Wireless communication method and apparatus

Abstract

Provided are a wireless communication method and an apparatus. The method comprises: a first terminal device receives first information sent by a first CU, the first information being used for indicating a target resource, the target resource being used for the first terminal device to hand over from a first cell to a second cell, and the second cell being a cell within a second CU.

Description

Wireless communication method and device Technical Field

[0001] The present application relates to the field of communication technology, and more specifically, to a wireless communication method and apparatus. Background Art

[0002] The cell handover of the terminal device may be a cell handover within the same centralized unit (CU) or a cell handover across CUs. Currently, there is no clear solution for how the terminal device can implement cell handover across CUs.

[0003] Summary of the Invention

[0004] The present application provides a wireless communication method and apparatus. The following introduces various aspects of the present application.

[0005] In a first aspect, a wireless communication method is provided, including: a first terminal device receives first information sent by a first CU, the first information is used to indicate a target resource, and the target resource is used for the first terminal device to switch from a first cell to a second cell, the first cell is a cell within the first CU, and the second cell is a cell within the second CU.

[0006] According to the second aspect, a terminal device is provided, which is a first terminal device, including: a receiving unit for receiving first information sent by a first CU, the first information is used to indicate a target resource, and the target resource is used for the first terminal device to switch from a first cell to a second cell, the first cell is a cell within the first CU, and the second cell is a cell within the second CU.

[0007] In a third aspect, a terminal device is provided, which is a first terminal device, including a processor, a memory, and a communication interface, the memory being used to store one or more computer programs, and the processor being used to call the computer program in the memory so that the terminal device executes some or all of the steps in the method of the first aspect.

[0008] In a fourth aspect, an embodiment of the present application provides a communication system, which includes the above-mentioned terminal device and / or network device. In another possible design, the system may also include other devices that interact with the terminal device or network device in the solution provided in the embodiment of the present application.

[0009] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and the computer program enables a communication device (for example, a terminal device or a network device) to execute some or all of the steps in the methods of the above aspects.

[0010] In a sixth aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a communication device (e.g., a terminal device or a network device) to perform some or all of the steps of the methods described in each of the above aspects. In some implementations, the computer program product may be a software installation package.

[0011] In the seventh aspect, an embodiment of the present application provides a chip, which includes a memory and a processor. The processor can call and run a computer program from the memory to implement some or all of the steps described in the methods of the above aspects.

[0012] This application indicates the cell resources (i.e., the resources of the second cell) within the target CU (i.e., the second CU in the above text) to the first terminal device through the source CU (i.e., the first CU in the above text), so that the terminal device can switch to the second cell according to the resources of the second cell, thereby realizing cell switching across CUs, and providing a clear solution for cell switching across CUs of terminal devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG1 is a wireless communication system 100 used in an embodiment of the present application.

[0014] FIG2 is a schematic flowchart of a cell handover based on L3.

[0015] FIG3 is a schematic flowchart of a cell handover based on L1 / L2.

[0016] FIG4 is a schematic diagram of a switching scenario provided in an embodiment of the present application.

[0017] FIG5 is a schematic flowchart of a wireless communication method provided in an embodiment of the present application.

[0018] FIG6 is a schematic flowchart of an inter-CU cell switching provided in an embodiment of the present application.

[0019] FIG7 is a schematic flowchart of another cross-CU cell switching provided in an embodiment of the present application.

[0020] FIG8 is a schematic flowchart of another cross-CU cell switching provided in an embodiment of the present application.

[0021] FIG9 is a schematic block diagram of a terminal device provided in an embodiment of the present application.

[0022] FIG10 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] The technical solution in this application will be described below with reference to the accompanying drawings.

[0024] Figure 1 illustrates a wireless communication system 100 used in an embodiment of the present application. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographic area and may communicate with the terminal device 120 within the coverage area.

[0025] FIG1 exemplarily shows a network device and two terminals. Optionally, the wireless communication system 100 may include multiple network devices and each network device may include other numbers of terminal devices within its coverage area, which is not limited in the embodiments of the present application.

[0026] Optionally, the wireless communication system 100 may further include other network entities such as a network controller and a mobility management entity, which is not limited in the embodiment of the present application.

[0027] It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), etc. The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, satellite communication system, etc.

[0028] The terminal device in the embodiments of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiments of the present application may refer to a device that provides voice and / or data connectivity to a user and can be used to connect people, objects and machines, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. Optionally, the UE can be used to act as a base station. For example, the UE can act as a scheduling entity that provides sidelink signals between UEs in V2X or D2D, etc. For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and smart home devices communicate without relaying the communication signal through the base station.

[0029] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. A base station can broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmission point (TRP), transmission point (TP), master station MeNB, secondary station SeNB, multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), CU, distributed unit (DU), positioning node, etc. A base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. A base station can also refer to a communication module, modem or chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs base station functions in device-to-device D2D, vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. The base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form used by the network equipment.

[0030] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0031] In some deployments, the network device in the embodiments of the present application may refer to a CU or a DU, or the network device includes a CU and a DU. The gNB may also include an AAU.

[0032] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0033] It should be understood that all or part of the functions of the communication device in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (such as a cloud platform).

[0034] Cell handover (HO) aims to improve the continuity of service provided by the communication system to terminal devices. In a wireless communication system, when a terminal device moves from one cell (also known as the "source cell") to another, in order to maintain communication, the terminal device needs to hand over to the other cell (also known as the "target cell"). The cell can be a primary cell (PCell) or a primary secondary cell (PSCell).

[0035] The cell switching in the embodiment of the present application can be a traditional switching mechanism or a conditional switching mechanism.

[0036] In a traditional handover mechanism, to improve the continuity of services provided by the communication system to connected terminal devices, the network device will send a handover command to the terminal device at an appropriate time (for example, when the signal measurement result of the terminal device in the serving cell falls below a threshold) to instruct the terminal device to perform a cell handover. In some implementations, the handover command may be a radio resource control (RRC) reconfiguration message containing synchronization reconfiguration information.

[0037] For the conditional handover (CHO) mechanism, the network device can configure the configuration of one or more candidate cells and the conditional handover events associated with one or more candidate cells to the terminal device. The conditional handover event can also be called the conditional handover trigger condition. Accordingly, the terminal device can determine whether the conditional handover event is met based on the signal measurement results of the candidate cell. If the terminal device determines that a candidate cell meets the conditional handover event, the terminal device can initiate random access to the candidate cell.

[0038] FIG2 is a schematic flowchart of an L3-based cell switching provided in an embodiment of the present application.

[0039] Referring to FIG. 2 , in step S210 , the terminal device sends an L3 measurement report to the source cell.

[0040] In step S220, the source cell determines that the terminal device performs cell handover based on the layer 3 (L3) measurement report. The source cell may also select a target cell for the terminal device.

[0041] In step S230, the source cell sends a handover request to the target cell.

[0042] In step S240, the target cell sends a handover request response to the source cell.

[0043] In step S250, the source cell sends an L3 handover command to the terminal device.

[0044] In step S260, after receiving the L3 handover command, the terminal device establishes a connection with the target cell.

[0045] For L3 handover, the source cell does not make any preparations before confirming the handover. After confirming the handover, it starts communicating with the target cell to prepare for the handover. The source cell can then notify the terminal device so that the terminal device can access the target cell. L3-based cell handover is triggered by L3 measurement and completed through RRC signaling. L3-based handover requires reconfiguration of the RRC layer or the packet data convergence protocol (PDCP) layer, and resets the medium access control (MAC) layer and / or the physical layer, which increases the complexity of the handover process and increases the handover delay. Therefore, the LTM mechanism is introduced. LTM uses L1 / L2 signaling to implement changes in the service cell of the terminal device while maintaining the high-level configuration unchanged, which helps to reduce delays, reduce overhead and shorten interruption time.

[0046] The following describes the L1 / L2-based cell handover process in conjunction with FIG3 .

[0047] In step S310, the target cell sends first configuration information to the source cell. The first configuration information is used to configure resources of the target cell. The resources of the target cell are used by the terminal device to switch to the target cell. The first configuration information can also be referred to as the configuration information of the target cell.

[0048] The resources of the target cell may include one or more of the following: cell-radio network temporary identifier (C-RNTI), configured grant (CG), control-resource set (CORESET), preamble, physical random access channel (PRACH) opportunity, etc.

[0049] In step S320, the source cell sends second configuration information to the terminal device. The second configuration information includes the first configuration information.

[0050] In step S330, the terminal device obtains the timing advance (TA) of the target cell based on the second configuration information.

[0051] In step S340, the terminal device sends an L1 measurement report to the source cell.

[0052] In step S350, the source cell sends an L1 handover command to the terminal device.

[0053] In step S360, the terminal device uses CG to send uplink data to the target cell.

[0054] In step S370, the target cell sends uplink resource allocation to the terminal device.

[0055] In step S380, the terminal device searches for downlink control information (DCI) according to the configuration of the search space, obtains a dynamic grant (DG), and uses the DG to send uplink data to the target cell.

[0056] In step S390, the target cell sends a handover response to the terminal device.

[0057] As shown in Figure 3, for L1 / L2 handover, the source cell communicates with one or more target cells before the handover occurs. The target cells allocate resources for the terminal device to use for the handover and notify the terminal device of these configurations. The terminal device can obtain the TA value of one or more target cells. When the handover conditions are met, the source cell notifies the terminal device to switch to a qualified target cell through an L1 handover command.

[0058] There are two ways for a terminal device to access a target cell, and these two ways are introduced below. Method one, if the target cell allocates CG resources for the terminal device, the terminal device can send uplink data to the target cell through the CG resources, as described in step S360. Method two, if the target cell does not allocate CG resources for the terminal device, the terminal device can monitor the physical downlink control channel (PDCCH) of the target cell to obtain the uplink resources dynamically allocated to the terminal device. The terminal device can send uplink data to the target cell through dynamic uplink resources, as described in steps S370 and S380.

[0059] After the target cell receives the uplink data sent by the terminal device, it can send a switching response to the terminal device. At this point, the L1 / L2 switching process ends.

[0060] Compared to the L3 handover process, the L1 / L2 handover process places a significant amount of preparatory work before the handover occurs. Once the radio conditions triggering the handover are met and the source cell receives the L1 handover command, the terminal device can use the previously acquired TA and uplink resources to send uplink data to the target cell. As a result, the time from "handover conditions being met" to "handover completion" is shortened, reducing handover latency.

[0061] Figure 3 shows three different handover scenarios. In Figure 3 (a), the source cell and the target cell both belong to the same DU and the same CU. This handover is called intra-CU cell handover. In Figure 3 (b), the source cell and the target cell belong to different DUs, but the source cell and the target cell belong to the same CU. This handover is called intra-CU cell handover. In Figure 3 (c), the source cell and the target cell belong to different DUs and different CUs. This handover is called inter-CU cell handover.

[0062] At present, the cell switching process is only applicable to cell switching under the same CU, that is, the source cell and the target cell are controlled by the same CU. That is, the current switching process is only applicable to the scenarios shown in Figure (a) and Figure (b) in Figure 3. For the scenarios shown in Figure (a) and Figure (b) in Figure 3, taking L1 / L2 switching as an example, the C-RNTI allocation, CG allocation, etc. involved in the switching are all performed by the control function within the CU. If the cell switching occurs within the CU, the C-RNTI allocation, CG allocation and other behaviors all occur within the same CU, and the CU can allocate resources to the terminal device in multiple quasi-target cells. As long as the terminal device accesses a target cell, the CU can immediately delete the resources allocated to the terminal device in other quasi-target cells. However, there is currently no clear solution for the cross-CU switching described in Figure (c) in Figure 3.

[0063] Based on this, an embodiment of the present application provides a wireless communication method, which indicates the cell resources (i.e., the resources of the second cell) within the target CU (i.e., the second CU) to the first terminal device through the source CU (i.e., the first CU), so that the terminal device can switch to the second cell according to the resources of the second cell, thereby realizing cell switching across CUs, and providing a clear solution for cell switching across CUs for terminal devices.

[0064] The wireless communication method provided in the embodiment of the present application is described in detail below with reference to FIG5 .

[0065] Referring to Figure 5, in step S510, a first terminal device receives first information sent by a first CU. There may be multiple terminal devices within the first CU, and the first terminal device is one of the multiple terminal devices. A terminal device within the first CU may refer to a terminal device connected to the first CU or a terminal device communicating with the first CU.

[0066] In some implementations, the first CU may be a CU corresponding to a serving cell of the terminal device. The first CU may also be referred to as a CU of a source cell or a CU of a serving cell.

[0067] In some embodiments, the first information may be used to indicate a target resource. The target resource may be used for handover of the first terminal device from the first cell to the second cell. In some embodiments, the target resource may also be referred to as a resource of the second cell. In some embodiments, the first cell may be referred to as a serving cell or a source cell, and the second cell may be referred to as a target cell or a quasi-target cell.

[0068] In some embodiments, the target resources may include resources used for cell handover. For example, the target resources may include resources that can be used for random access. In some embodiments, the target resources may include resources used by the terminal device to communicate with the second cell. The terminal device may access the second cell and / or communicate with the second cell through the target resources.

[0069] The embodiments of the present application do not specifically limit the type of target resources. In some embodiments, the target resources may include one or more of the following: C-RNTI, CG, CORESET, preamble, PRACH timing, key, key-related parameters, etc. In some embodiments, since both CG and CORESET can be used for the first terminal device to transmit uplink data, the target resource can include one of the CG and CORESET. That is, the target resource may include one or more of the following: C-RNTI, CG, preamble, PRACH timing, key; or, the target resource may include one or more of the following: C-RNTI, CORESET, preamble, PRACH timing, key. Among them, the preamble and PRACH timing can be used for random access by the first terminal device. C-RNTI, CG, CORESET and key can be used for the first terminal device to communicate with the second cell.

[0070] C-RNTI can be used to identify the first terminal device. Through C-RNTI, the network device can uniquely identify the first terminal device.

[0071] CG resources can be used for the first terminal device to transmit uplink data.

[0072] CORESET can be used by the first terminal device to receive the PDCCH or DCI sent by the second cell, and obtain the DG through the PDCCH or DCI to transmit uplink data through the DG.

[0073] The preamble and PRACH opportunity may be used for random access by the first terminal device. The first terminal device may send a preamble to the second cell, thereby initiating a random access procedure.

[0074] The key can be used to encrypt the communication data between the first terminal device and the second cell to ensure the security of the communication. The key can be, for example, a key for integrity verification. Key-related parameters can be used to generate the key. In some embodiments, the key can be generated by the first CU, and the first CU can send the key to the first terminal device and the second CU, so that the first terminal device and the second CU can communicate based on the key. In some embodiments, the key can also be generated by the first terminal device. The first CU can send the parameters for generating the key to the first terminal device, and the first terminal device can generate the key based on the parameters and the agreed algorithm. The first CU can also generate the key in the same way as the first terminal device and send the key to the second CU. In this way, the first terminal device and the second CU can communicate based on the same key.

[0075] The embodiment of the present application does not specifically limit the carrying manner of the first information. In some implementations, the first information may be carried in one message, or the first information may be carried in multiple messages. For example, the first information may be carried in a handover configuration message, and the first CU may indicate the target resource to the first terminal device through the handover configuration message. For another example, the first information may be carried in a handover command, and the first CU may indicate the target resource to the first terminal device through the handover command. For another example, the first information may be carried in a handover configuration message and a handover command, and the first CU may indicate part of the target resource to the first terminal device through the handover configuration message, and indicate another part of the target resource to the first terminal device through the handover command.

[0076] In some embodiments, the second cell may be a cell within the second CU. The second CU is different from the first CU. The process of switching the terminal device from the first cell to the second cell may also be referred to as inter-CU switching. Of course, in some embodiments, the second cell may also be a cell within the first CU, which is not specifically limited in the embodiments of the present application.

[0077] The embodiments of the present application do not specifically limit the manner in which the first terminal device performs cell switching. In some implementations, the first terminal device can perform L3 switching. That is, the first terminal device can switch to the second cell via L3 switching. In some implementations, the first terminal device can perform L1 / L2 switching. That is, the first terminal device can switch to the second cell via L1 / L2 switching. L1 / L2 switching can reduce the switching latency of the first terminal device.

[0078] The target resource may be acquired by the first CU. The embodiment of the present application does not specifically limit the manner in which the first CU acquires the target resource. As an example, the target resource may be configured by the second CU to the first CU. As another example, the target resource may be selected by the first CU from a resource pool. The resource pool may include resources reserved by the second cell for the terminal device in the first CU. The following describes these two methods respectively.

[0079] The following first introduces the method of allocating target resources from the second CU to the first CU.

[0080] In some implementations, the second CU may send first configuration information to the first CU, where the first configuration information may include configuration information of the target resource. After receiving the first configuration information, the first CU may forward or transparently transmit the first configuration information to the first terminal device. In this case, the first configuration information is the first information.

[0081] In some implementations, the first CU may send a request message to the second CU, where the request message may be used to request a target resource. After receiving the request message, the second CU may send the target resource to the first CU. In some embodiments, the request message may be a handover request message. The handover request message may be used by the second CU to prepare for the handover.

[0082] In some implementations, the first CU may send a request message to the second CU when the first terminal device meets a triggering condition. The triggering condition may be a condition for triggering an LTM process.

[0083] In some implementations, whether the first terminal device meets the triggering condition can be determined based on a measurement report. The measurement report can be sent by the first terminal device to the first CU. The measurement report can be an L3 measurement report. The first CU can determine whether to initiate an LTM process based on the measurement report.

[0084] In some implementations, the first information may be used to indicate resources of one or more cells. These one or more cells may also be referred to as quasi-target cells. Taking the example of the first information being used to indicate resources of multiple cells, the resources of the multiple cells may be used for handover of the first terminal device to the multiple cells. For example, the multiple cells include a second cell and a third cell. The resources of the second cell may be used for handover of the first terminal device to the second cell, and the resources of the third cell may be used for handover of the first terminal device to the third cell.

[0085] The embodiments of the present application do not specifically limit the multiple cells. In some implementations, the CUs corresponding to the multiple cells may be the same or different. In some implementations, the multiple cells may include cells within one CU or cells within multiple CUs. For example, the multiple cells may include cells within the second CU. For another example, the multiple cells may include cells within the first CU and cells within the second CU. For another example, the multiple cells may include cells within the first CU, cells within the second CU, and cells within the third CU.

[0086] In some implementations, if a first terminal device switches to a second cell among multiple cells, resources in other cells among the multiple cells may be released, and the released resources may be used by other terminal devices, thereby improving resource utilization. For example, the multiple cells include a second cell, a third cell, and a fourth cell. After the first terminal device switches to the second cell, resources in the third and fourth cells may be released.

[0087] In some implementations, if the third cell is a cell within the first CU, the first CU may release resources of the third cell, or in other words, the resources of the third cell may be released by the first CU.

[0088] In some implementations, the first CU may release the resources of the second cell upon receiving the third indication information sent by the second CU. The third indication information may be used to instruct the first terminal device to switch to the second cell. For example, after the first terminal device successfully switches to the second cell, the second CU may send the third indication information to the first CU to indicate that the first terminal device has successfully switched to the second cell. After receiving the third indication information, the first CU may release the resources of the third cell.

[0089] In some implementations, the third indication information may include an identifier of the first terminal device so that the first CU can determine which terminal device successfully accesses the second cell. The identifier of the first terminal device may be the C-RNTI corresponding to the first terminal device. For example, the second CU may indicate to the first CU that "UE access with C-RNTI XXX is successful." In some embodiments, the C-RNTI corresponding to the first terminal device may be allocated to the first terminal device by a cell within the first CU, or may be allocated to the first terminal device by a cell within the second CU.

[0090] In some embodiments, if the fourth cell is a cell within the third CU, the third CU may release resources of the fourth cell, or in other words, the resources of the fourth cell may be released by the third CU.

[0091] In some implementations, the third CU may release resources of the fourth cell upon receiving the fourth indication information. The fourth indication information may be used to instruct the first terminal device to switch to the second cell. The fourth indication information may be sent by the first CU to the third CU. For example, after the second CU instructs the first CU first terminal device to switch to the second cell, the first CU may send the fourth indication information to the third CU.

[0092] In some implementations, the fourth indication information may include an identifier of the first terminal device so that the third CU can determine which terminal device successfully accesses the second cell. The identifier of the first terminal device may be the C-RNTI corresponding to the first terminal device. For example, the first CU may indicate to the third CU that "UE access with C-RNTI XXX is successful." In some embodiments, the C-RNTI corresponding to the first terminal device may be allocated to the first terminal device by a cell within the first CU, or may be allocated to the first terminal device by a cell within the third CU.

[0093] In some implementations, the second CU may send third indication information to the first CU when determining that the cell switching performed by the first terminal device is an inter-CU cell switching. In some embodiments, the second CU may determine whether the cell switching performed by the first terminal device is an inter-CU cell switching based on the C-RNTI of the first terminal device. In some embodiments, the second CU may determine whether the cell switching performed by the first terminal device is an inter-CU cell switching based on the resource location used by the first terminal device to access the second cell. The resource location may include a CG resource location.

[0094] The following describes how the first CU obtains target resources from the resource pool.

[0095] In some implementations, the resource pool is a public resource pool. This means that the resources in the resource pool are public. The resources in the resource pool do not belong to any terminal device, and any terminal device can use the resources in the resource pool for cell handover. By selecting resources from the resource pool for cell handover, the interaction load between CUs can be greatly reduced, simplifying the handover process.

[0096] In some implementations, the resource pool may include resources of one or more cells. The one or more cells may also be referred to as quasi-target cells. Taking the resource pool including resources of multiple cells as an example, the resources of multiple cells may be used for the first terminal device to switch to multiple cells respectively. For example, the multiple cells include a second cell and a third cell, and the resources of the second cell may be used for the first terminal device to switch to the second cell, and the resources of the third cell may be used for the first terminal device to switch to the third cell. In some implementations, the resource pool includes resources reserved by multiple cells in the second CU for the terminal device in the first CU.

[0097] The embodiments of the present application do not specifically limit the multiple cells. In some implementations, the CUs corresponding to the multiple cells may be the same or different. In some implementations, the multiple cells may include cells within one CU or cells within multiple CUs. For example, the multiple cells may include cells within the second CU. For another example, the multiple cells may include cells within the first CU and cells within the second CU. For another example, the multiple cells may include cells within the first CU, cells within the second CU, and cells within the third CU.

[0098] In some implementations, different CUs may correspond to different resource pools. Taking the second and third CUs as an example, the resource pool provided by the second CU is resource pool 1, and the resource pool provided by the third CU is resource pool 2. The resources in resource pool 1 can be used for terminal devices in the first CU to switch to a cell in the second CU, and the resources in resource pool 2 can be used for terminal devices in the first CU to switch to a cell in the third CU.

[0099] In some implementations, the resources in the resource pool are resources dedicated to cell handover.

[0100] In some implementations, the resource pool may include resources allocated by CUs to each other's terminal devices. Taking the first CU and the second CU as an example, the resource pool may include resources allocated by the first CU to the terminal devices in the second CU, and resources allocated by the second CU to the terminal devices in the first CU. Of course, in some implementations, the resource pool may also include resources allocated by the CU to the terminal devices in it. Taking the first CU and the second CU as an example, the resource pool may include resources allocated by the first CU to the terminal devices in the first CU, and resources allocated by the second CU to the terminal devices in the second CU.

[0101] In some implementations, the resources allocated by the first CU to the terminal devices within the first CU may be the same as or different from the resources allocated by the first CU to the terminal devices within the second CU. This embodiment of the present application does not specifically limit this.

[0102] In some implementations, resources in the resource pool may be allocated at a cell granularity. Allocating resources at a cell granularity may improve resource utilization. For example, the resource pool may include resources of a second cell, and the resources of the second cell may be used by any terminal device (e.g., any terminal device within the first CU) to switch to the second cell for use.

[0103] The resource types reserved by multiple cells for terminal devices in the first CU may be the same, or the resource types reserved by multiple cells for terminal devices in the first CU may be different, and the embodiments of the present application do not specifically limit this. As an example, the resources reserved by cell 1 may include resources for random access (such as preamble, PRACH opportunity, etc.), and the resources reserved by cell 2 may include resources for transmitting uplink data (such as CG, CORESET, C-RNTI, key, etc.). As another example, the resources reserved by cell 3 for transmitting uplink data include CG, and the resources reserved by cell 4 for transmitting uplink data include CORESET.

[0104] For example, the resources provided by cell 1 include CG, which is used by the terminal device to transmit uplink data. For another example, the resources provided by cell 2 include CORESET, which is used by the terminal device to receive PDCCH or DCI, thereby obtaining DG, and transmitting uplink data through DG.

[0105] In some implementations, the target resource may be selected by the first CU from a resource pool. For example, the first CU may select the target resource from resources provided by the second cell.

[0106] Taking the second cell as an example, there are many ways for the second cell to provide resources, which are not specifically limited in the embodiments of the present application. The following describes the ways in which the second cell provides resources.

[0107] In some implementations, the resources provided by the second cell may include multiple sets of resources, and each set of resources may include multiple types of resources. In other words, different types of resources have fixed combinations. Taking C-RNTI, CG, CORESET, preamble, and PRACH opportunity as an example, the first set of resources may include C-RNTI-1, CG-1, CORESET-1, preamble-1, and PRACH opportunity-1, and the second set of resources may include C-RNTI-2, CG-2, CORESET-2, preamble-2, and PRACH opportunity-2, and so on. When the first CU performs resource selection, it can select a set of resources from multiple sets of resources for the first terminal device to perform cell switching.

[0108] In some implementations, the resources provided by the second cell may include resource sets for different types of resources, and the first CU may arbitrarily combine the resources provided by the second cell. For example, the resources provided by the second cell include a C-RNTI set, a CG set, a CORESET set, a preamble set, and a PRACH opportunity set. When selecting the target resource, the first CU may select a C-RNTI from the C-RNTI set, a CG from the CG set, a CORESET from the CORESET set, a preamble from the preamble set, a PRACH from the PRACH opportunity set, etc. The first CU may combine the selected resources to form the target resource.

[0109] In some embodiments, the target resource includes a second resource, the second resource belongs to a first type of resource, the second resource is a resource selected by the first CU from a first resource set, and the first resource set is a first type of resource reserved by the second cell for a terminal device in the first CU. Taking the first type of resource as a C-RNTI as an example, the first CU can select a C-RNTI from the C-RNTI set for the first terminal device to switch to the second cell.

[0110] In some implementations, the first terminal device may use target resources in the resource pool to switch to the second cell. After the first terminal device switches from the first cell to the second cell, a first resource in the target resource satisfies any of the following conditions: the first resource is released and used for other terminal devices in the first CU to switch to the second cell; the first resource cannot be used for other terminal devices in the first CU to switch to the second cell; or the first resource is used for communication between the first terminal device and the second cell.

[0111] In some implementations, the first resource includes some or all of the target resources. In some implementations, the first resource may include one or more of the following: a C-RNTI, a CG, a CORESET, a preamble, a PRACH opportunity, a key, or key-related parameters. For example, the first resource may include a C-RNTI.

[0112] In some implementations, after the first terminal device switches to the second cell, the first resource in the target resource may be released. The first resource may include some or all of the target resource. The released resource can be used by other terminal devices, thereby improving resource utilization.

[0113] For example, the first resource may include a first C-RNTI, and the first terminal device may use the first C-RNTI to switch to the second cell. After the first terminal device uses the first C-RNTI to switch to the second cell, the first C-RNTI may be released, and the released first C-RNTI can be used by other terminal devices.

[0114] In some embodiments, after releasing the first C-RNTI, the first terminal device may receive a second C-RNTI sent by the second cell. The second C-RNTI may be used by the first terminal device to communicate with the second cell after accessing the second cell.

[0115] In some implementations, before receiving the second C-RNTI, the first terminal device may first determine whether the target resource is a dedicated resource of the first terminal device. The first terminal device determines whether the target resource is a dedicated resource of the first terminal device, which can also be understood as the first terminal device determining whether the target resource is a public resource. If the target resource is a dedicated resource, it means that the target resource does not belong to a public resource; if the target resource is not a dedicated resource, it means that the target resource belongs to a public resource. In some embodiments, if the target resource is a dedicated resource, the first terminal device can continue to use the target resource (such as the first C-RNTI) after switching to the second cell, that is, the target resource will not be released; if the target resource is a public resource, the first terminal device can release the first resource in the target resource (such as the first C-RNTI) and receive the second C-RNTI sent by the second cell, or wait for the second cell to reallocate the C-RNTI.

[0116] In some implementations, after the first terminal device switches from the first cell to the second cell, the first resource in the target resource cannot be used by other terminal devices, or in other words, the first resource in the target resource cannot be used by other terminal devices in the first CU to switch to the second cell. This can avoid major changes to the existing protocol. Taking the terminal devices in the first CU including terminal device 1 and terminal device 2 as an example, after terminal device 1 switches to the second cell, the first resource in the target resource will not be used for terminal device 2 to switch to the second cell. If the first CU needs to allocate resources for terminal device 2, it can select from other resources in the resource pool except the first resource.

[0117] In some implementations, after the first CU allocates resources to the terminal device, the resources in the resource pool will be reduced. Taking the first resource as an example, after the first terminal device uses the first resource to switch to the second cell, or in other words, after the first CU allocates the first resource to the first terminal device, the first resource can be deleted from the resource pool.

[0118] In some implementations, after the first terminal device switches to the second cell, the first resource in the target resource can be used for communication between the first terminal device and the second cell. That is, the first resource can also be used for subsequent data transmission between the first terminal device and the second cell. In this case, the first resource cannot be used for other terminal devices in the first CU to switch to the second cell.

[0119] As an example, the first resource may include a third C-RNTI. After the terminal device switches to the second cell using the third C-RNTI, it can continue to use the third C-RNTI to communicate with the second cell. In this way, after the handover is completed, the second cell does not need to re-allocate a new C-RNTI to the first terminal device, which can reduce changes to the existing protocol (in the existing protocol, the replacement of the C-RNTI is only involved during the handover process).

[0120] For example, after the first terminal device switches to the second cell, it can continue to use the third C-RNTI, and the C-RNTI in the resource pool will be reduced. However, other resources in the resource pool, such as the CG, CORESET, preamble, and PRACH opportunity, will not be reduced and can still be used by other terminal devices that are switching.

[0121] As another example, the first resource may include C-RNTI, CG, CORESET, preamble, and PRACH opportunity. For example, after the first terminal device switches to the second cell, it can continue to use the third C-RNTI, and the C-RNTI in the resource pool will be reduced. Other resources will also be reduced, such as CG, CORESET, preamble, PRACH opportunity, etc. In other words, the resources used by the first terminal device cannot be used by the terminal device that switches subsequently.

[0122] In some implementations, the first CU may send second indication information to the first terminal device, where the second indication information is used to indicate whether the first resource can be used for communication between the first terminal device and the second cell, or the second indication information is used to indicate whether the first resource can be used for other terminal devices within the first CU to switch to the second cell. It is understandable that if the first resource can be used for communication between the first terminal device and the second cell, it means that the first resource cannot be used for other terminal devices within the first CU to switch to the second cell.

[0123] In some implementations, the second CU may notify the first CU whether the first resource can continue to be used. For example, the second CU may send indication information to the first CU to indicate whether the first resource (such as C-RNTI) can continue to be used, or to indicate which resources can continue to be used and which resources cannot continue to be used. If the first resource can continue to be used, the first terminal device can continue to use the first resource to communicate with the second cell after accessing the second cell.

[0124] There are many ways to carry the second indication information, which are not specifically limited in the embodiments of the present application. For example, the second indication information can be carried in the first information. For another example, the first indication information can be carried in the handover command.

[0125] In some implementations, if the target resource is a dedicated resource for the first terminal device, the first resource cannot be used for other terminal devices in the first CU to switch to the second cell. In some implementations, if the target resource is not a dedicated resource for the first terminal device, the first resource in the target resource can be released, and the first resource can be used for other terminal devices in the first CU to switch to the second cell. In some implementations, if the target resource is not a dedicated resource for the first terminal device, the first resource cannot be used for other terminal devices in the first CU to switch to the second cell. In some implementations, if the target resource is not a dedicated resource for the first terminal device, the first resource can be used for subsequent communications between the first terminal device and the second cell.

[0126] In some implementations, the first terminal device may receive a first message sent by the first CU to determine whether the target resource is a dedicated resource of the first terminal device.

[0127] In some implementations, whether the target resource is a dedicated resource for the first terminal device may be determined based on the type of the second cell.

[0128] The type of the second cell may include a cell in which the second cell belongs to the first CU, and a cell in which the second cell does not belong to the first CU (such as a cell in the second CU). If the second cell does not belong to the cell in the first CU, the target resource is a public resource; if the second cell belongs to the cell in the first CU, the target resource is a dedicated resource.

[0129] In some implementations, the first message may include first indication information, where the first indication information is used to indicate the type of the second cell. The type of the second cell may be used to determine whether the target resource is a dedicated resource for the first terminal device. In other words, the first terminal device may determine whether the target resource is a dedicated resource for the first terminal device based on the type of the second cell.

[0130] In some implementations, the resource type included in the first resource can be determined by the first CU, or can also be determined by the second CU, or can also be predefined by the protocol, and the embodiments of the present application do not make specific limitations.

[0131] The embodiment of the present application does not specifically limit the manner in which the first CU indicates the cell type. As an example, the first CU may indicate the cell type in an explicit manner. As another example, the first CU may indicate the cell type in an implicit manner. In other words, the first message may indicate whether the target resource is a dedicated resource of the first terminal device in an implicit manner. In some implementations, the first message may be a message carrying the first information, or the first information is carried in the first message. These two methods are introduced below.

[0132] In some implementations, the first CU may explicitly indicate the type of the cell. For example, the first CU may send first indication information to the first terminal device, or in other words, the first message may include the first indication information, and the first indication information may be used to indicate whether the second cell is a cell within the first CU.

[0133] There are many ways to indicate the first indication information, and the embodiments of the present application do not specifically limit this. For example, the first indication information includes a first bit, and the value of the first bit can be used to indicate whether the second cell is a cell within the first CU. In other words, whether the second cell is a cell within the first CU is determined based on the value of the first bit in the fourth indication information. When the value of the first bit is 0, it indicates that the second cell belongs to a cell within the first CU; when the value of the first bit is not 0 (such as 1), it indicates that the second cell belongs to a cell across CUs. Alternatively, when the value of the first bit is not 0 (such as 1), it indicates that the second cell belongs to a cell within the first CU; when the value of the first bit is 0, it indicates that the second cell belongs to a cell across CUs. The number of bits contained in the first bit can be 1 or more.

[0134] For example, the first CU may indicate a cell list to the first terminal device, and use one bit for each cell to indicate whether the cell is a cell within the first CU. Table 1 shows the correspondence between three cells and the types of the three cells.

[0135] Table 1

[0136] As shown in Table 1, the value of the first bit corresponding to cell 1 is 0, indicating that cell 1 is a cell within the first CU. The value of the first bit corresponding to cell 2 is 1, indicating that cell 2 is a cell across CUs. The value of the first bit corresponding to cell 3 is 0, indicating that cell 3 is a cell within the first CU.

[0137] In some implementations, the first CU may indicate the type of cell in an implicit manner. As an example, whether the first CU is a cell within the first CU may be determined based on the resource type contained in the target resource. For example, if the target resource includes resources of the target type, it indicates that the second cell belongs to a cell across CUs; ​​if the target resource does not include resources of the target type, it indicates that the second cell belongs to a cell within the first CU. The target type resource may be key-related information. Of course, the target type resource may also be other types of resources, which is not specifically limited in the embodiments of the present application. Key-related information may include key and / or key-related parameters. Key-related parameters are used to generate keys.

[0138] Table 2 shows a correspondence between cells and resource configurations.

[0139] Table 2

[0140] It can be seen from Table 2 that since the resource configuration of cell 1 and cell 2 includes key-related information, cell 1 and cell 2 belong to cross-CU cells. Since the resource configuration of cell 3 does not include key-related information, cell 3 belongs to the cell within the first CU.

[0141] In some implementations, the first CU may further indicate first key-related parameters to the first terminal device. The first terminal device may generate a first key based on the first key-related parameters. The first key may be used for communication between the first terminal device and the second cell. For example, the first key may be used to encrypt communication data between the first terminal device and the second cell. In some embodiments, the first key may be derived from a key between the first terminal device and the first cell. Generating the first key by the first CU may increase the security of communication between the first terminal device and the second cell.

[0142] In some implementations, the first key-related parameter is carried in the handover command.

[0143] In some implementations, the first terminal device obtains the type of the second cell. The first terminal device may determine whether to update the key based on the type of the second cell. If the second cell is within the first CU, the first terminal device does not need to update the key. If the second cell is within the second CU, the first terminal device updates the key.

[0144] If the first terminal device needs to update the key, the first terminal device can update the key based on the key-related parameters configured by the first CU and the previously used key. For example, the first terminal device can generate an updated key based on the previously used key, key-related parameters, and a preset algorithm.

[0145] In some implementations, the parameters of the first CU configuration may be carried in the switching configuration information and / or the switching command.

[0146] In some implementations, as described above, after the first terminal device uses the first resource, the first resource in the resource pool will be reduced. In this case, the second CU can allocate the first resource again to meet the needs of subsequent terminal device switching.

[0147] There are many ways for the second CU to allocate resources, which are not specifically limited in the embodiments of the present application. For example, the second CU can periodically allocate the first resource. For another example, the second CU can allocate the first resource again when the number of resources in the resource pool is less than or equal to a preset threshold.

[0148] In some implementations, when configuring resources of multiple cells to the first terminal device, the first CU may also indicate the types of the multiple cells to the first terminal device. The cell types may include cells belonging to the first CU and cells not belonging to the first CU. For example, the first CU may indicate to the first terminal device which cells belong to the cells within the first CU and which cells do not belong to the cells within the first CU. By indicating the type of cell to the first terminal device, the first terminal device can select a cell to access based on the type of cell. For example, the terminal device may give priority to accessing a cell within the first CU, or in other words, the first terminal device may give priority to switching cells within the CU to reduce the complexity of switching.

[0149] The following uses L1 / L2 switching as an example, combined with three specific examples, to elaborate on the solutions of the embodiments of the present application. It should be noted that the following three examples are merely for ease of understanding and should not limit the embodiments of the present application to these examples. In addition, if there is no conflict, the solutions of the following three examples can be combined with each other.

[0150] Example 1

[0151] Example 1 describes a solution in which the target CU instructs the source CU to switch resources.

[0152] Referring to FIG. 6 , in step S602 , the UE sends an L3 measurement report to the source CU.

[0153] After receiving the L3 measurement report, the source CU may determine one or more quasi-target cells according to the L3 measurement report.

[0154] In step S604, the source CU sends a handover preparation request to the target CU. If one or more quasi-target cells are quasi-target cells that cross CUs, the source CU may request handover preparation from the target CU. The source CU may indicate the identifiers of one or more target cells to the target CU.

[0155] In step S606, the target CU indicates resources in one or more quasi-target cells to the source CU. If the target CU allows the UE to access, it can allocate resources to the UE in one or more quasi-target cells and notify the source CU of the corresponding resources.

[0156] In step S608, the source CU sends a handover configuration to the UE. The handover configuration is used to configure resources in one or more quasi-target cells.

[0157] In the set of multiple quasi-target cells, all quasi-target cells may be provided by the same target CU, or may be provided by multiple target CUs, or some quasi-target cells may be provided by the target CU and some may be provided by the source CU.

[0158] The source CU may send the handover configuration to the UE via an RRC message, or send the handover configuration to the UE in the form of a MAC CE via the DU.

[0159] The source CU may inform the UE of which quasi-target cells belong to cells across CUs and which quasi-target cells belong to cells of the same CU.

[0160] In some implementations, the source CU can explicitly notify the UE of the type of the quasi-target cell. For example, the source CU can notify the UE of the type of the quasi-target cell using a bit in the cell list. If the value of this bit is 1, it indicates that the quasi-target cell is a cell of the same CU as the source cell; if the value of this bit is 1, it indicates that the quasi-target cell is a cell that spans multiple CUs.

[0161] In some implementations, the source CU may implicitly notify the UE of the type of the quasi-target cell. For example, if the configuration information of the quasi-target cell includes the key* used by the UE in the quasi-standard cell, the UE may consider the quasi-target cell to be a cross-CU cell. If the configuration information of the quasi-target cell does not include the key* used by the UE in the quasi-target cell, the UE may consider the quasi-target cell to be a cell of the same CU as the source cell.

[0162] In step S610, the UE obtains the TA with each quasi-target cell according to the instruction of the source DU (or source cell).

[0163] In step S612, the UE sends an L1 measurement report to the source DU (or source cell) according to the configuration of the source DU (or source cell).

[0164] In step S614, the source DU (or source cell) sends an L1 / L2 handover command to the UE.

[0165] In step S616, the UE accesses the target cell indicated by the source DU (or source cell). Step S616 includes S616a and S616b. In step S616a, the UE sends uplink data to the target DU. In step S616b, the target DU sends a handover confirmation to the UE.

[0166] In step S618, after receiving the uplink data sent by the UE, the target DU may indicate to the target CU that the UE has accessed.

[0167] In step S620, if the target CU determines that the UE belongs to an inter-CU handover, it notifies the corresponding source CU that the UE has successfully accessed.

[0168] In some implementations, the target CU may determine whether the UE is an inter-CU handover UE based on the UE's C-RNTI and / or the resource location used by the UE to access a cell within the target CU.

[0169] In step S622, the target CU may delete resources prepared for the UE in other cells within the target CU. If there is a quasi-target cell within the target CU, the target CU may notify the quasi-target cell to delete the resources allocated to the UE.

[0170] In step S624, the source CU may delete resources allocated for the UE in other cells within the source CU. After receiving notification of the UE's successful access, the source CU may perform the following processing based on the quasi-target cell it previously prepared for the UE: If there is a quasi-target cell within the source CU, the source CU may notify the quasi-target cell to delete the resources allocated for the UE; if there are quasi-target cells in other CUs, the source CU may notify the other CUs to delete the resources prepared for the UE.

[0171] The resources prepared for the UE may include one or more of the following: C-RNTI, CG, CORESET monitoring DG, key*, etc.

[0172] Examples 2 and 3 describe a scheme where the first CU selects handover resources from a resource pool. In Example 2, resources used by a UE can be released for handover by other UEs. In Example 3, resources used by a UE cannot be used by other UEs. Examples 2 and 3 are described below.

[0173] Example 2

[0174] 7 , in step S702 , CUs prepare resources required for handover for each other's UEs, i.e., resources prepared for UEs switching across CUs. In this process, since the handover process has not yet started, there are no source CU or target CU roles.

[0175] Resources allocated to a CU can be allocated at a cell-level granularity. Within a cell, resources allocated can include one or more of the following: C-RNTI, CG, CORESET, preamble, PRACH opportunity, etc. These resources are public and do not belong to any specific UE. If a UE switches across CUs, it can use these resources for access. Upon successful access, the UE releases these resources.

[0176] Figure 7 only shows the solution in which the target CU provides resource information to the source CU so that the UE can switch from a cell within the source CU to a cell within the target CU. It can be understood that the source CU can also provide resources to the target CU so that the UE can switch from a cell within the target CU to a cell within the source CU.

[0177] The resource types provided by each cell can be the same or different. For example, some cells provide resources including CG for UE to transmit uplink data. For example, some cells provide CORESET for UE to obtain DG by receiving PDCCH and transmit uplink data.

[0178] In step S704, the UE sends an L3 measurement report to the source CU.

[0179] In step S706, the source CU sends a handover configuration to the UE. The handover configuration is used to configure resources of one or more quasi-target cells.

[0180] The source CU selects one or more quasi-target cells for the UE based on the L3 measurement report of the UE and allocates resources to the UE. For quasi-target cells across CUs, the resources provided by the source CU come from the public resource pool provided by the target CU in step S702. It should be noted that the source CU can arbitrarily combine the resources within the unified cell provided by the target CU. For example, select a C-RNTI from the C-RNTI pool, select a CG configuration from the CG pool, select a CORESET from the CORESET pool, select a preamble from the preamble pool, select a PRACH from the PRACH opportunity, etc.

[0181] The types of uplink resources provided by the source cell to the UE can vary. For example, some cells may provide resources including CG for the UE to transmit uplink data. For example, some cells may provide CORESET for the UE to obtain DG by receiving PDCCH and thus transmit uplink data.

[0182] In step S708, the UE obtains the TA of each quasi-target cell.

[0183] In step S710 , the UE sends an L1 measurement report to a source DU (or source cell).

[0184] In step S712, the source DU (or source cell) sends an L1 / L2 handover command to the UE. The handover command may include the updated key key* or a parameter for updating the key.

[0185] In some implementations, the UE determines whether the resources it uses are public or dedicated based on the type of the target cell. Specifically, if the target cell is a cell within the CU, the UE considers that its corresponding resources are dedicated. For resource C-RNTI, after the UE switches successfully, it can use the C-RNTI notified in the L1 / L2 switching command to communicate with the target cell. If the target cell is a cell across CUs, the UE considers that its corresponding resources are public. For resource C-RNTI, after the UE switches successfully, it can wait for the target cell to reallocate the C-RNTI.

[0186] The type of the target cell may be indicated by the source CU to the UE. For the specific indication method, please refer to the description of Example 1.

[0187] In step S714, the UE accesses the target cell. Step S714 includes S714a and S714b. In step S714a, the UE sends uplink data to the target DU. In step S714b, the target DU sends a handover confirmation to the UE.

[0188] In step S716, after receiving the uplink data sent by the UE, the target DU may indicate to the target CU that the UE has accessed.

[0189] In step S718, the target CU indicates to the source CU that the UE has successfully accessed. The target CU may send an indication message to the source CU, indicating that the UE has successfully accessed. The indication message may include the UE identifier. The UE identifier may be the C-RNTI corresponding to the UE. For example, the target CU may notify the source CU that "UE with C-RNTI XXX has successfully accessed." The C-RNTI corresponding to the UE may be allocated to the UE by the target cell or by the source cell.

[0190] In step S720, after receiving the indication that the UE has successfully accessed, the source CU may send the UE's new key key* to the target CU.

[0191] In step S722, the target CU reallocates the C-RNTI to the UE, that is, the target CU may send the changed C-RNTI to the UE.

[0192] In Example 2, the resources used for inter-CU communication are shared. Any UE performing an inter-CU handover can use these resources. After use, the corresponding resources are released for use by the next UE performing an inter-CU handover, significantly reducing the inter-CU communication load.

[0193] Example 3

[0194] 8 , in step S802 , CUs allocate resources required for handover to each other's UEs. In this process, since the handover process has not yet started, there are no source CU or target CU roles.

[0195] Resources allocated to a CU can be allocated at a cell-level granularity. Within a cell, resources allocated can include one or more of the following: C-RNTI, CG, CORESET, preamble, PRACH opportunity, etc. These resources are public and do not belong to any specific UE. If a UE switches across CUs, it can use these resources for access. Upon successful access, the UE releases these resources.

[0196] Figure 8 only shows the solution in which the target CU provides resource information to the source CU so that the UE can switch from a cell within the source CU to a cell within the target CU. It can be understood that the source CU can also provide resources to the target CU so that the UE can switch from a cell within the target CU to a cell within the source CU.

[0197] The resource types provided by each cell can be the same or different. For example, some cells provide resources including CG for UE to transmit uplink data. For example, some cells provide CORESET for UE to obtain DG by receiving PDCCH and transmit uplink data.

[0198] In step S802, the target CU may also indicate to the source CU that "the C-RNTI will be used". In some implementations, the source CU may also indicate to the UE that "the C-RNTI will be used". After the UE accesses the cell of the target CU, the target CU will not change the C-RNTI. Unlike the solutions in the related art, when the target CU allocates C-RNTI, it is not allocated for a specific UE, but for the source CU, and then the source CU allocates these C-RNTIs to the specific switched UEs for use. There are two ways to deal with this situation.

[0199] Solution 1: The values ​​in the C-RNTI pool are used continuously after the UE is switched. This means that the number of C-RNTIs in the C-RNTI pool will decrease. Other resources, such as CG, CORESET, and PRACH occasion, remain unchanged and can still be allocated to subsequent UEs that switch.

[0200] Solution 2: The values ​​in the C-RNTI pool are used continuously after the UE switches. This means that the number of C-RNTIs in the C-RNTI pool will decrease, and other resources will also decrease. In other words, resources used by a UE cannot be used by other UEs that switch subsequently, such as CG, CORESET, and PRACH occasions.

[0201] Which of the above processing methods is adopted may be determined by the source CU, or by the target CU, or may be specified by the protocol.

[0202] If solution 1 is used, the C-RNTI pool will become smaller. Therefore, after a period of time, the reserved C-RNTI needs to be reallocated between CUs. If solution 2 is used, after the UE is successfully handed over, the resource pool will become smaller. Therefore, after a period of time, the reserved resource pool needs to be reallocated between CUs.

[0203] After a UE uses a C-RNTI for inter-CU handover, the source cell may inform the UE whether it can continue to use the C-RNTI. The source cell may notify the UE of this information through handover configuration or L1 / L2 handover command.

[0204] In step S804, the UE sends an L3 measurement report to the source CU.

[0205] In step S806, the source CU sends a handover configuration to the UE. The handover configuration is used to configure resources of one or more quasi-target cells.

[0206] The source CU selects one or more quasi-target cells for the UE based on the L3 measurement report of the UE and allocates resources to the UE. For quasi-target cells across CUs, the resources provided by the source CU come from the public resource pool provided by the target CU in step S802. It should be noted that the source CU can arbitrarily combine the resources within the unified cell provided by the target CU. For example, select a C-RNTI from the C-RNTI pool, select a CG configuration from the CG pool, select a CORESET from the CORESET pool, select a preamble from the preamble pool, select a PRACH from the PRACH opportunity pool, etc.

[0207] The types of uplink resources provided by the source cell to the UE can vary. For example, some cells may provide resources including CG for the UE to transmit uplink data. For example, some cells may provide CORESET for the UE to obtain DG by receiving PDCCH and thus transmit uplink data.

[0208] In step S808, the UE obtains the TA of each quasi-target cell.

[0209] In step S810 , the UE sends an L1 measurement report to a source DU (or source cell).

[0210] In step S812, the source DU (or source cell) sends an L1 / L2 handover command to the UE.

[0211] In step S814, the UE accesses the target cell. Step S814 includes S814a and S814b. In step S814a, the UE sends uplink data to the target DU. In step S814b, the target DU sends a handover confirmation to the UE.

[0212] In step S816, after receiving the uplink data sent by the UE, the target DU may indicate to the target CU that the UE has accessed.

[0213] In step S818, the target CU indicates to the source CU that the UE has successfully accessed. The target CU may send an indication message to the source CU, indicating that the UE has successfully accessed. The indication message may include the UE identifier. The UE identifier may be the C-RNTI corresponding to the UE. For example, the target CU may notify the source CU that "UE with C-RNTI XXX has successfully accessed." The C-RNTI corresponding to the UE may be allocated to the UE by the target cell or by the source cell.

[0214] In step S820, after receiving the indication that the UE has successfully accessed, the source CU may send the UE's new key key* to the target CU.

[0215] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 8 . The device embodiment of the present application is described in detail below in conjunction with Figures 9 and 10 . It should be understood that the description of the method embodiment corresponds to the description of the device embodiment. Therefore, for parts not described in detail, reference can be made to the above method embodiment.

[0216] FIG9 is a schematic block diagram of a terminal device provided in an embodiment of the present application. The terminal device 900 shown in FIG9 can be any of the first terminal devices described above. The terminal device 900 shown in FIG9 can include a receiving unit 910.

[0217] The receiving unit 910 is used to receive first information sent by the first CU, where the first information is used to indicate target resources, and the target resources are used for the first terminal device to switch from a first cell to a second cell. The first cell is a cell within the first CU, and the second cell is a cell within the second CU.

[0218] In some possible implementations, the target resource is selected by the first CU from a resource pool, or the target resource is configured by the second CU to the first CU.

[0219] In some possible implementations, the target resource is selected by the first CU from a resource pool, where the resource pool includes resources reserved by the second cell for terminal devices within the first CU.

[0220] In some possible implementations, after the first terminal device switches from the first cell to the second cell, the first resource in the target resources satisfies any one of the following: the first resource is released, and the first resource is used for other terminal devices in the first CU to switch to the second cell; the first resource cannot be used for other terminal devices in the first CU to switch to the second cell; the first resource is used for communication between the first terminal device and the second cell.

[0221] In some possible implementations, if the target resource is a dedicated resource of the first terminal device, the first resource in the target resource cannot be used for other terminal devices in the first CU to switch to the second cell.

[0222] In some possible implementations, if the target resource is not a dedicated resource for the first terminal device, the first resource in the target resource is released, and the first resource is used for other terminal devices within the first CU to switch to the second cell; or the first resource is used for communication between the first terminal device and the second cell.

[0223] In some possible implementations, the receiving unit is further used to: receive a first message sent by the first CU to determine whether the target resource is a dedicated resource of the first terminal device.

[0224] In some possible implementations, the type of the second cell is used to determine whether the target resource is a dedicated resource for the first terminal device.

[0225] In some possible implementations, the first message indicates whether the target resource is a dedicated resource of the first terminal device through an implicit indication.

[0226] In some possible implementations, whether the target resource is a dedicated resource of the first terminal device is determined based on a resource type included in the target resource.

[0227] In some possible implementations, whether the target resource is a dedicated resource of the first terminal device is determined based on whether the target resource includes a key.

[0228] In some possible implementations, the receiving unit is further used to: receive second indication information sent by the first CU, where the second indication information is used to indicate whether the first resource can be used for communication between the first terminal device and the second cell.

[0229] In some possible implementations, the second indication information is carried in the first information, or the first indication information is carried in a handover command.

[0230] In some possible implementations, if the first resource cannot be used for other terminal devices in the first CU to switch to the second cell, the first resource is updated by the second cell.

[0231] In some possible implementations, the first resource includes one or more of the following: C-RNTI, CG, CORESET, preamble, PRACH opportunity, key, and key-related parameters.

[0232] In some possible implementations, the resource pool includes resources reserved by multiple cells in the second CU for terminal devices in the first CU.

[0233] In some possible implementations, the multiple cells reserve the same type of resources for the terminal devices in the first CU, or the multiple cells reserve different types of resources for the terminal devices in the first CU.

[0234] In some possible implementations, the target resource includes a second resource, the second resource belongs to a first type of resource, the second resource is a resource selected by the first CU from a first resource set, and the first resource set is the first type of resource reserved by the second cell for the terminal device within the first CU.

[0235] In some possible implementations, the target resource is configured by the second CU to the first CU.

[0236] In some possible implementations, when the first CU receives third indication information sent by the second CU, the resources reserved for the first terminal device in the third cell in the first CU are released by the first CU, wherein the third indication information is used to instruct the first terminal device to switch to the second cell.

[0237] In some possible implementations, when the third CU receives the fourth indication information sent by the first CU, the resources reserved for the first terminal device by the fourth cell in the third CU are released by the third CU, wherein the fourth indication information is used to instruct the first terminal device to switch to the second cell.

[0238] In some possible implementations, after the first terminal device switches to the second cell, the receiving unit is further configured to:

[0239] Receive first key-related parameters sent by the first CU, where the first key-related parameters are used for communication between the first terminal device and the second cell.

[0240] In some possible implementations, the target resource includes one or more of the following resources: C-RNTI, CG,

[0241] CORESET, preamble, PRACH timing, key, key-related parameters.

[0242] In some possible implementations, the switching method of the first terminal device from the first cell to the second cell is layer 1 / layer 2 based switching.

[0243] In an optional embodiment, the receiving unit 910 may be a transceiver 1030, and the determining unit and the releasing unit may be a processor 1010. The terminal device 900 may further include a memory 1020, as specifically shown in FIG10 .

[0244] Figure 10 is a schematic block diagram of a communication device according to an embodiment of the present application. The dashed lines in Figure 10 indicate that the unit or module is optional. The device 1000 may be used to implement the method described in the above method embodiment. The device 1000 may be a chip, a terminal device, or a network device.

[0245] The device 1000 may include one or more processors 1010. The processor 1010 may support the device 1000 to implement the method described in the method embodiment above. The processor 1010 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0246] The apparatus 1000 may further include one or more memories 1020. The memories 1020 store programs that can be executed by the processor 1010, causing the processor 1010 to perform the methods described in the above method embodiments. The memories 1020 may be independent of the processor 1010 or integrated into the processor 1010.

[0247] The apparatus 1000 may further include a transceiver 1030. The processor 1010 may communicate with other devices or chips via the transceiver 1030. For example, the processor 1010 may transmit and receive data with other devices or chips via the transceiver 1030.

[0248] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal or network device provided in the present application, and the program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0249] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal or network device provided in the present application, and the program causes a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0250] The embodiments of the present application also provide a computer program. The computer program can be applied to the terminal or network device provided in the embodiments of the present application, and the computer program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0251] It should be understood that the terms "system" and "network" in this application can be used interchangeably. In addition, the terms used in this application are only used to explain the specific embodiments of this application and are not intended to limit this application. The terms "first", "second", "third", and "fourth" in the specification and claims of this application and the accompanying drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0252] In the embodiments of this application, the term "indication" may refer to a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" may refer to a direct indication of B, e.g., B can obtain information through A; it may refer to an indirect indication of B, e.g., A indicates C, e.g., B can obtain information through C; or it may refer to an association between A and B.

[0253] In the embodiment of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0254] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and indication, configuration and configuration, etc.

[0255] In the embodiments of the present application, "pre-definition" or "pre-configuration" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device and a network device). The present application does not limit the specific implementation method. For example, pre-definition may refer to information defined in a protocol.

[0256] In the embodiments of the present application, the “protocol” may refer to a standard protocol in the communications field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0257] In the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0258] In various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0259] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0260] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0261] 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.

[0262] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0263] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A wireless communication method, characterized in that, Including: The first terminal device receives first information sent by a first central unit (CU), where the first information is used to indicate a target resource for the first terminal device to switch from a first cell to a second cell. The first cell is a cell within the first CU, and the second cell is a cell within a second CU.

2. The method according to claim 1, characterized in that The target resource is selected by the first CU from a resource pool, or the target resource is configured by the second CU for the first CU.

3. The method according to claim 2, wherein The target resource is selected by the first CU from a resource pool, and the resource pool includes resources reserved for the terminal devices within the first CU by the second cell.

4. The method according to claim 3, wherein After the first terminal device switches from the first cell to the second cell, the first resource among the target resources satisfies any one of the following: The first resource is released and is used for other terminal devices within the first CU to switch to the second cell; The first resource cannot be used for other terminal devices within the first CU to switch to the second cell; The first resource is used for communication between the first terminal device and the second cell.

5. The method according to claim 4, wherein If the target resource is a dedicated resource of the first terminal device, the first resource among the target resources cannot be used for other terminal devices within the first CU to switch to the second cell.

6. The method according to claim 4, wherein If the target resource is not a dedicated resource of the first terminal device, the first resource among the target resources is released and is used for other terminal devices within the first CU to switch to the second cell; or The first resource is used for communication between the first terminal device and the second cell.

7. The method according to claim 5 or 6, characterized in that, The method further includes: The first terminal device receives a first message sent by the first CU to determine whether the target resource is a dedicated resource of the first terminal device.

8. The method according to any one of claims 1-7, characterized in that, The type of the second cell is used to determine whether the target resource is a dedicated resource of the first terminal device.

9. The method according to claim 7, wherein The first message indicates whether the target resource is a dedicated resource of the first terminal device in an implicit indication manner.

10. The method according to claim 5 or 6, characterized in that, Whether the target resource is a dedicated resource of the first terminal device is determined based on the resource type included in the target resource.

11. The method according to claim 10, wherein Whether the target resource is a dedicated resource of the first terminal device is determined based on whether the target resource includes a key.

12. The method according to any one of claims 4 to 11, characterized in that, The method further includes: The first terminal device receives second indication information sent by the first CU, where the second indication information is used to indicate whether the first resource can be used for communication between the first terminal device and the second cell.

13. The method according to claim 12, characterized in that, The second indication information is carried in the first information, or the first indication information is carried in a handover command.

14. The method according to any one of claims 4 or 5, characterized in that If the first resource cannot be used for other terminal devices within the first CU to switch to the second cell, the first resource is updated by the second cell.

15. The method according to any one of claims 4-14, characterized in that, The first resource includes one or more of the following: cell radio network temporary identifier (C-RNTI), configured grant (CG), control resource set (CORESET), preamble, physical random access channel (PRACH) occasion, key, key-related parameter.

16. The method according to any one of claims 3-15, characterized in that, The resource pool includes resources reserved by multiple cells in the second CU for the terminal devices in the first CU.

17. The method according to claim 16, characterized in that, The resource types reserved by the multiple cells for the terminal devices in the first CU are the same, or the resource types reserved by the multiple cells for the terminal devices in the first CU are different.

18. The method according to claim 16 or 17, characterized in that, The target resource includes a second resource, which belongs to the first type of resource. The second resource is a resource selected by the first CU from a first resource set, and the first resource set is the first type of resource reserved by the second cell for the terminal devices in the first CU.

19. The method according to claim 2, characterized in that, The target resource is configured by the second CU for the first CU.

20. The method according to claim 19, wherein When the first CU receives the third indication information sent by the second CU, the resources reserved by the third cell in the first CU for the first terminal device are released by the first CU, where the third indication information is used to indicate that the first terminal device switches to the second cell.

21. The method according to claim 19, wherein When the third CU receives the fourth indication information sent by the first CU, the resources reserved by the fourth cell in the third CU for the first terminal device are released by the third CU, where the fourth indication information is used to indicate that the first terminal device switches to the second cell.

22. The method according to any one of claims 1-21, characterized in that, After the first terminal device switches to the second cell, the method further includes: The first terminal device receives the first key-related parameter sent by the first CU, and the first key-related parameter is used for communication between the first terminal device and the second cell.

23. The method according to any one of claims 1-22, characterized in that, The target resource includes one or more of the following resources: C-RNTI, CG, CORESET, preamble, PRACH occasion, key, key-related parameter.

24. The method according to any one of claims 1-23, characterized in that, The handover mode of the first terminal device from the first cell to the second cell is a layer 1 / layer 2 based handover.

25. A terminal device, characterized in that, The terminal device is a first terminal device, including: A receiving unit, configured to receive first information sent by a first centralized unit (CU), where the first information is used to indicate a target resource, and the target resource is used for the first terminal device to switch from a first cell to a second cell. The first cell is a cell in the first CU, and the second cell is a cell in the second CU.

26. The terminal device according to claim 25, wherein The target resource is selected by the first CU from a resource pool, or the target resource is configured by the second CU for the first CU.

27. The terminal device according to claim 26, characterized in that, The target resource is selected by the first CU from a resource pool, and the resource pool includes resources reserved by the second cell for the terminal devices in the first CU.

28. The terminal device according to claim 27, wherein After the first terminal device switches from the first cell to the second cell, the first resource in the target resource satisfies any one of the following: The first resource is released, and the first resource is used for other terminal devices in the first CU to switch to the second cell; The first resource cannot be used for other terminal devices in the first CU to switch to the second cell; The first resource is used for communication between the first terminal device and the second cell.

29. The terminal device according to claim 28, characterized in that, If the target resource is a dedicated resource of the first terminal device, the first resource in the target resource cannot be used for other terminal devices in the first CU to switch to the second cell.

30. The terminal device according to claim 28, wherein, If the target resource is not a dedicated resource of the first terminal device, the first resource in the target resource is released, and the first resource is used for other terminal devices in the first CU to switch to the second cell; or The first resource is used for communication between the first terminal device and the second cell.

31. The terminal device according to claim 29 or 30, characterized in that, The receiving unit is further configured to: Receive a first message sent by the first CU to determine whether the target resource is a dedicated resource of the first terminal device.

32. The terminal device according to any one of claims 25-31, characterized in that, The type of the second cell is used to determine whether the target resource is a dedicated resource of the first terminal device.

33. The terminal device according to claim 31, characterized in that, The first message indicates whether the target resource is a dedicated resource of the first terminal device by an implicit indication method.

34. The terminal device according to claim 29 or 30, characterized in that, Whether the target resource is a dedicated resource of the first terminal device is determined based on the resource type included in the target resource.

35. The terminal device according to claim 34, characterized in that, Whether the target resource is a dedicated resource of the first terminal device is determined based on whether the target resource includes a key.

36. The terminal device according to any one of claims 28-35, characterized in that, The receiving unit is further configured to: Receive second indication information sent by the first CU, where the second indication information is used to indicate whether the first resource can be used for communication between the first terminal device and the second cell.

37. The terminal device according to claim 36, wherein The second indication information is carried in the first information, or the first indication information is carried in a handover command.

38. The terminal device according to any one of claims 28 or 29, characterized in that If the first resource cannot be used for other terminal devices in the first CU to switch to the second cell, the first resource is updated by the second cell.

39. The terminal device according to any one of claims 28-38, characterized in that, The first resource includes one or more of the following: Cell Radio Network Temporary Identifier C-RNTI, Configuration Grant CG, Control Resource Set CORESET, Preamble, Physical Random Access Channel PRACH occasion, Key, Key-related parameter.

40. The terminal device according to any one of claims 27-39, characterized in that, The resource pool includes resources reserved for terminal devices in the first CU by multiple cells in the second CU.

41. The terminal device according to claim 40, characterized in that, The resource types reserved for terminal devices in the first CU by the multiple cells are the same, or the resource types reserved for terminal devices in the first CU by the multiple cells are different.

42. The terminal device according to claim 40 or 41, characterized in that, The target resource includes a second resource, the second resource belongs to a first type of resource, the second resource is a resource selected by the first CU from a first resource set, and the first resource set is the first type of resource reserved for terminal devices in the first CU by the second cell.

43. The terminal device according to claim 26, wherein The target resource is configured by the second CU to the first CU.

44. The terminal device according to claim 43, wherein, In the case where the first CU receives third indication information sent by the second CU, the resources reserved for the first terminal device by a third cell in the first CU are released by the first CU, where the third indication information is used to indicate that the first terminal device switches to the second cell.

45. The terminal device according to claim 43, wherein In the case that the third CU receives the fourth indication information sent by the first CU, the resources reserved for the first terminal device by the fourth cell in the third CU are released by the third CU, where the fourth indication information is used to indicate that the first terminal device switches to the second cell.

46. The terminal device according to any one of claims 25-45, characterized in that, After the first terminal device switches to the second cell, the receiving unit is further configured to: Receive first key-related parameters sent by the first CU, where the first key-related parameters are used for communication between the first terminal device and the second cell.

47. The terminal device according to any one of claims 25-46, characterized in that, The target resources include one or more of the following resources: C-RNTI, CG, CORESET, preamble, PRACH occasion, key, key-related parameter.

48. The terminal device according to any one of claims 25-47, characterized in that, The handover mode for the first terminal device to hand over from the first cell to the second cell is a layer 1 / layer 2-based handover.

49. A terminal device, characterized in that, The terminal device is a first terminal device, including a transceiver, a memory, and a processor. The memory is used to store programs, and the processor is used to call the programs in the memory and control the transceiver to receive or send signals, so that the terminal executes the method according to any one of claims 1-24.

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