell to the terminal device, random access channel (RACH) resources, security-related algorithms of the candidate cell, etc.

[0186] After receiving the request from the source entity, if the candidate entity allows the terminal device to access the candidate cell or agrees to prepare the candidate cell for the terminal device, the candidate entity sends a response message to the source entity. The response message may include the configuration information of the candidate cell and the identification information assigned by the candidate entity to the terminal device, such as the XnAP ID assigned by the candidate entity to the terminal device. After receiving the configuration information of the candidate cell, the source entity may not parse the configuration information and directly transmit the configuration information to the terminal device.

[0187] Exemplarily, when a source entity requests configuration information for multiple candidate cells in a single request message, the response message sent by the candidate entity may include the identifier of the candidate cell and the configuration information of the candidate cell, or a set / list of candidate cell identifiers and a corresponding set / list of candidate cell configurations. When a source entity requests configuration information for a single candidate cell in a single request message, the response message sent by the candidate entity may include the configuration information. In this case, the configuration information in the response message is the configuration information of the candidate cell requested by the source entity.

[0188] After the candidate entity receives the request message from the source entity, if the candidate entity does not allow the terminal device to access the candidate cell or does not agree to prepare the candidate cell for the terminal device, the candidate entity does not send the configuration information of the candidate cell to the source entity.

[0189] Therefore, the number of candidate cells whose configuration information the source entity obtains may be less than or equal to N. That is, in step S1301, the source entity obtains the configuration information of some or all candidate cells in candidate cell set 1. For the convenience of description, in the following embodiments of this application, the one or more candidate cells whose configuration information the source entity obtains are collectively referred to as candidate cell set 2, and candidate cell set 2 is a subset of candidate cell set 1. The candidate cells in candidate cell set 2 can also be understood as candidate cells prepared by the candidate entity for the terminal device.

[0190] Optionally, in a continuous CHO scenario, the request message may be a handover request message, and the corresponding response message may be a handover request response message. In a continuous CPAC scenario, the request message may be a SN addition request message, and the corresponding response message may be a SN addition request confirmation message. In a continuous LTM scenario, the request message may be a message requesting a candidate cell, and the corresponding response message may be a message responding to the candidate cell request.

[0191] Optionally, the request message sent by the source entity may be at a cell granularity, i.e., the source entity may send a request message for each of the N candidate cells. Alternatively, the request message may be at a candidate entity granularity, i.e., the source entity may send a request message for each of the M candidate entities. In this scenario, if at least two candidate cells belong to the same candidate entity, the source entity sends a request message to the candidate entity, and the request message is used to request configuration information of the at least two candidate cells.

[0192] Optionally, for a candidate entity that receives a request message, the response message sent by the candidate entity may be at a cell granularity or a candidate entity granularity. Please refer to the relevant description of the request message and will not be repeated here.

[0193] For the sake of convenience, in the embodiment of the present application, the candidate cell set 2 includes a first candidate cell and a second candidate cell, that is, the source entity obtains the configuration information of the first candidate cell and the second candidate cell of the terminal device, and the first candidate cell belongs to the first candidate entity and the second candidate cell belongs to the second candidate entity.

[0194] In one possible implementation, the configuration information of the candidate cell sent by the candidate entity to the source entity may include identification information of the cell to be released corresponding to the candidate cell. After the terminal device subsequently accesses the candidate cell using the configuration information of the candidate cell, the cell to be released may be released. For example, the cell to be released corresponding to a candidate cell may not be a neighboring cell of the candidate cell. In other words, when configuring the candidate cell to the terminal device, the candidate entity may pre-configure the cell to be released corresponding to the candidate cell, that is, which cells should be released after the terminal device accesses the candidate cell.

[0195] Optionally, the configuration information of the first candidate cell sent by the first candidate entity to the source entity may include information of a second candidate cell, where the second candidate cell is the cell to be released corresponding to the first candidate cell. The configuration information of other candidate cells in the candidate cell set 2 may also include identification information of the cell to be released corresponding to the candidate cell, and the cells to be released corresponding to different candidate cells may be different.

[0196] S1302: The source entity sends configuration information of multiple candidate cells (candidate cells in candidate cell set 2) to the terminal device. Correspondingly, the terminal device receives the configuration information of the multiple candidate cells from the source entity.

[0197] Optionally, the source entity may send an RRC reconfiguration message to the terminal device, carrying the configuration information of the multiple candidate cells in the RRC reconfiguration message. In addition, in a continuous CHO or continuous CPAC scenario, the source entity may also send a handover trigger condition or execution trigger condition corresponding to each of the multiple candidate cells to the terminal device.

[0198] S1303. The source entity sends information about at least one candidate cell of a terminal device to at least one candidate entity. Correspondingly, the candidate entity receives information about at least one candidate cell of the terminal device from the source entity. For ease of description, in the following embodiments of this application, the at least one candidate cell is collectively referred to as candidate cell set 3, i.e., candidate cell set 3 consists of the at least one candidate cell.

[0199] In a first possible implementation, candidate cell set 3 is the same as candidate cell set 2. In addition, after step S1301, the source entity may send information of candidate cell set 2 to candidate entities to which at least one candidate cell in candidate cell set 2 belongs.

[0200] For example, taking the case where the candidate cell set 2 includes a first candidate cell and a second candidate cell, the first candidate cell belongs to a first candidate entity, and the second candidate cell belongs to a second candidate entity, in step S1303, the source entity may send information about the first candidate cell and information about the second candidate cell to the first candidate entity, and send information about the first candidate cell and the second candidate cell to the second candidate entity.

[0201] In a second possible implementation, candidate cell set 3 includes some candidate cells in candidate cell set 2. In addition, after step S1301, the source entity may send information about some candidate cells in candidate set 2 to candidate entities to which at least one candidate cell in candidate cell set 2 belongs, where the some candidate cells are cells of other candidate entities except the receiving candidate entity.

[0202] Exemplarily, taking the case where the candidate cell set 2 includes a first candidate cell and a second candidate cell, the first candidate cell belongs to the first candidate entity, and the second candidate cell belongs to the second candidate entity as an example, in step S1303, since the second candidate cell is not the cell of the first candidate entity, the source entity can send information about the second candidate cell to the first candidate entity, and since the first candidate cell is not the cell of the second candidate entity, the source entity can send information about the first candidate cell to the second candidate entity. In this scenario, since the first candidate cell is the cell of the first candidate entity, and the first candidate entity sent the configuration information of the first candidate cell to the source entity in step S1301, the first candidate entity can determine that the candidate cells of the terminal device include the first candidate cell and the second candidate cell. Similarly, the second candidate entity can determine that the candidate cells of the terminal device include the first candidate cell and the second candidate cell.

[0203] It should be noted that in the first and second possible implementations described above, there is no strict order for step S1302 and step S1303. Step S1302 may be performed first, followed by step S1303; or step S1303 may be performed first, followed by step S1302; or step S1302 and step S1303 may be performed simultaneously, and this application does not impose any specific restrictions on this.

[0204] In a third possible implementation, in a continuous CPAC scenario, after step S1302, if the triggering condition of a candidate cell (such as the first candidate cell) is met, the terminal device can indicate the identification information of the first candidate cell to the MN (source entity), and the MN (source entity) sends the information of each candidate cell in the candidate cell set 3 to the first candidate entity (i.e., candidate SN, also called target entity, also called service entity after the terminal device accesses) through the S1303 step. In this scenario, the candidate cell set 3 and the candidate cell set 2 may be the same, or the candidate cell set 3 includes some candidate cells in the candidate cell set 2, and these some candidate cells are cells of other candidate entities except the service entity.

[0205] In the first, second and third possible implementations described above, it can be considered that there is a separate step S1303, that is, step S1301 and step S1303 are two independent steps.

[0206] In a fourth possible implementation, step S1303 and step S1301 may be the same step, i.e., it may be considered that there is no separate step S1303. For example, when the source entity requests candidate cells from the candidate entity in step S1301, it may send information about N candidate cells in candidate cell set 1 to the candidate entity. In this case, candidate cell set 3 may be considered the same as candidate cell set 1. Alternatively, the source entity may send information about some candidate cells in candidate cell set 1 to the candidate entity, where these some candidate cells are the candidate cells of the corresponding receiving candidate entity. In this case, candidate cell set 3 may be considered to include some candidate cells in candidate cell set 1.

[0207] For example, taking the case where candidate cell set 1 includes a first candidate cell and a second candidate cell, and the first candidate cell belongs to a first candidate entity and the second candidate cell belongs to a second candidate entity, the source entity may send information about the first candidate cell and the second candidate cell to the first candidate entity, or send information about the first candidate cell to the first candidate entity without sending information about the second candidate cell. Furthermore, the source entity may send information about the first candidate cell and the second candidate cell to the second candidate entity, or send information about the second candidate cell to the second candidate entity without sending information about the first candidate cell.

[0208] In one possible implementation, step S1303 can be understood as an implementation of the first entity obtaining information about multiple candidate cells of the terminal device in step S1201 above. That is, when the first entity is the first candidate entity, the first entity obtaining information about multiple candidate cells of the terminal device in step S1201 above may include: the first candidate entity receiving information about one or more candidate cells from the source entity. The one or more candidate cells are candidate cells in candidate cell set 3.

[0209] In a possible implementation, the information of the candidate cells includes identification information of the candidate cells. The identification information of the candidate cells can refer to the relevant description in the above step S1201 and will not be repeated here.

[0210] In one possible implementation, in addition to the candidate cell information, the source entity may also send, to the candidate entity, one or more of the following: identification information assigned by the source entity to the terminal device, the source entity's own identification information, and identification information assigned by the candidate entity to the terminal device. The one or more pieces of information may be used to indicate that the candidate cell is a candidate cell for the terminal device.

[0211] For example, in a continuous CHO scenario, the source entity is a source base station and the candidate entity is a candidate base station, or, in a continuous CPAC scenario, the source entity is an MN and the candidate entity is a candidate SN, or, in a continuous inter-CU LTM scenario, the source entity is a source CU and the candidate entity is a candidate CU, the identification information allocated by the source entity and the candidate entity to the terminal device can be an XnAP ID. In the continuous CPCA scenario, the MN or SN can decide to configure one or more candidate PSCells for the terminal device, and the MN requests the candidate SN to allocate a candidate PSCell to the terminal device. In this case, the source entity can be an MN, and correspondingly, the candidate entity is a candidate SN.

[0212] Alternatively, for example, in a continuous intra-CU LTM scenario, when the source entity is a CU and the candidate entity is a DU, the candidate DUs are all managed by the same CU (ie, the source entity), and the identification information assigned by the source entity and the candidate entity to the terminal device can be an F1AP ID.

[0213] Optionally, when the source entity is a CU and the candidate entity is a candidate CU, after receiving information about multiple candidate cells, the candidate CU may send information about the multiple candidate cells to a first DU managed by the candidate CU to request the first DU to allocate a candidate cell to the terminal device. The cells managed by the first DU include at least one candidate cell from the multiple candidate cells.

[0214] Optionally, when the source entity is a CU and the candidate entity is a candidate CU, the candidate cell belongs to the candidate entity, which can be understood as: the candidate cell belongs to the DU managed by the candidate CU.

[0215] S1304: The terminal device switches to (or accesses) a first candidate cell. The first candidate entity determines that the terminal device switches to the first candidate cell.

[0216] In a possible implementation, such as in a continuous CHO or continuous CPAC scenario, after receiving the configuration information of multiple candidate cells, the terminal device can determine whether the trigger conditions corresponding to the candidate cells are met. If the trigger conditions of a candidate cell are met, the configuration information of the candidate cell is applied to access the candidate cell. Exemplarily, the terminal device can access the candidate cell through random access or other access methods that do not require random access, which is not limited. In the embodiment of the present application, the trigger conditions corresponding to the first candidate cell are met, and the terminal device successfully accesses the first candidate cell as an example for explanation.

[0217] In another possible implementation, such as in a continuous LTM scenario, after receiving configuration information for multiple candidate cells, the terminal device may measure the multiple candidate cells and report the Layer 1 measurement results of the candidate cells. The source service entity then instructs the terminal device to switch (cell switch) to the first candidate cell. For example, the source service entity may indicate the configuration identification information of the first candidate cell or the identification information of the first candidate cell. After receiving the instruction, the terminal device selects the first candidate cell as the target cell and accesses the target cell.

[0218] Exemplarily, the terminal device can access the target cell by random access, and when the random access is completed, it is considered that the terminal device has successfully switched or successfully accessed the first candidate cell; alternatively, the terminal device can access the target cell without random access. For example, when the source service entity instructs the terminal device to switch to the first candidate cell, it can indicate to the terminal device the configuration identification information, TA, uplink / downlink beam information for data transmission, etc. of the first candidate cell. The terminal device can perform uplink transmission / downlink reception based on the acquired TA and beam information of the target cell. At this time, if the terminal device performs the first uplink transmission or downlink reception on the beam indicated by the source service entity, it is considered that the terminal device has successfully switched or successfully accessed the first candidate cell.

[0219] It is understandable that after step S1304, the serving cell of the terminal device is the first candidate cell, and the serving entity is the first candidate entity. After the terminal device successfully switches / accesses to the first candidate cell, the first candidate entity can determine that the terminal device switches / accesses to the first candidate cell of the first candidate entity.

[0220] Optionally, when the source entity is a CU and the first candidate entity is a candidate CU, the first candidate entity determining that the terminal device switches to the first candidate cell may include: the candidate CU receives an access success indication from a second DU, where the access success indication is used to instruct the terminal device to switch to the first candidate cell. The second DU is a DU to which the first candidate cell managed by the candidate CU belongs.

[0221] Optionally, in a continuous CPCA scenario, if the above step S1303 adopts the third possible implementation method, then it can be considered that step S1304 is performed before step S1303.

[0222] Optionally, after the terminal device accesses the first candidate cell, it can perform measurements according to the measurement configuration and send a measurement report to the first candidate entity. Exemplarily, the measurement configuration can be sent by the first candidate entity to the terminal device, or it can be a measurement configuration sent by a source entity to the terminal device that is saved by the terminal device, that is, the terminal device continues to use the measurement configuration after accessing the first candidate cell. This application does not specifically limit this.

[0223] S1305. The serving entity sends first information based on information of one or more candidate cells.

[0224] The first information indicates the release of the second candidate cell. Exemplarily, the first information may indicate information about the released second candidate cell. The serving entity may determine the second candidate cell from one or more candidate cells, where the one or more candidate cells are candidate cells in candidate cell set 3, and the second candidate cell is one or more of the multiple candidate cells. For details, refer to the relevant description in step S1203 above, which will not be repeated here.

[0225] In a possible implementation, when the information of one or more candidate cells includes the respective identification information of one or more candidate cells (i.e., includes the identification information of the second candidate cell), the service entity sends the first information based on the information of the one or more candidate cells, which may include: the service entity determines to release the second candidate cell based on the respective identification information of the one or more candidate cells, and sends the first information after determining to release the second candidate cell.

[0226] Exemplarily, the service entity can identify one or more candidate cells based on the respective identification information of the one or more candidate cells. Afterwards, the first candidate entity can determine the cell to be released based on the measurement report and / or radio resource management (RRM) report information of the terminal device, and the cell to be released includes the second candidate cell. Exemplarily, the cell to be released can also be understood as a cell that is not suitable to continue to be a candidate cell for the terminal device. A cell is not suitable as a candidate cell for a terminal device can be understood as: the load in the cell is too high, such as the number of terminal devices accessing the cell exceeds a certain threshold, or the signal quality of the cell is poor, etc.

[0227] Exemplarily, the measurement report of the terminal device may indicate the signal quality of each candidate cell. In this scenario, the cell to be released may be a cell with a signal quality less than or equal to a certain threshold among one or more candidate cells.

[0228] In another possible implementation, if the service entity sends the configuration information of the first candidate cell to the source entity in step S1301, and the configuration information of the first candidate cell includes information of the cell to be released corresponding to the first candidate cell, the service entity determines the cell to be released in the configuration information as the second candidate cell.

[0229] In a possible implementation, the first information may include identification information of the second candidate cell. The identification information of the cell can refer to the relevant instructions in the above step S1201 and will not be repeated here. In addition, the service entity may also send at least one of the following: identification information assigned by the source entity to the terminal device, identification information assigned by the second candidate entity to the terminal device, or identification information of the source entity. The at least one item of information may be sent in the same message as the first information, or the at least one item of information may be understood as information in the first information, that is, the first information also includes at least one of the identification information assigned by the terminal device, identification information assigned by the second candidate entity to the terminal device, or identification information of the source entity.

[0230] In a possible implementation, the service entity may send the first information to the source entity, and accordingly, the source entity receives the first information from the service entity, and the source entity sends an indication of releasing the second candidate cell to the second candidate entity based on the first information, for example, executing the following step S1306. Alternatively, the service entity may send the first information to the second candidate entity, for example, when the service entity determines that there is an interface (such as an Xn interface, an X2 interface, or an F1 interface) between the service entity and the second candidate entity, the service entity sends the first information to the second candidate entity. The second candidate entity is the entity to which the second candidate cell belongs. Accordingly, the second candidate entity receives the first information from the source entity and determines the second candidate cell to be released by the terminal device based on the first information. That is, the service entity may indicate the release of the second candidate cell to the entity to which the second candidate cell belongs through the source entity, or may directly indicate the release of the second candidate cell to the entity to which the second candidate cell belongs.

[0231] S1306: The source entity sends the first information to the second candidate entity. Correspondingly, the second candidate entity receives the first information from the source entity.

[0232] The first information sent by the source entity to the second candidate entity indicates the release of the second candidate cell, or in other words, indicates the release of resources of the second candidate cell allocated to the terminal device.

[0233] Optionally, the first information sent by the source entity to the second candidate entity may contain the same or different content as the first information received by the source entity from the first candidate entity in step S1305. That is, after receiving the first information from the first candidate entity, the source entity may convert the information to obtain the first information sent to the second candidate entity. In other words, in this embodiment of the present application, any information that indicates the release of a candidate cell may be understood as the first information.

[0234] Optionally, when the second candidate cell includes one or more cells, when the service entity or source entity sends the first information to the second candidate entity, it can send the first information with the cell as the granularity, that is, one candidate cell corresponds to one first information, or send the first information with the candidate entity as the granularity, that is, one candidate entity corresponds to one first information.

[0235] For example, taking the case where the second candidate cell includes candidate cell 2, candidate cell 3 and candidate cell 4, and candidate cell 2 belongs to candidate entity 2, and candidate cell 3 and candidate cell 4 belong to candidate entity 3, the service entity or source entity can send three first messages, respectively indicating the release of candidate cell 2, candidate cell 3 and candidate cell 4; or, the service entity or source entity can send two first messages, one of which indicates the release of candidate cell 2, and the other first message indicates the release of candidate cell 3 and candidate cell 4.

[0236] Optionally, after receiving the first information from the serving entity or the source entity, the second candidate entity may identify the terminal device and the second candidate cell corresponding to the terminal device based on the first information, thereby releasing the resources of the second candidate cell allocated to the terminal device. The resources may be subsequently allocated to other terminal devices.

[0237] In a possible implementation manner, if the second candidate cell is a serving cell under the serving entity, the above steps S1305 and S1306 may not be performed.

[0238] In a possible implementation, after the above step S1304, the communication method may further include the following step S1307:

[0239] S1307: The service entity sends second information to the terminal device. Correspondingly, the terminal device receives the second information from the service entity, wherein the second information indicates the release of the second candidate cell or indicates configuration information for releasing the second candidate cell.

[0240] Exemplarily, the second information may include identification information of the second candidate cell. The terminal device may learn the candidate cell to be released based on the second information, thereby releasing the second candidate cell.

[0241] In one possible implementation, the terminal device releases the second candidate cell, which can be understood as: the terminal device releases (or deletes or discards) the configuration information of the second candidate cell. Exemplarily, the configuration information of the second candidate cell may be sent by the source entity to the terminal device in step S1302 above. In step S1302, if the source entity configures the corresponding execution trigger condition for the second candidate cell, the terminal device may also release (or delete or discard) the execution trigger condition corresponding to the second candidate cell.

[0242] In another possible implementation, the terminal device releasing the second candidate cell can be understood as the terminal device deactivating (or disabling) the second candidate cell. For example, the terminal device retains the configuration information of the second candidate cell, but does not continue to evaluate whether the second candidate cell can be used as a target cell in a subsequent handover process, or does not perform measurements on the second candidate cell.

[0243] In one possible implementation, in a continuous CPAC scenario, after step S1304, the source entity sends a second message to the terminal device. Accordingly, the terminal device receives the second message from the source entity, learns the second candidate cell to be released, and releases the second candidate cell. For details, see step S1307, which is not detailed here.

[0244] It should be noted that there is no strict order for step S1307 and step S1305. Step S1307 may be performed first, followed by step S1305; or step S1305 may be performed first, followed by step S1307; or step S1305 and step S1307 may be performed simultaneously. This application does not impose any specific restrictions on this.

[0245] In another possible implementation, if the configuration information of the first candidate cell in step S1302 includes information about the cell to be released (i.e., the second candidate cell) corresponding to the first candidate cell, after step S1304, the terminal device can obtain the cell to be released when applying the configuration information of the target cell, thereby releasing the second candidate cell. In addition, in this implementation, step S1307 may not be performed.

[0246] Based on this solution, the service entity sends a second information to the terminal device to instruct the terminal device to release the second candidate cell, or the terminal device obtains information about the released candidate cell (i.e., the second candidate cell) when applying the configuration information of the target cell. This allows the terminal device to release or deactivate the configuration information of the second candidate cell, thereby not continuing to evaluate whether the second candidate cell can be used as the target cell in subsequent switching processes, which can reduce the judgment complexity and power consumption of the terminal device.

[0247] In some implementation scenarios, when the first entity is a source entity, as shown in FIG14 , the communication method provided by this application includes the following steps:

[0248] S1401. The source entity obtains configuration information of multiple candidate cells of the terminal device.

[0249] In the case where the first entity is the source entity, the first entity obtaining information of multiple candidate cells of the terminal device in the above step S1201 can be understood as: the source entity obtains configuration information of multiple candidate cells of the terminal device. For specific implementation, please refer to the relevant instructions in the above step S1301.

[0250] In a possible implementation, when the source entity obtains configuration information of multiple candidate cells of the terminal device, it can simultaneously determine identification information of the multiple candidate cells of the terminal device.

[0251] S1402: The source entity sends configuration information of multiple candidate cells to the terminal device. Please refer to the relevant description in the above step S1302, which will not be repeated here.

[0252] S1403: The terminal device switches to (or accesses) the first candidate cell. The first candidate entity determines that the terminal device switches to the first candidate cell. Please refer to the relevant description in the above step S1304, which will not be repeated here.

[0253] S1404: The first candidate entity sends third information to the source entity. Correspondingly, the source entity receives the third information from the first candidate entity.

[0254] In one possible implementation, the third information indicates that the terminal device (successfully) switches to / accesses the first candidate entity, or further, the third information indicates that the terminal device switches to / accesses the first candidate cell. Exemplarily, the third information may include identification information of the first candidate cell.

[0255] In this scenario, after receiving the third information, the source entity can learn that the serving entity of the terminal device is the first candidate entity. In addition, the source entity can also learn that the serving cell of the terminal device is the first candidate cell, that is, the source entity can determine that the terminal device is switched / accessed to the first candidate cell of the first candidate entity.

[0256] That is to say, when the first entity is the source entity, the first entity described in the above step S1201 determines that the terminal device switches to the first candidate cell of the first candidate entity, including: the source entity receives third information from the first candidate entity, and determines that the terminal device switches to the first candidate cell of the first candidate entity based on the third information.

[0257] S1405. The source entity sends first information based on information of one or more candidate cells.

[0258] The first information indicates the release of the second candidate cell, where the second candidate cell is one or more of the one or more candidate cells. The one or more candidate cells may be candidate cells in candidate cell set 2. Exemplarily, the first information may indicate information about the released second candidate cell. Please refer to the relevant description in step S1203 above and will not be repeated here.

[0259] In a possible implementation, after determining that the terminal device switches to a candidate cell, the source entity sends first information to instruct the release of some or all candidate cells.

[0260] Regarding the determination of the second candidate cell:

[0261] In one possible implementation, the source entity may determine a second candidate cell from the one or more candidate cells. For example, when the information of the one or more candidate cells includes identification information of each of the one or more candidate cells, the source entity sending the first information based on the information of the one or more candidate cells may include: the source entity determining to release the second candidate cell based on the identification information of each of the one or more candidate cells, and sending the first information after determining to release the second candidate cell.

[0262] Exemplarily, the source entity may identify one or more candidate cells based on their respective identification information. Subsequently, the source entity may determine a second candidate cell based on neighboring cell information of the serving cell (i.e., the first candidate cell). For example, the second candidate cell may not be a neighboring cell of the first candidate cell.

[0263] Alternatively, illustratively, the source entity may identify one or more candidate cells based on respective identification information of the one or more candidate cells, and then determine a second candidate cell based on a preset number of handovers and / or a timer.

[0264] As a first possible implementation, each of the multiple candidate cells of the terminal device corresponds to a preset number of handovers. When the number of times the terminal device switches to a candidate cell is greater than or equal to the preset number of handovers corresponding to the candidate cell, the source entity determines to release the candidate cell (i.e., the second candidate cell).

[0265] Exemplarily, taking candidate cell 2 as an example, each time a terminal device switches to candidate cell 2, the candidate entity to which candidate cell 2 belongs may indicate to the source entity that the terminal device has switched to candidate cell 2, so that the source entity can count the number of times the terminal device has switched to candidate cell 2. Alternatively, the source entity and the candidate entity may agree on a preset number of switching times corresponding to candidate cell 2, and the candidate entity can count the number of times the terminal device has switched to candidate cell 2. When the number of times the terminal device has switched to candidate cell 2 is greater than or equal to its corresponding preset number of switching times, the candidate entity indicates to the source entity that the number of times the terminal device has switched to candidate cell 2 is greater than or equal to its corresponding preset number of switching times.

[0266] As a second possible implementation, multiple candidate cells of the terminal device may correspond to a preset number of handovers. When the number of handovers of the terminal device (regardless of the candidate cells, or the sum of the number of times the terminal device switches to each candidate cell) is greater than or equal to the preset number of handovers, the source entity determines to release all or part of the candidate cells of the terminal device (i.e., the second candidate cell).

[0267] As a third possible implementation, each of the multiple candidate cells of the terminal device corresponds to a timer. When the timer corresponding to a candidate cell times out or the running time reaches a preset value, the source entity determines to release the candidate cell (ie, the second candidate cell).

[0268] As a fourth possible implementation, multiple candidate cells of the terminal device may correspond to one timer. When the timer times out or the allowed time reaches a preset value, the source entity determines to release all or part of the candidate cells (ie, the second candidate cells) of the terminal device.

[0269] Exemplarily, the timer may be started when the source entity receives configuration information of a candidate cell sent by a candidate entity; or, the timer may be started when the source entity sends an RRC reconfiguration message carrying configuration information of multiple candidate cells to the terminal device; or, the timer may be started when the source entity receives an RRC reconfiguration complete message from the terminal device; or, the timer may be started after the terminal device completes a first handover. The first handover may be the first handover after the source entity sends configuration information of multiple candidate cells to the terminal device.

[0270] Optionally, the above-mentioned preset number of switching times, timer duration, or preset value can be defined by the protocol, or can be determined by the source entity itself, or can be negotiated between the source entity and the candidate entity. This application does not make specific limitations on this.

[0271] In another possible implementation, the source entity may obtain the second candidate cell information from another entity. For example, in a continuous CPAC scenario, the source SN may determine the second candidate cell and then send the second candidate cell information to the source entity.

[0272] In a possible implementation, the first information may include identification information of the second candidate cell. For the identification information of the candidate cell, reference may be made to the relevant description in the above step S1201 and will not be repeated here.

[0273] In one possible implementation, in step S1405, the source entity may send the first information to the second candidate entity. Furthermore, the source entity may send at least one of the following to the second candidate entity: identification information assigned by the source entity to the terminal device, identification information assigned by the second candidate entity to the terminal device, or identification information of the source entity itself. For details, please refer to the relevant description in step S1306 above and will not be repeated here.

[0274] In a possible implementation, in step S1405, the source entity may further send the first information to the service entity (ie, the first candidate entity). In this case, the method may further include the following step S1406:

[0275] S1406: The service entity sends a second message to the terminal device. Accordingly, the terminal device receives the second message from the service entity. The second message indicates that the second candidate cell should be released. For details, refer to the description of step S1307 above and will not be repeated here.

[0276] In another possible implementation, in step S1405, the source entity may not send the first information to the serving entity, and step S1406 may not be performed. In this case, the source entity may send the second information to the terminal device. For example, in a continuous CPAC scenario, when the MN acts as the source entity, after configuring one or more candidate cell configuration information for the terminal device in step S1402, the MN may send the second information to the terminal device to instruct the terminal device to release the second candidate cell.

[0277] In another possible implementation, the source entity may send second information to the terminal device in step S1402, i.e., the configuration information of the first candidate cell may include the second information, or information about the second candidate cell. After step S1403, when the terminal device applies the configuration information of the target cell, it may obtain the released candidate cell, or obtain information about the second candidate cell, thereby releasing the second candidate cell. For details, please refer to the relevant description of the method shown in Figure 13 above, which will not be repeated here.

[0278] Based on this solution, the source entity can, after determining that the terminal device has accessed the first candidate cell, send a first message to instruct the release of one or more other candidate cells. When the source entity sends the first message to the candidate entity to which the candidate cell to be released belongs, the candidate entity can promptly release the cell radio resources reserved for the terminal device, avoiding the situation where the terminal device excessively occupies the cell radio resources and cannot allocate the resources to other terminal devices, thereby achieving efficient utilization of cell resources.

[0279] In addition, the source entity sends a first message to the service entity, so that the service entity can send a second message to the terminal device to instruct the terminal device to release the second candidate cell, thereby causing the terminal device to release or deactivate the configuration information of the second candidate cell, and then no longer continue to evaluate whether the second candidate cell can be used as the target cell in the subsequent switching process, which can reduce the judgment complexity and power consumption of the terminal device.

[0280] In some implementation scenarios, when the first entity is a candidate entity and the candidate entity is not a serving entity, as shown in FIG15 , the communication method provided in this application includes the following steps:

[0281] S1501. The source entity obtains configuration information of multiple candidate cells of the terminal device.

[0282] S1502. The source entity sends configuration information of multiple candidate cells to the terminal device.

[0283] S1503: The source entity sends information about at least one candidate cell of the terminal device to at least one candidate entity. Correspondingly, the candidate entity receives the information about at least one candidate cell of the terminal device from the source entity.

[0284] S1504: The terminal device switches to (or accesses) a first candidate cell. The first candidate entity determines that the terminal device switches to the first candidate cell.

[0285] Among them, the implementation of steps S1501-S1504 can refer to the relevant instructions in the above steps S1301-S1304, which will not be repeated here.

[0286] S1505: The serving entity (ie, the first candidate entity) sends third information to the second candidate entity. Correspondingly, the second candidate entity receives the third information from the first candidate entity.

[0287] Among them, the implementation of the third information can refer to the relevant instructions of the third information in the above step S1404, and the implementation after the second candidate entity receives the third information can refer to the implementation after the source entity receives the third information in the above step S1404, which will not be repeated here.

[0288] S1506. The second candidate entity sends first information according to information of one or more candidate cells.

[0289] The first information indicates releasing the second candidate cell, and the second candidate cell is one or more of the one or more candidate cells. The one or more candidate cells may be candidate cells in the candidate cell set 3. The second candidate entity may determine the second candidate cell from the one or more candidate cells.

[0290] In a possible implementation, after determining that the terminal device switches to a certain candidate cell, the second candidate entity sends first information to instruct to release some or all of the other candidate cells.

[0291] In a possible implementation, when the information of one or more candidate cells includes the respective identification information of one or more candidate cells, the second candidate entity sends the first information based on the information of the one or more candidate cells, which may include: the second candidate entity determines to release the second candidate cell based on the respective identification information of the one or more candidate cells, and sends the first information after determining to release the second candidate cell.

[0292] As a possible implementation, the second candidate entity may identify one or more candidate cells based on their respective identification information. Subsequently, the second candidate entity may determine the cell to be released based on a preset number of handovers and / or a timer. Reference may be made to the aforementioned implementation of the source entity determining the cell to be released in step S1405, which will not be further described here.

[0293] As another possible implementation, the second candidate entity may identify at least one candidate cell of the second candidate entity from the one or more candidate cells based on the identification information of each of the one or more candidate cells. Then, the second candidate cell may be released based on the load of the at least one candidate cell. For example, if the load of the second candidate cell is greater than or equal to a load threshold, the second candidate cell may be released.

[0294] As another possible implementation, the source entity may identify one or more candidate cells based on their respective identification information. The source entity then determines a second candidate cell based on neighboring cell information of the serving cell (i.e., the first candidate cell). For example, the second candidate cell may not be a neighboring cell of the first candidate cell.

[0295] In a possible implementation, the second candidate entity may send the first information to the serving entity. In this case, the method may further include the following step S1507:

[0296] S1507: The service entity sends a second message to the terminal device. Accordingly, the terminal device receives the second message from the service entity. The second message indicates that the second candidate cell should be released. For details, refer to the above description of step S1307 and will not be repeated here.

[0297] Optionally, when the second candidate cell determined by the second candidate entity includes a cell in the third candidate entity (denoted as candidate cell 3), the second candidate entity may further send first information to the third candidate entity to instruct the release of candidate cell 3. Alternatively, the second candidate entity may further send information to the source entity to instruct the release of candidate cell 3, and the source entity then instructs the third candidate entity to release candidate cell 3.

[0298] In a possible implementation, in a continuous CPAC scenario, the second candidate entity may send the first information to the source entity. In this case, the method may further include the following step S1507' (not shown in FIG15 ):

[0299] S1507': ​​The source entity sends the second information to the terminal device. Correspondingly, the terminal device receives the second information from the source entity. Please refer to the relevant description in the above step S1307, which will not be repeated here.

[0300] Based on this solution, the second candidate entity can send the first candidate entity after determining that the terminal device accesses the first candidate cell, so that the first candidate entity can send the second information to the terminal device to instruct the terminal device to release the second candidate cell, thereby causing the terminal device to release or deactivate the configuration information of the second candidate cell, and then no longer continue to evaluate whether the second candidate cell can be used as the target cell in the subsequent switching process, which can reduce the judgment complexity and power consumption of the terminal device.

[0301] In addition, the second candidate entity sends information to indicate the release of other cells to be released, so that the candidate entity to which the cell to be released belongs can promptly release the cell wireless resources reserved for the terminal device, avoiding the situation where the terminal device excessively occupies the cell wireless resources and cannot allocate the resources to other terminal devices, thereby achieving efficient utilization of cell resources.

[0302] In the above solution, the network side instructs the release of the candidate cell. In addition, the present application also provides a communication method, which can be instructed by the terminal device to release the candidate cell. As shown in Figure 16, the communication method includes the following steps:

[0303] S1601. The source entity obtains information of multiple candidate cells of the terminal device.

[0304] In one possible implementation, the information of the multiple candidate cells is configuration information of the multiple candidate cells. When the source entity obtains the configuration information of the multiple candidate cells, it can also obtain the identification information of each of the multiple candidate cells. The implementation of step S1601 can refer to the relevant description of step S1301 above and will not be repeated here.

[0305] S1602: The source entity sends information of multiple candidate cells to the terminal device. Please refer to the relevant description in the above step S1302, which will not be repeated here.

[0306] S1603: The terminal device switches to (or accesses) the first candidate cell. Please refer to the relevant description in the above step S1304, which will not be repeated here.

[0307] S1604: The terminal device sends first information to the service entity. Correspondingly, the service entity receives the first information from the terminal device.

[0308] In a possible implementation, in a continuous CPAC scenario, step S1604 may be replaced by: the terminal device sends the first information to the source entity. Correspondingly, the source entity receives the first information from the terminal device.

[0309] The first information indicates the release of the second candidate cell, and the second candidate cell is one or more of the multiple candidate cells. Please refer to the relevant description in the above step S1203, which will not be repeated here.

[0310] In one possible implementation, when the information about multiple candidate cells includes configuration information or identification information of each of the multiple candidate cells, the terminal device identifies the multiple candidate cells based on the configuration information or identification information of the multiple candidate cells. The terminal device then determines, based on the cell release conditions, a cell that is not suitable to continue to be a candidate cell for the terminal device, i.e., determines a cell to be released, and sends information to the first candidate entity to indicate the cell to be released.

[0311] Exemplarily, the cell release condition may be configured by the source entity to the terminal device, or may be predefined by the protocol, or may be determined by the terminal device itself, and this application does not impose any specific limitation on this.

[0312] Optionally, when the source entity configures cell release conditions for the terminal device, the communication method further includes: the source entity sending second information to the terminal device. Accordingly, the terminal device receives the second information from the source entity. The second information is used to indicate conditions for releasing the second candidate cell. The second information may also be used to indicate conditions for releasing other candidate cells.

[0313] Exemplarily, the second information and the configuration information of multiple candidate cells may be carried in the same message, or the second information and the configuration information of multiple candidate cells may be carried in different messages, which is not specifically limited in this application.

[0314] In a possible implementation, the second information may include information indicating a timer and / or a maximum number of handovers corresponding to the second candidate cell.

[0315] As a first possible implementation, the second information may include information indicating a timer and / or a maximum number of handovers corresponding to each of the multiple candidate cells, that is, each of the multiple candidate cells of the terminal device corresponds to a timer and / or a maximum number of handovers.

[0316] When the number of times the terminal device switches to a candidate cell is greater than or equal to the maximum number of switches corresponding to the candidate cell, and / or the timer corresponding to the candidate cell times out or the running time reaches a preset value, the terminal device determines to release the candidate cell, that is, the second candidate cell includes the candidate cell.

[0317] Exemplarily, the terminal device may maintain a counter for each of the multiple candidate cells, for example, counter 1 for candidate cell 1 and counter 2 for candidate cell 2. Each time the terminal device switches to a candidate cell, the counter corresponding to the candidate cell is incremented by 1. When the value of the counter reaches the maximum number of switching times corresponding to the candidate cell, the candidate cell is determined to be released.

[0318] Alternatively, the terminal device may maintain a timer for each of the multiple candidate cells, for example, maintaining timer 1 for candidate cell 1 and timer 2 for candidate cell 2. When the timer corresponding to a candidate cell times out or the running time reaches a preset value, the terminal device determines to release the candidate cell.

[0319] As a second possible implementation, the second information may include information indicating a timer and / or a maximum number of handovers corresponding to the multiple candidate cells, that is, the multiple candidate cells of the terminal device all correspond to the same timer and / or maximum number of handovers.

[0320] When the number of switching times of the terminal device is greater than or equal to the maximum number of switching times, and / or the timer times out or the running time reaches a preset value, the terminal device determines to release all or part of the candidate cells of the terminal device, that is, the second candidate cell includes all or part of the candidate cells of the terminal device.

[0321] For example, the terminal device may maintain a counter for multiple candidate cells. Each time the terminal device switches to a candidate cell, the counter increments by 1. When the counter reaches the maximum number of handovers, all or some of the terminal device's candidate cells are released. Alternatively, the terminal device may maintain a timer for multiple candidate cells. When the timer expires or reaches a preset time, all candidate cells for the terminal device are released.

[0322] In a possible implementation, the first information may include identification information of the second candidate cell. For the identification information of the candidate cell, reference may be made to the relevant description in the above step S1201 and will not be repeated here.

[0323] In a possible implementation, after the terminal device determines the second candidate cell, the second candidate cell may be released. For details, please refer to the relevant description in step S1307 above, which will not be repeated here.

[0324] In a possible implementation, when the terminal device sends the first information to the service entity, the method may further include the following step S1605:

[0325] S1605. The service entity sends the first information.

[0326] Optionally, the service entity may send the first information to the source entity, and accordingly, the source entity receives the first information from the service entity. Alternatively, the service entity may send the first information to the second candidate entity, and accordingly, the second candidate entity receives the first information from the service entity, wherein the second candidate entity is the entity to which the second candidate cell belongs. In addition, the service entity may also send at least one of the following: identification information assigned by the source entity to the terminal device, identification information assigned by the second candidate entity to the terminal device, or identification information of the source entity. Please refer to the relevant instructions in the above step S1305, which will not be repeated here.

[0327] In another possible implementation, when the terminal device sends the first information to the source entity, or when the service entity sends the first information to the source entity after receiving the first information from the terminal device, the method may further include the following step S1606:

[0328] S1606: The source entity sends the first information to the second candidate entity. Correspondingly, the second candidate entity receives the first information from the source entity.

[0329] The first information sent by the source entity to the second candidate entity indicates the release of the second candidate cell, or in other words, indicates the release of resources allocated to the terminal device for the second candidate cell. Furthermore, the source entity may also send at least one of the following: identification information allocated by the source entity to the terminal device, identification information allocated by the second candidate entity to the terminal device, or identification information of the source entity. Please refer to the relevant description in step S1306 above and will not be repeated here.

[0330] Optionally, after receiving the first information, the second candidate entity may release resources of the second candidate cell reserved for the terminal device based on the instruction of the first information, and subsequently allocate the resources to other terminal devices.

[0331] Based on this solution, the terminal device can send the first information to the first candidate entity, so that the first candidate entity can send information to the second candidate entity to instruct it to release the second candidate cell. This can enable the second candidate entity to promptly release the cell radio resources reserved for the terminal device, avoiding the situation where the terminal device excessively occupies the cell radio resources and cannot allocate the resources to other terminal devices, thereby achieving efficient utilization of cell resources. In addition, the terminal device can release or deactivate the configuration information of the second candidate cell, so as not to continue to evaluate whether the second candidate cell can be used as the target cell in the subsequent handover process, which can reduce the terminal device's judgment complexity and power consumption.

[0332] It is understood that in each of the above embodiments, the methods and / or steps implemented by the RAN entity may also be implemented by components applicable to the RAN entity (e.g., processor, chip, chip system, circuit, logic module, or software); and the methods and / or steps implemented by the terminal device may also be implemented by components applicable to the terminal device (e.g., processor, chip, chip system, circuit, logic module, or software). The chip system may be composed of a chip, or may include a chip and other discrete components.

[0333] It is understandable that, in order to realize the above functions, the communication device includes hardware structures and / or software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0334] The embodiment of the present application can divide the functional modules of the communication device according to the above method embodiment. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0335] Communication Device Figure 17 shows a schematic structural diagram of a communication device 170. The communication device 170 includes a processing module 1701 and a transceiver module 1702. The communication device 170 can be used to implement the functions of the above-mentioned RAN entity or terminal device.

[0336] In some embodiments, the communication device 170 may further include a storage module (not shown in FIG. 17 ) for storing program instructions and data.

[0337] In some embodiments, the transceiver module 1702, which may also be referred to as a transceiver unit, is configured to implement a transmitting and / or receiving function. The transceiver module 1702 may be composed of a transceiver circuit, a transceiver, a transceiver, or a communication interface.

[0338] In some embodiments, the transceiver module 1702 may include a receiving module and a sending module, which are respectively used to execute the receiving and sending steps performed by the RAN entity or terminal device in the above method embodiments, and / or used to support other processes of the technology described in this document; the processing module 1701 may be used to execute the processing steps (such as determination, etc.) performed by the RAN entity or terminal device in the above method embodiments, and / or used to support other processes of the technology described in this document.

[0339] When the communication device 170 is used to implement the functions of the first entity:

[0340] Processing module 1701 is used to obtain information of multiple candidate cells of the terminal device; processing module 1701 is also used to determine the first candidate cell to which the terminal device switches to the first candidate entity, where the first candidate cell is one of multiple candidate cells; transceiver module 1702 is used to send first information based on the information of the multiple candidate cells, where the first information indicates the release of the second candidate cell, where the second candidate cell is one or more of the multiple candidate cells.

[0341] Optionally, the processing module 1701 is used to obtain information about multiple candidate cells of the terminal device, including: the processing module 1701 is used to receive information about multiple candidate cells from a source entity through the transceiver module 1702.

[0342] Optionally, the transceiver module 1702 is used to send the first information, including: the transceiver module 1702 is used to send the first information to the source entity or the second candidate entity, and the second candidate entity is the entity to which the second candidate cell belongs.

[0343] Optionally, the transceiver module 1702 is further configured to send second information to the terminal device, where the second information indicates releasing configuration information of the second candidate cell.

[0344] Optionally, the transceiver module 1702 is used to send the second information to the terminal device, including: the transceiver module 1702 is used to send the configuration information of the first candidate cell to the terminal device, the configuration information of the first candidate cell includes the second information, and the configuration information of the first candidate cell is used for the terminal device to access the first candidate cell.

[0345] Optionally, the processing module 1701 is used to determine that the terminal device switches to the first candidate cell of the first candidate entity, including: the processing module 1701 is used to receive third information from the first candidate entity through the transceiver module 1702, and the third information indicates that the terminal device switches to the first candidate cell.

[0346] Optionally, the transceiver module 1702 is configured to send the first information, including: the transceiver module 1702 is configured to send the first information to the first candidate entity.

[0347] When the communication device 170 is used to implement the functions of the terminal device:

[0348] Transceiver module 1702 is configured to receive information about multiple candidate cells from a source entity. Processing module 1701 is configured to switch to a first candidate cell of a first candidate entity, where the first candidate cell is one of the multiple candidate cells. Transceiver module 1702 is further configured to send first information to the first candidate entity, where the first information indicates the release of a second candidate cell, where the second candidate cell is one or more of the multiple candidate cells.

[0349] Optionally, the transceiver module 1702 is further configured to receive second information from the source entity, where the second information is used to indicate a condition for releasing the second candidate cell.

[0350] Optionally, the second information includes information indicating a timer and / or a maximum number of switching times corresponding to the second candidate cell.

[0351] Optionally, the processing module 1701 is further configured to determine to release the second candidate cell when the timer times out.

[0352] Optionally, the processing module 1701 is further configured to determine to release the second candidate cell when the number of handovers to the second candidate cell is greater than or equal to the maximum number of handovers.

[0353] When the communication device 170 is used to implement the function of the source entity:

[0354] In one possible implementation, transceiver module 1702 is configured to send information about multiple candidate cells of a terminal device to a first candidate entity, where the first candidate entity is an entity to which the first candidate cell belongs, and the first candidate cell is one of the multiple candidate cells. Transceiver module 1702 is further configured to receive first information from the first candidate entity, where the first information indicates the release of a second candidate cell, and the second candidate cell is one or more of the multiple candidate cells. Transceiver module 1702 is further configured to send the first information to a second candidate entity, where the second candidate entity is an entity to which the second candidate cell belongs.

[0355] In another possible implementation, the transceiver module 1702 is configured to send information about multiple candidate cells to the terminal device. The transceiver module 1702 is further configured to send second information to the terminal device, where the second information is used to indicate a condition for releasing at least one of the multiple candidate cells.

[0356] Optionally, the transceiver module 1702 is further configured to receive first information from a first candidate entity, where the first information indicates releasing the second candidate cell, where the first candidate entity is an entity to which the first candidate cell belongs, the first candidate cell is a serving cell of a terminal device, and the second candidate cell is one or more of multiple candidate cells. The transceiver module 1702 is further configured to send information indicating the release of the second candidate cell to the second candidate entity, where the second candidate entity is an entity to which the second candidate cell belongs.

[0357] Optionally, the second information includes information indicating a timer and / or a maximum number of switching times corresponding to each of the multiple candidate cells.

[0358] When the communication device 170 is used to implement the function of the first candidate entity:

[0359] The transceiver module 1702 is used to receive information about multiple candidate cells of a terminal device from a source entity; the processing module 1701 is used to determine that the terminal device switches to the first candidate cell of the first candidate entity, where the first candidate cell is one of multiple candidate cells; the transceiver module 1702 is also used to send third information to the source entity or the second candidate entity, where the third information indicates that the terminal device switches to the first candidate cell, where the second candidate entity is the entity to which the second candidate cell belongs, and where the second candidate cell is one or more of the multiple candidate cells; the transceiver module 1702 is also used to receive first information from the source entity or the second candidate entity, where the first information indicates the release of the second candidate cell.

[0360] Optionally, the transceiver module 1702 is further configured to send second information to the terminal device according to the first information, where the second information indicates releasing configuration information of the second candidate cell.

[0361] Among them, all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, and will not be repeated here.

[0362] In the present application, the communication device 170 may be presented in the form of various functional modules divided in an integrated manner. The "module" here may refer to a specific application-specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions.

[0363] In some embodiments, when the communication device 170 in Figure 17 is a chip or a chip system, the function / implementation process of the transceiver module 1702 can be implemented through the input and output interface (or communication interface) of the chip or chip system, and the function / implementation process of the processing module 1701 can be implemented through the processor (or processing circuit) of the chip or chip system.

[0364] Since the communication device 170 provided in this embodiment can execute the above method, the technical effects that can be obtained can refer to the above method embodiments and will not be repeated here.

[0365] As a possible product form, the terminal device or RAN entity described in the embodiments of the present application can also be implemented using the following: one or more field programmable gate arrays (FPGAs), programmable logic devices (PLDs), controllers, state machines, gate logic, discrete hardware components, any other suitable circuits, or any combination of circuits that can perform the various functions described throughout this application.

[0366] As another possible product form, the terminal device or RAN entity described in the embodiment of the present application can be implemented by a general bus architecture. For ease of explanation, refer to Figure 18, which is a structural diagram of a communication device 1800 provided in an embodiment of the present application. The communication device 1800 includes a processor 1801 and a transceiver 1802. The communication device 1800 can be a RAN entity, or a chip or chip system therein; or, the communication device 1800 can be a terminal device, or a chip or module therein. Figure 18 only shows the main components of the communication device 1800. In addition to the processor 1801 and the transceiver 1802, the communication device can further include a memory 1803 and an input and output device (not shown in the figure).

[0367] Optionally, processor 1801 is primarily used to process communication protocols and communication data, as well as control the entire communication device, execute software programs, and process software program data. Memory 1803 is primarily used to store software programs and data. Transceiver 1802 may include a radio frequency circuit and an antenna. The radio frequency circuit is primarily used to convert baseband signals into radio frequency signals and process radio frequency signals. The antenna is primarily used to transmit and receive radio frequency signals in the form of electromagnetic waves. Input and output devices, such as a touch screen, display, and keyboard, are primarily used to receive user input and output data to the user.

[0368] Optionally, the processor 1801 , the transceiver 1802 , and the memory 1803 may be connected via a communication bus.

[0369] When the communication device is powered on, the processor 1801 can read the software program in the memory 1803, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor 1801 performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then transmits the radio frequency signal to the outside in the form of electromagnetic waves via the antenna. When data is sent to the communication device, the radio frequency circuit receives the radio frequency signal via the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 1801. The processor 1801 converts the baseband signal into data and processes the data.

[0370] In another implementation, the RF circuit and antenna may be provided independently of the processor performing baseband processing. For example, in a distributed scenario, the RF circuit and antenna may be remotely arranged independent of the communication device.

[0371] In some embodiments, in terms of hardware implementation, those skilled in the art may conceive that the above-mentioned communication device 170 may take the form of a communication device 1800 shown in FIG. 18 .

[0372] As an example, the functions / implementation process of the processing module 1701 in FIG17 can be implemented by the processor 1801 in the communication device 1800 shown in FIG18 calling the computer-executable instructions stored in the memory 1803. The functions / implementation process of the transceiver module 1702 in FIG17 can be implemented by the transceiver 1802 in the communication device 1800 shown in FIG18.

[0373] As another possible product form, the RAN entity or terminal device in this application may adopt the structure shown in Figure 19, or include the components shown in Figure 19. Figure 19 is a schematic diagram of the structure of a communication device 1900 provided in this application. The communication device 1900 may be a terminal device or a chip or system-on-chip in the terminal device; or it may be a RAN entity or a module, chip or system-on-chip in the RAN entity.

[0374] As shown in FIG19 , the communication device 1900 includes at least one processor 1901 and at least one communication interface ( FIG19 is merely an example of one communication interface 1904 and one processor 1901). Optionally, the communication device 1900 may further include a communication bus 1902 and a memory 1903.

[0375] Processor 1901 can be a general-purpose central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Processor 1901 can also be other devices with processing capabilities, such as circuits, devices, or software modules, without limitation.

[0376] Communication bus 1902 is used to connect the various components in communication device 1900, enabling communication between them. Communication bus 1902 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, for example. This bus can be categorized as an address bus, a data bus, a control bus, and so on. For ease of illustration, FIG19 shows a single bold line, but this does not imply that there is only one bus or type of bus.

[0377] Communication interface 1904 is used to communicate with other devices or communication networks. Exemplarily, communication interface 1904 can be a module, circuit, transceiver, or any other device capable of communication. Optionally, communication interface 1904 can also be an input / output interface within processor 1901, used to implement signal input and output to the processor.

[0378] The memory 1903 may be a device with a storage function, used to store instructions and / or data, wherein the instructions may be computer programs.

[0379] Exemplarily, the memory 1903 may be a read-only memory (ROM) or other types of static storage devices that can store static information and / or instructions, or a random access memory (RAM) or other types of dynamic storage devices that can store information and / or instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, etc., without limitation.

[0380] It should be noted that the memory 1903 can exist independently of the processor 1901 or can be integrated with the processor 1901. The memory 1903 can be located within the communication device 1900 or outside the communication device 1900, without limitation. The processor 1901 can be used to execute instructions stored in the memory 1903 to implement the methods provided in the following embodiments of the present application.

[0381] As an optional implementation, the communication device 1900 may further include an output device 1905 and an input device 1906. The output device 1905 communicates with the processor 1901 and can display information in a variety of ways. For example, the output device 1905 can be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device 1906 communicates with the processor 1901 and can receive user input in a variety of ways. For example, the input device 1906 can be a mouse, a keyboard, a touch screen device, or a sensor device.

[0382] In some embodiments, in terms of hardware implementation, those skilled in the art may conceive that the communication device 170 shown in FIG. 17 may take the form of the communication device 1900 shown in FIG. 19 .

[0383] As an example, the functions / implementation process of the processing module 1701 in FIG17 can be implemented by the processor 1901 in the communication device 1900 shown in FIG19 calling the computer-executable instructions stored in the memory 1903. The functions / implementation process of the transceiver module 1702 in FIG17 can be implemented by the communication interface 1904 in the communication device 1900 shown in FIG19.

[0384] It should be noted that the structure shown in Figure 19 does not constitute a specific limitation on the RAN entity or terminal device. For example, in other embodiments of the present application, the RAN entity or terminal device may include more or fewer components than shown, or some components may be combined or separated, or arranged differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0385] In some embodiments, an embodiment of the present application further provides a communication device, which includes a processor for implementing the method in any of the above method embodiments.

[0386] As a possible implementation, the communication device further includes a memory. The memory is used to store necessary computer programs and data. The computer program may include instructions, and the processor may invoke the instructions in the computer program stored in the memory to instruct the communication device to execute any of the above-described method embodiments. Of course, the memory may not be located in the communication device.

[0387] As another possible implementation, the communication device also includes an interface circuit, which is a code / data read / write interface circuit, and the interface circuit is used to receive computer execution instructions (computer execution instructions are stored in a memory, may be read directly from the memory, or may pass through other devices) and transmit them to the processor.

[0388] As another possible implementation, the communication device further includes a communication interface, where the communication interface is used to communicate with a module outside the communication device.

[0389] It can be understood that the communication device can be a chip or a chip system. When the communication device is a chip system, it can be composed of chips or include chips and other discrete devices. The embodiments of the present application do not specifically limit this.

[0390] The present application also provides a computer-readable storage medium having a computer program or instruction stored thereon, which implements the functions of any of the above method embodiments when executed by a computer.

[0391] The present application also provides a computer program product, which implements the functions of any of the above method embodiments when executed by a computer.

[0392] Those skilled in the art will appreciate that, for the sake of convenience and brevity of description, the specific working processes of the above-described systems, devices, and units may refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0393] It is understood that the systems, devices, and methods described in this application may also be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection shown or discussed may be through some interface, indirect coupling or communication connection of devices or units, and may be electrical, mechanical, or other forms.

[0394] The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Components shown as units may or may not be physical units. Some or all of these units may be selected to achieve the objectives of this embodiment as needed.

[0395] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0396] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using a software program, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state drive (SSD)). In the embodiment of the present application, the computer may include the aforementioned device.

[0397] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art can understand and implement other changes to the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0398] Although the present application has been described with reference to specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely illustrative of the present application as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, the present application is intended to include such modifications and variations as fall within the scope of the claims of the present application and their equivalents.

Claims

1. A communication method, characterized in that: The method comprises: Obtain information of multiple candidate cells of a terminal device; Determine that the terminal device is switched to a first candidate cell of a first candidate entity, where the first candidate cell is one of the multiple candidate cells; First information is sent according to the information of the multiple candidate cells, where the first information indicates releasing a second candidate cell, and the second candidate cell is one or more of the multiple candidate cells.

2. The method according to claim 1, characterized in that The obtaining the information of the multiple candidate cells of the terminal device includes: receiving the information of the multiple candidate cells from a source entity.

3. The method according to claim 1 or 2, characterized in that: The sending of the first information includes: The first information is sent to a source entity or a second candidate entity, where the second candidate entity is an entity to which the second candidate cell belongs.

4. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: Sending second information to the terminal device, wherein the second information indicates releasing configuration information of the second candidate cell.

5. The method according to claim 4, characterized in that The sending the second information to the terminal device includes: The configuration information of the first candidate cell is sent to the terminal device, where the configuration information of the first candidate cell includes the second information, and the configuration information of the first candidate cell is used for the terminal device to access the first candidate cell.

6. The method according to claim 1 or 2, characterized in that: The determining that the terminal device is switched to a first candidate cell of the first candidate entity includes: Receive third information from the first candidate entity, where the third information instructs the terminal device to switch to the first candidate cell.

7. The method according to any one of claims 1, 2 or 6, characterized in that: The sending the first information includes: sending the first information to the first candidate entity.

8. The method according to any one of claims 1 to 7, characterized in that: The first information includes at least one of the following: identification information of the second candidate cell, identification information allocated by a source entity to the terminal device, identification information allocated by a second candidate entity to the terminal device, or identification information of a source entity, and the second candidate entity is the entity to which the second candidate cell belongs.

9. The method according to any one of claims 1 to 8, characterized in that: The second candidate cell belongs to a second candidate entity, and the second candidate entity is not the same entity as the first candidate entity.

10. The method according to any one of claims 1 to 9, characterized in that: The information of the multiple candidate cells includes identification information of each of the multiple candidate cells; and sending the first information according to the information of the multiple candidate cells includes: Determine, according to the identification information of each of the multiple candidate cells, to release the second candidate cell; The first information is sent.

11. The method according to any one of claims 2, 3 or 8, characterized in that: The source entity is used to request configuration information of the multiple candidate cells for the terminal device.

12. The method according to claim 11, characterized in that The source entity is a centralized unit CU, a source base station or a master node MN in dual connectivity.

13. The method according to any one of claims 1 to 12, characterized in that: The multiple candidate cells are used to perform at least one of the following: continuous conditional handover CHO, continuous addition or change of conditional primary and secondary cells CPAC, or continuous layer 1 / layer 2 triggered mobility LTM.

14. A communication method, characterized in that: The method comprises: receiving information of a plurality of candidate cells from a source entity; Switching to a first candidate cell of a first candidate entity, where the first candidate cell is one of the multiple candidate cells; First information is sent to the first candidate entity, where the first information indicates releasing a second candidate cell, where the second candidate cell is one or more of the multiple candidate cells.

15. The method according to claim 14, characterized in that The method further includes receiving second information from the source entity, where the second information is used to indicate a condition for releasing the second candidate cell.

16. The method according to claim 15, characterized in that The second information includes information indicating a timer and / or a maximum number of switching times corresponding to the second candidate cell.

17. The method according to claim 15, characterized in that The method further comprises: When the timer times out, it is determined to release the second candidate cell.

18. The method according to claim 16 or 17, characterized in that The method further comprises: When the number of switching to the second candidate cell is greater than or equal to the maximum number of switching, it is determined to release the second candidate cell.

19. The method according to any one of claims 14 to 18, characterized in that: The source entity is a centralized unit CU, a source base station or a master node MN in dual connectivity.

20. The method according to any one of claims 14 to 19, characterized in that: The multiple candidate cells are used to perform at least one of the following: continuous conditional handover CHO, continuous addition or change of conditional primary and secondary cells CPAC, or continuous layer 1 / layer 2 triggered mobility LTM.

21. A communication device, characterized in that: The communication device comprises a processor; the processor is used to run a computer program or instruction so that the communication device executes the method according to any one of claims 1 to 13, or so that the communication device executes the method according to any one of claims 14 to 20.

22. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions or programs. When the computer instructions or programs are executed on a computer, the method according to any one of claims 1 to 13 is executed, or the method according to any one of claims 14 to 20 is executed.

23. A computer program product, characterized in that The computer program product comprises computer instructions; when part or all of the computer instructions are run on a computer, the method according to any one of claims 1 to 13 is executed, or the method according to any one of claims 14 to 20 is executed.

24. A chip, characterized in that: include: a memory for storing computer program instructions; A processor, configured to execute the computer program instructions so that a communication device including the chip performs the method according to any one of claims 1 to 13, or a communication device including the chip performs the method according to any one of claims 14 to 20.

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