CN118176774A

CN118176774A - Wireless communication method and device

Info

Publication number: CN118176774A
Application number: CN202480000237.1A
Authority: CN
Inventors: 黄曲芳
Original assignee: Quectel Wireless Solutions Co Ltd
Current assignee: Quectel Wireless Solutions Co Ltd
Priority date: 2024-01-19
Filing date: 2024-01-19
Publication date: 2024-06-11

Abstract

A wireless communication method and apparatus are provided. The method comprises the following steps: the method comprises the steps that a first terminal device receives first information sent by a first CU, wherein the first information is used for indicating target resources, the target resources are used for switching the first terminal device from a first cell to a second cell, and the second cell is a cell in the second CU.

Description

Wireless communication method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a wireless communication method and apparatus.

Background

The cell switch of the terminal device may be a cell switch in the same Central Unit (CU), or may be a cell switch across CUs. How the terminal device implements cell switching across CUs, there is no clear solution at present.

Disclosure of Invention

The application provides a wireless communication method and a wireless communication device. Various aspects of the application are described below.

In a first aspect, a wireless communication method is provided, including: the method comprises the steps that a first terminal device receives first information sent by a first CU, the first information is used for indicating target resources, the target resources are used for switching the first terminal device 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.

In a second aspect, there is provided a terminal device, the terminal device being a first terminal device, comprising: the receiving unit is configured to receive first information sent by a first CU, where the first information is used to indicate a target resource, where the target resource is used for the first terminal device to switch from a first cell to a second cell, where the first cell is a cell in the first CU, and the second cell is a cell in the second CU.

In a third aspect, there is provided a terminal device, the terminal device being a first terminal device, comprising a processor, a memory and a communication interface, the memory being for storing one or more computer programs, the processor being for invoking the computer programs in the memory to cause the terminal device to perform part or all of the steps in the method of the first aspect.

In a fourth aspect, an embodiment of the present application provides a communication system, where the system includes the terminal device and/or the network device. In another possible design, the system may further include other devices that interact with the terminal device or the network device in the solution provided by the embodiment of the present application.

In a fifth aspect, embodiments of the present application provide a computer-readable storage medium storing a computer program that causes a communication device (e.g., a terminal device or a network device) to perform some or all of the steps of the methods of the above aspects.

In a sixth aspect, embodiments of the present application provide a computer program product, wherein the computer program product comprises a non-transitory computer readable storage medium storing a computer program 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 of the above aspects. In some implementations, the computer program product can be a software installation package.

In a seventh aspect, embodiments of the present application provide a chip comprising a memory and a processor, the processor being operable to invoke and run a computer program from the memory to implement some or all of the steps described in the methods of the above aspects.

The application indicates the cell resource (i.e. the resource of the second cell) in the target CU (i.e. the second CU) to the first terminal equipment through the source CU (i.e. the first CU in the previous process), so that the terminal equipment can be switched to the second cell according to the resource of the second cell, thereby realizing the cell switching across CUs and providing an explicit scheme for the cell switching of the terminal equipment across CUs.

Drawings

Fig. 1 is a wireless communication system 100 to which embodiments of the present application are applied.

Fig. 2 is a schematic flow chart of an L3 based cell handover.

Fig. 3 is a schematic flow chart of an L1/L2 based cell handover.

Fig. 4 is a schematic diagram of a switching scenario provided in an embodiment of the present application.

Fig. 5 is a schematic flow chart of a wireless communication method according to an embodiment of the present application.

Fig. 6 is a schematic flow chart of a cell handover across CUs provided by an embodiment of the present application.

Fig. 7 is a schematic flow chart of another cell handover across CUs provided by an embodiment of the present application.

Fig. 8 is a schematic flow chart of another cell handover across CUs provided by an embodiment of the present application.

Fig. 9 is a schematic block diagram of a terminal device provided in an embodiment of the present application.

Fig. 10 is a schematic structural diagram of a communication device according to an embodiment of the present application.

Detailed Description

The technical scheme of the application will be described below with reference to the accompanying drawings.

Fig. 1 is a wireless communication system 100 to which embodiments of the present application are applied. The wireless communication system 100 may include a network device 110 and a terminal device 120. Network device 110 may be a device that communicates with terminal device 120. Network device 110 may provide communication coverage for a particular geographic area and may communicate with terminal devices 120 located within the coverage area.

Fig. 1 illustrates one network device and two terminals by way of example, and the wireless communication system 100 may alternatively include multiple network devices and may include other numbers of terminal devices within the coverage area of each network device, as embodiments of the application are not limited in this regard.

Optionally, the wireless communication system 100 may further include a network controller, a mobility management entity, and other network entities, which are not limited by the embodiment of the present application.

It should be understood that the technical solution of the embodiment of the present application may be applied to various communication systems, for example: fifth generation (5th generation,5G) systems or New Radio (NR), long term evolution (long term evolution, LTE) systems, LTE frequency division duplex (frequency division duplex, FDD) systems, LTE time division duplex (time division duplex, TDD), and the like. The technical scheme provided by the application can also be applied to future communication systems, such as a sixth generation mobile communication system, a satellite communication system and the like.

The terminal device in the embodiments of the present application may also be referred to as a User Equipment (UE), an access terminal, a subscriber unit, a subscriber station, a Mobile Station (MS), a Mobile Terminal (MT), a remote station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The terminal device in the embodiment of the application can be a device for providing voice and/or data connectivity for a user, and can be used for connecting people, things and machines, such as a handheld device with a wireless connection function, a vehicle-mounted device and the like. The terminal device in the embodiments of the present application may be a mobile phone (mobile phone), a tablet (Pad), a notebook, a palm, a Mobile Internet Device (MID), a wearable device, a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in unmanned (SELF DRIVING), a wireless terminal in teleoperation (remote medical surgery), a wireless terminal in smart grid (SMART GRID), a wireless terminal in transportation security (transportation safety), a wireless terminal in smart city (SMART CITY), a wireless terminal in smart home (smart home), and the like. Alternatively, the UE may be used to act as a base station. For example, the UEs may act as scheduling entities that provide side-uplink signals between UEs in V2X or D2D, etc. For example, a cellular telephone and a car communicate with each other using side-link signals. Communication between the cellular telephone and the smart home device is accomplished without relaying communication signals through the base station.

The network device in the embodiment of the present application may be a device for communicating with a terminal device, and the network device 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 (radio access network, RAN) node (or device) that accesses the terminal device to the wireless network. The base station may broadly cover or replace various names in the following, such as: a node B (NodeB), an evolved NodeB (eNB), a next generation NodeB (gNB), a relay station, an access point, a transmission point (TRANSMITTING AND RECEIVING point, TRP), a transmission point (TRANSMITTING POINT, TP), a master MeNB, a secondary SeNB, a multi-mode wireless (MSR) node, a home base station, a network controller, an access node, a radio node, an Access Point (AP), a transmission node, a transceiver node, a baseband unit (BBU), a remote radio unit (Remote Radio Unit, RRU), an active antenna unit (ACTIVE ANTENNA unit, AAU), a radio head (remote radio head, RRH), a CU, a Distributed Unit (DU), a positioning node, and the like. The base station may 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 may also refer to a communication module, modem, or chip for placement within the aforementioned device or apparatus. The base station may also be a mobile switching center, a device-to-device D2D, a vehicle-to-everything (V2X), a device that performs a base station function in machine-to-machine (M2M) communication, a network-side device in a 6G network, a device that performs a base station function in a future communication system, or the like. The base stations may support networks of the same or different access technologies. The embodiment of the application does not limit the specific technology and the specific equipment form adopted by the network equipment.

The base station may be fixed or mobile. For example, a helicopter or drone may be configured to act as a mobile base station, and one or more cells may move according to the location of the mobile base station. In other examples, a helicopter or drone may be configured to function as a device to communicate with another base station.

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

Network devices and terminal devices may be deployed on land, including indoors or outdoors, hand-held or vehicle-mounted; the device can be deployed on the water surface; but also on aerial planes, balloons and satellites. In the embodiment of the application, the scene where the network equipment and the terminal equipment are located is not limited.

It should be understood that all or part of the functionality of the communication device in the present application may also be implemented by software functions running on hardware or by virtualized functions instantiated on a platform, such as a cloud platform.

Cell Handover (HO) is intended to improve the continuity of the service provided by the communication system to the terminal equipment. In a wireless communication system, when a terminal device moves from one cell (also called a "source cell") to another cell, the terminal device needs to be handed over to the other cell (also called a "target cell") in order to maintain communication. Wherein the cell may be a primary cell (PRIMARY CELL, PCell) or a primary secondary cell (primary secondary cell, PSCell).

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

For a conventional handover mechanism, in order to improve the continuity of the service provided by the communication system for the terminal device in a connected state, the network device sends a handover command to the terminal device at an appropriate time (for example, the signal measurement result of the terminal device in the serving cell is lower than a threshold value) to instruct the terminal device to perform cell handover. In some implementations, the handover command may be a radio resource control (radio resource control, RRC) reconfiguration message that includes synchronization reconfiguration information.

For the conditional handover (conditional handover, CHO) mechanism, the network device may configure the configuration of one or more candidate cells, and the conditional handover event associated with the one or more candidate cells, to the terminal device. The conditional switch event may also be referred to as a conditional switch trigger condition. Accordingly, the terminal device may determine whether the conditional handover event is satisfied based on the signal measurement result of the candidate cell. If the terminal device determines that a certain candidate cell meets the conditional handover event, the terminal device may initiate random access to the candidate cell.

Fig. 2 is a schematic flow chart of a cell handover based on L3 according to an embodiment of the present application.

Referring to fig. 2, in step S210, the terminal device transmits an L3 measurement report to a source cell.

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.

In step S230, the source cell transmits a handover request to the target cell.

In step S240, the target cell transmits a handover request response to the source cell.

In step S250, the source cell transmits an L3 handover command to the terminal device.

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

For L3 handover, the source cell does not make any preparation before determining the handover, and after determining the handover, starts to communicate with the target cell again to prepare for the handover. The source cell may then inform the terminal device to enable the terminal device to access the target cell. The L3 based cell handover is triggered by the L3 measurement and is done through RRC signaling. L3-based handover requires reconfiguration of the RRC layer or packet data convergence protocol (PACKET DATA convergence protocol, PDCP) layer and resetting of the medium access control (medium access control, MAC) layer and/or physical layer, which increases the complexity of the handover procedure and increases handover delay. Thus, LTM mechanisms are introduced. The LTM realizes the change of the service cell of the terminal equipment under the condition of maintaining the high-layer configuration unchanged through the L1/L2 signaling, thereby being beneficial to reducing delay, overhead and interrupt time.

The following describes a cell handover procedure based on L1/L2 with reference to fig. 3.

In step S310, the target cell transmits first configuration information to the source cell. The first configuration information is used for configuring resources of the target cell. The resources of the target cell are used for the terminal device to switch to the target cell. The first configuration information may also be referred to as configuration information of the target cell.

The resources of the target cell may include one or more of the following: cell radio network temporary identity (cell-radio network temporary identifier, C-RNTI), configuration grant (configured grant, CG), control-resource set (CORESET), preamble (preamble), physical Random Access Channel (PRACH) occasion, and the like.

In step S320, the source cell transmits second configuration information to the terminal device. The second configuration information includes the first configuration information.

In step S330, the terminal device acquires timing advance (TIMING ADVANCE, TA) of the target cell based on the second configuration information.

In step S340, the terminal device transmits an L1 measurement report to the source cell.

In step S350, the source cell transmits an L1 handover command to the terminal device.

In step S360, the terminal device transmits uplink data to the target cell using the CG.

In step S370, the target cell transmits uplink resource allocation to the terminal device.

In step S380, the terminal device searches for downlink control information (downlink control information, DCI) according to the configuration of the search space, obtains dynamic grants (DYNAMIC GRANT, DG), and sends uplink data to the target cell using DG.

In step S390, the target cell transmits a handover response to the terminal device.

As can be seen from fig. 3, for L1/L2 handover, the source cell communicates with one or more target cells before handover occurs, the target cells allocate resources for the terminal device for handover, and the terminal device is informed of these configurations. The terminal equipment can acquire the TA values of one or more target cells, and when the switching condition is met, the source cell notifies the terminal equipment to switch to a target cell meeting the condition through the L1 switching command.

There are two ways for the terminal device to access the target cell, and the two ways are respectively described below. In one manner, if the target cell allocates CG resources to the terminal device, the terminal device may send uplink data to the target cell through the CG resources, as described in step S360. In the second mode, if the target cell does not allocate CG resources to the terminal device, the terminal device may monitor a physical downlink control channel (physical downlink control channel, PDCCH) of the target cell, and obtain uplink resources dynamically allocated to the terminal device. The terminal device may transmit uplink data to the target cell through the dynamic uplink resource as described in step S370 and step S380.

After receiving the uplink data sent by the terminal equipment, the target cell can send a switching response to the terminal equipment, and the L1/L2 switching flow is ended.

Compared with the L3 switching flow, the L1/L2 switching flow places a large amount of preparation work before the switching time point, waits until the wireless condition triggering the switching is satisfied, and after receiving the L1 switching command sent by the source cell, the terminal equipment can send uplink data to the target cell by utilizing the TA and the uplink resource obtained before. Therefore, the time from "satisfying the switching condition" to "switching completion" becomes short, thereby reducing the switching delay.

Fig. 3 shows 3 different switching scenarios. In the diagram (a) in fig. 3, the source cell and the target cell both belong to the same DU, and the source cell and the target cell both belong to the same CU, and this switching manner is called cell switching in the same CU. In fig. 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, and this switching is called cell switching in the same CU. In fig. 3 (c), the source cell and the target cell belong to different DUs, and the source cell and the target cell belong to different CUs, which is called a cell handover across CUs.

At present, the flow of cell switching is only applicable to cell switching under the same CU, namely, the source cell and the target cell are controlled by the same CU. That is, the present switching flow is applicable only to the scenes shown in the diagrams (a) and (b) in fig. 3. For the scenario shown in fig. 3 (a) and (b), taking L1/L2 handover as an example, C-RNTI allocation, CG allocation, and the like involved in the handover are all performed by the control function in the CU, and if cell handover occurs inside the CU, the actions of C-RNTI allocation, CG allocation, and the like all occur inside the same CU, and the CU may allocate resources for the terminal device in multiple quasi-target cells. As long as the terminal device accesses one target cell, the CU may immediately delete the resources allocated to the terminal device in the other quasi-target cell. However, there is no explicit scheme for the handover across CUs as described in the graph (c) of fig. 3.

Based on this, the embodiment of the present application provides a wireless communication method, which indicates, to a first terminal device, a cell resource (i.e., a resource of a second cell) in a target CU (i.e., a second CU) through a source CU (i.e., a first CU), so that the terminal device can switch to the second cell according to the resource of the second cell, thereby implementing cell switching across CUs, and providing an explicit scheme for cell switching of the terminal device across CUs.

The following describes in detail a wireless communication method provided in an embodiment of the present application with reference to fig. 5.

Referring to fig. 5, in step S510, a first terminal device receives first information transmitted by a first CU. There may be a plurality of terminal devices in the first CU, and the first terminal device is one of the plurality of terminal devices. The terminal device within the first CU may refer to a terminal device that accesses the first CU or a terminal device that communicates with the first CU.

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 the source cell, or a CU of the serving cell.

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.

In some embodiments, the target resources may include resources for cell handover. For example, the target resources may include resources available for random access. In some embodiments, the target resource may comprise a resource with which the terminal device communicates with the second cell. The terminal device may access the second cell and/or communicate with the second cell via the target resource.

The embodiment of the application does not limit the type of the target resource in detail. In some embodiments, the target resource may include one or more of the following: C-RNTI, CG, CORESET, preamble, PRACH occasion, key (key), key related parameters, etc. In some embodiments, since CG and CORESET are both available for the first terminal device to transmit uplink data, the target resource may include one of CG and CORESET. That is, the target resource may include one or more of the following: C-RNTI, CG, preamble, PRACH opportunity, key; or the target resource may include one or more of the following: C-RNTI, CORESET, preamble, PRACH occasion, key. The preamble and the PRACH opportunity can be used for random access of the first terminal equipment. C-RNTI, CG, CORESET and keys may be used for the first terminal device to communicate with the second cell.

The C-RNTI may be used to identify the first terminal device, through which the network device may be enabled to uniquely identify the first terminal device.

CG resources may be used for the first terminal device to transmit uplink data.

CORESET may be configured to receive the PDCCH or DCI sent by the second cell and obtain the DG through the PDCCH or DCI, so as to transmit the uplink data through the DG.

The preamble and PRACH occasion 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.

The key may be used to encrypt communication data between the first terminal device and the second cell to ensure security of the communication. The key may be, for example, a key for integrity verification. The key-related parameters may be used to generate a key. In some embodiments, the key may be generated by the first CU, which may send the key to the first terminal device and the second CU, such that the first terminal device and the second CU may communicate based on the key. In some embodiments, the key may also be generated by the first terminal device. The first CU may send parameters for generating the key to the first terminal device, which may generate the key based on the parameters and agreed algorithm. The first CU may 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.

The embodiment of the application does not limit the carrying mode of the first information in detail. 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 is carried in a handover configuration message and a handover command, and the first CU may indicate a part of the resources in the target resource to the first terminal device through the handover configuration message and indicate another part of the resources in the target resource to the first terminal device through the handover command.

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 a terminal device switching from a first cell to a second cell may also be referred to as a cross-CU handover. Of course, in some embodiments, the second cell may also be a cell in the first CU, which is not specifically limited in the embodiments of the present application.

The mode of cell switching performed by the first terminal device in the embodiment of the application is not particularly limited. In some implementations, the first terminal device may perform the L3 handover. That is, the first terminal device may be handed over to the second cell by means of L3 handover. In some implementations, the first terminal device may perform an L1/L2 handover. That is, the first terminal device may switch to the second cell through the L1/L2 handover. The switching delay of the first terminal equipment can be reduced through L1/L2 switching.

The target resource may be obtained by the first CU, and the method for obtaining the target resource by the first CU in the embodiment of the present application is not specifically limited. As one 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 pool of resources. The resource pool may comprise resources reserved by the second cell for terminal devices within the first CU. These two modes are described separately below.

The manner in which the target resource is configured by the second CU to the first CU is described first.

In some implementations, the second CU may send first configuration information to the first CU, which 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.

In some implementations, the first CU may send a request message to the second CU, which may be used to request the 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 for handover preparation by the second CU.

In some implementations, the first CU may send a request message to the second CU if the first terminal device satisfies the trigger condition. The trigger condition may be a condition that triggers LTM flow.

In some implementations, whether the first terminal device satisfies the trigger condition may be determined based on the measurement report. The measurement report may be sent by the first terminal device to the first CU. The measurement report may be an L3 measurement report. The first CU may determine whether to initiate an LTM procedure based on the measurement report.

In some implementations, the first information may be used to indicate resources of one or more cells. The one or more cells may also be referred to as quasi-target cells. Taking the first information as an example for indicating the resources of the plurality of cells, the resources of the plurality of cells may be used for the first terminal device to switch to the plurality of cells, respectively. For example, the plurality of cells includes a second cell and a third cell, resources of the second cell are available for the first terminal device to switch to the second cell, and resources of the third cell are available for the first terminal device to switch to the third cell.

The embodiment of the application does not specifically limit a plurality of cells. In some implementations, the CUs corresponding to the plurality of cells may be the same or different. In some implementations, the plurality of cells may include cells within one CU, or may include cells within a plurality of CUs. For example, the plurality of cells may include cells within the second CU. For another example, the plurality of cells may include a cell within the first CU and a cell within the second CU. For another example, the plurality of cells may include a cell within the first CU, a cell within the second CU, and a cell within the third CU.

In some implementations, if the first terminal device switches to the second cell of the multiple cells, resources of other cells of the multiple cells may be released, and the released resources may be used by other terminal devices, so that the utilization rate of the resources may be improved. For example, the plurality of cells includes a second cell, a third cell, and a fourth cell, and after the first terminal device switches to the second cell, resources of the third cell and the fourth cell may be released.

In some implementations, if the third cell is a cell within the first CU, the first CU may release the resources of the third cell, or alternatively, the resources of the third cell may be released by the first CU.

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 indicate the first terminal device to switch to the second cell. For example, the second CU may send third indication information to the first CU after the first terminal device successfully switches to the second cell, so as to indicate that the first terminal device successfully switches to the second cell. After receiving the third indication information, the first CU may release the resources of the third cell.

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

In some embodiments, if the fourth cell is a cell within the third CU, the third CU may release the resources of the fourth cell, or alternatively, the resources of the fourth cell may be released by the third CU.

In some implementations, the third CU may release the resources of the fourth cell if the fourth indication information is received. The fourth indication information may be used to instruct the first terminal device to handover 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 to switch the first terminal device to the second cell, the first CU may send fourth instruction information to the third CU.

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

In some implementations, the second CU may send third indication information to the first CU in case it is determined that the cell switch by the first terminal device is a cell switch across CUs. In some embodiments, the second CU may determine, based on the C-RNTI of the first terminal device, whether the cell handover by the first terminal device is a cell handover across CUs. In some embodiments, the second CU may determine whether the cell switch by the first terminal device is a cell switch across CUs based on the location of the resources used by the first terminal device to access the second cell. The resource locations may include CG resource locations.

The manner in which the first CU obtains the target resource from the resource pool is described below.

In some implementations, the resource pool is a common resource pool, that is, the resources in the resource pool are common resources. The resources in the resource pool do not belong to any terminal equipment, and any terminal equipment can use the resources in the resource pool to perform cell switching. By selecting resources from the resource pool to perform cell switching, the interactive load between CUs can be greatly reduced, and the switching flow is simplified.

In some implementations, resources of one or more cells may be included in the resource pool. The one or more cells may also be referred to as quasi-target cells. Taking the example that the resource pool includes resources of a plurality of cells, the resources of the plurality of cells can be respectively used for the first terminal equipment to switch to the plurality of cells. For example, the plurality of cells includes a second cell and a third cell, resources of the second cell are available for the first terminal device to switch to the second cell, and resources of the third cell are available for the first terminal device to switch to the third cell. In some implementations, the resource pool includes resources reserved by a plurality of cells within the second CU for terminal devices within the first CU.

In some implementations, different CUs may correspond to different resource pools. Taking the second CU and the third CU as examples, the resource pool provided by the second CU is a resource pool 1, the resource pool provided by the third CU is a resource pool 2, the resources in the resource pool 1 can be used for switching the terminal device in the first CU to the cell in the second CU, and the resources in the resource pool 2 can be used for switching the terminal device in the first CU to the cell in the third CU.

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

In some implementations, resources allocated to each other's terminal devices between CUs may be included in the resource pool. Taking the first CU and the second CU as examples, the resource pool may include resources allocated by the first CU to the terminal device in the second CU, and resources allocated by the second CU to the terminal device in the first CU. Of course, in some implementations, the resource pool may also include resources allocated by the CU for the terminal devices therein. Taking the first CU and the second CU as examples, the resource pool may include resources allocated by the first CU to the terminal device in the first CU, and resources allocated by the second CU to the terminal device in the second CU.

In some implementations, the resources allocated by the first CU to the terminal device in the first CU may be the same as or different from the resources allocated by the first CU to the terminal device in the second CU, which is not specifically limited in the embodiments of the present application.

In some implementations, resources in the resource pool may be cell-granularity, and allocating resources cell-granularity may increase utilization of the resources. For example, the resource pool includes resources of the second cell, where the resources of the second cell may be used for any terminal device (e.g., any terminal device in the first CU) to switch to use by the second cell.

The types of resources reserved by the multiple cells for the terminal device in the first CU may be the same, or the types of resources reserved by the multiple cells for the terminal device in the first CU may be different, which is not particularly limited in the embodiment of the present application. As an example, the resources reserved by cell 1 may include resources (e.g., preamble, PRACH occasion, etc.) for random access, while the resources reserved by cell 2 may include resources (e.g., CG, CORESET, C-RNTI, key, etc.) for transmitting uplink data. 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.

For example, the resources provided by cell 1 include CG for terminal devices transmitting uplink data. For another example, the resources provided by the cell 2 include CORESET for the terminal device to receive PDCCH or DCI, thereby acquiring DG to transmit uplink data through DG.

In some implementations, the target resource may be selected by the first CU from a pool of resources, e.g., the first CU may select the target resource from resources provided by the second cell.

The second cell is taken as an example, and the second cell provides resources in various manners, which are not particularly limited in the embodiment of the present application. The manner in which the resources are provided by the second cell is described in more detail below.

In some implementations, the resources provided by the second cell may include multiple sets of resources, each of which may include multiple types of resources. Alternatively, the different types of resources are in fixed combination. Taking C-RNTI, CG, CORESET, preamble, PRACH occasion as an example, the first set of resources may include C-RNTI-1, CG-1, CORESET-1, preamble-1, PRACH occasion-1, the second set of resources may include C-RNTI-2, CG-2, CORESET-2, preamble-2, PRACH occasion-2, and so on. When the first CU selects the resources, one set of resources can be selected from multiple sets of resources for the first terminal equipment to perform cell switching.

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

In some embodiments, the target resources include second resources, the second resources belonging to a first type of resources, the second resources being resources selected by the first CU from a first set of resources, the first set of resources being resources of a first type reserved by the second cell for terminal devices within the first CU. Taking the first type of resource as the C-RNTI as an example, the first CU may select one C-RNTI from the set of C-RNTIs for the first terminal device to switch to the second cell.

In some implementations, the first terminal device may switch to the second cell using the target resource in the resource pool. After the first terminal equipment is switched from the first cell to the second cell, the first resource in the target resource meets any one of the following: the first resource is released, and the first resource is used for other terminal equipment in the first CU to switch to the second cell; the first resource cannot be used for switching other terminal devices in the first CU to the second cell; the first resource is used for communication between the first terminal device and the second cell.

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

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 resources in the target resource. The released resources can be used for other terminal equipment, so that the utilization rate of the resources can be improved.

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

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

In some implementations, the first terminal device may determine whether the target resource is a dedicated resource of the first terminal device before receiving the second C-RNTI. The first terminal device determines whether the target resource is a dedicated resource of the first terminal device, which may also be understood as the first terminal device determining whether the target resource is a common resource. If the target resource is a special resource, the target resource is not a public resource; if the target resource is not a dedicated resource, it is indicated that the target resource belongs to a common resource. In some embodiments, if the target resource is a dedicated resource, the first terminal device may further continue to use the target resource (e.g., the first C-RNTI) after switching to the second cell, i.e., the target resource is not released; if the target resource is a common resource, the first terminal device may release the first resource (e.g., the first C-RNTI) in the target resource, and receive the second C-RNTI sent by the second cell, or wait for the second cell to reallocate the C-RNTI.

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 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 avoids significant changes to existing protocols. Taking an example that the terminal device in the first CU includes the terminal device 1 and the terminal device 2, after the terminal device 1 is switched to the second cell, the first resource in the target resource is not used for the terminal device 2 to be switched to the second cell either. If the first CU needs to allocate resources for the terminal device 2, it may select from the pool of resources other than the first resource.

In some implementations, after the first CU allocates resources for the terminal device, the resources of 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 after the first CU allocates the first resource to the first terminal device, the first resource may be deleted from the resource pool.

In some implementations, after the first terminal device switches to the second cell, a first resource of the target resources may be used for communication between the first terminal device and the second cell, that is, the first resource may also be used for subsequent data transmission by the first terminal device and the second cell. In this case, the first resource cannot be used for other terminal devices within the first CU to switch to the second cell.

As one example, the first resource may include a third C-RNTI. After the terminal equipment uses the third C-RNTI to switch to the second cell, the third C-RNTI can be continuously used for communication with the second cell, so that after the switching is finished, the second cell is not required to allocate a new C-RNTI for the first terminal equipment again, and the change of the existing protocol (the change of the C-RNTI is only involved in the switching process in the existing protocol) can be reduced.

For example, after the first terminal device switches to the second cell, the third C-RNTI may be continuously used, and the C-RNTI in the resource pool may be reduced. However, other resources are not reduced, such as CG, CORESET, preamble, PRACH occasion, etc. in the resource pool, and may be used by other terminal devices performing handover.

As another example, the first resource may include C-RNTI, CG, CORESET, a preamble, a PRACH occasion. For example, after the first terminal device switches to the second cell, the third C-RNTI may be continuously used, and the C-RNTI in the resource pool may be reduced. Other resources may be reduced, such as CG, CORESET, preamble, PRACH occasion, etc. That is, the resources used by the first terminal device cannot be used by the terminal device for the subsequent handover.

In some implementations, the first CU may send second indication information to the first terminal device, the second indication information being 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 being 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 will be appreciated that if the first resource is available for communication between the first terminal device and the second cell, it means that the first resource cannot be used for handover of other terminal devices within the first CU to the second cell.

In some implementations, whether the first resource is able to continue to be used may be notified by the second CU. For example, the second CU may send indication information to the first CU to indicate whether the first resource (e.g., C-RNTI) may continue to be used, or to indicate which resources may continue to be used and which resources may not. If the first resource can be used continuously, the first terminal device can use the first resource to communicate with the second cell continuously after accessing the second cell.

The second indication information may be carried in various manners, which are not particularly limited in the embodiment of the present application. For example, the second indication information may be carried in the first information. For another example, the first indication information may be carried in a handover command.

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 within 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 may be released and the first resource may be used for other terminal devices within 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 within 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 may be used for subsequent communications between the first terminal device and the second cell.

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.

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.

The type of the second cell may include cells in which the second cell belongs to the first CU, and cells in which the second cell does not belong to the first CU (e.g., cells 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 a cell within the first CU, the target resource is a dedicated resource.

In some implementations, the first message may include first indication information, where the first indication information is used to indicate a type of the second cell. The type of the second cell may be used to determine whether the target resource is a dedicated resource of the first terminal device. Alternatively, the first terminal device may determine whether the target resource is a dedicated resource of the first terminal device according to the type of the second cell.

In some implementations, the resource type included in the first resource may be determined by the first CU, or may also be determined by the second CU, or may also be predefined by a protocol, and embodiments of the present application are not limited in detail.

The manner in which the first CU indicates the cell type in the embodiment of the present application is not specifically limited. As an example, the first CU may indicate the type of cell explicitly. As another example, the first CU may indicate the type of cell implicitly. Alternatively, the first message may indicate, by means of an implicit indication, whether the target resource is a dedicated resource of the first terminal device. In some implementations, the first message may be a message carrying the first information, or the first information is carried in the first message. The two modes are respectively described below.

In some implementations, the first CU may indicate the type of cell explicitly. For example, the first CU may send first indication information to the first terminal device, or the first message includes first indication information, where the first indication information may be used to indicate whether the second cell is a cell in the first CU.

There are various indication modes of the first indication information, and the embodiment of the present application is not limited thereto. For example, the first indication information includes a first bit, and the value of the first bit may be used to indicate whether the second cell is a cell in the first CU. Or, whether the second cell is a cell in 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, the second cell is indicated to belong to the cell in the first CU; when the value of the first bit is not 0 (e.g., 1), it indicates that the second cell belongs to a cell crossing the CU. Or when the value of the first bit is not 0 (e.g. 1), the second cell belongs to the cell in the first CU; when the value of the first bit is 0, it indicates that the second cell belongs to a cell crossing the CU. The number of bits included in the first bit may be 1 or more.

For example, the first CU may indicate a cell list (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, respectively. Table 1 shows correspondence between 3 cells and types of the 3 cells.

TABLE 1

Cell	First bit
		Cell 1	0
Cell 2	1
		Cell 3	0

As can be seen from table 1, the value of the first bit corresponding to cell 1 is 0, which indicates that cell 1 is a cell in the first CU. The value of the first bit corresponding to cell 2 is 1, which indicates that cell 2 is a cell crossing the CU. The value of the first bit corresponding to the cell 3 is 0, which indicates that the cell 3 is a cell in the first CU.

In some implementations, the first CU may indicate the type of cell implicitly. As one example, whether the first CU is a cell within the first CU may be determined based on a resource type contained by the target resource. For example, if the target resource includes a target type of resource, it indicates that the second cell belongs to a cell that spans the CU; if the target resource does not include the target type of resource, it indicates that the second cell belongs to a cell within the first CU. The target type of resource may be key related information, and of course, the target type of resource may also be other types of resources, which is not specifically limited in the embodiment of the present application. The key related information may include a key and/or a parameter related to the key. The key-related parameters are used to generate the key.

Table 2 shows a correspondence between cells and resource configurations.

TABLE 2

Cell	Resource allocation
		Cell 1	C-RNTI-1, CG-1, CORESET-1, preamble-1, PRACH occasion-1, key-1 related information
Cell 2	C-RNTI-2, CORESET-2, preamble-2, PRACH opportunity-2, key-2 related information
		Cell 3	C-RNTI-3, CORESET-3, preamble-3, PRACH occasion-3

As can be seen from table 2, since the resource configurations of cell 1 and cell 2 include key related information, cell 1 and cell 2 belong to a cell crossing a CU, and since the resource configuration of cell 3 does not include key related information, cell 3 belongs to a cell within a first CU.

In some implementations, the first CU may also indicate the first key-related parameter to the first terminal device. The first terminal device may generate the first key based on the first key related parameter. 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 security of communications between the first terminal device and the second cell.

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

In some implementations, the first terminal device obtains a type of the second cell. The first terminal device may determine whether to update the key according to the type of the second cell. If the second cell belongs to a cell within the first CU, the first terminal device does not need to update the key. If the second cell belongs to a cell within the second CU, the first terminal device updates the key.

If the first terminal device needs to update the key, the first terminal device may update the key according to the key related parameter configured by the first CU and the key used before. For example, the first terminal device may generate the updated key according to the key used previously, the key related parameter, and a preset algorithm.

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

In some implementations, the first resource in the resource pool is reduced after the first terminal device uses the first resource, as described above. In this case, the second CU may allocate the first resource again to satisfy the handover use of the subsequent terminal device.

There are various ways in which the second CU allocates resources, and embodiments of the present application are not limited in this regard. For example, the second CU may periodically allocate the first resource. For another example, the second CU may reallocate the first resource if the number of resources in the resource pool is less than or equal to a preset threshold.

In some implementations, when the first CU configures resources of a plurality of cells to the first terminal device, the first CU may further indicate a type of the plurality of cells to the first terminal device, where the type of the cells may include cells that belong to the first CU and cells that do not belong to the first CU. For example, the first CU may indicate to the first terminal device which cells belong to cells within the first CU and which cells do not belong to cells within the first CU. By indicating the type of the cell to the first terminal device, the first terminal device may be enabled to select an accessed cell according to the type of the cell. For example, the terminal device may preferentially select to access a cell in the first CU, or the first terminal device may preferentially perform cell handover in the CU, so as to reduce the complexity of handover.

The following describes the scheme of the embodiment of the present application in detail by taking the L1/L2 switching as an example and combining three specific examples. It should be noted that the following three examples are only for ease of understanding and are not intended to limit the embodiments of the present application thereto. In addition, in the absence of a conflict, the following three exemplary schemes may be combined with one another.

Example one

Example one describes a scheme in which the target CU indicates a handover resource to the source CU.

Referring to fig. 6, in step S602, the UE transmits an L3 measurement report to the source CU.

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

In step S604, the source CU transmits a handover request preparation to the target CU. The source CU may request handover preparation from the target CU if there are quasi-target cells belonging to the cross-CU among the one or more quasi-target cells. The source CU may indicate to the target CU the identity of one or more target cells.

In step S606, the target CU indicates to the source CU resources within one or more quasi-target cells. If the target CU allows the UE access, resources may be allocated to the UE in one or more quasi-target cells and the source CU may be notified of the corresponding resources.

In step S608, the source CU transmits a handover configuration to the UE. The handover configuration is used to configure resources within one or more quasi-target cells.

In the multiple quasi-target cell sets, all quasi-target cells may be provided by the same target CU, or may be provided by multiple target CUs, or may be provided by a part of target cells, and a part of quasi-target cells may be provided by a source CU.

The source CU may send the handover configuration to the UE through an RRC message or in the form of a MAC CE through a DU.

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

In some implementations, the source CU may explicitly inform the UE of the type of quasi-target cell. For example, the source CU may inform the UE of the type of quasi-target cell in the cell list by one bit. If the value of the bit is 1, the quasi-target cell and the source cell are the same CU cell; if the bit has a value of 1, it indicates that the quasi-target cell belongs to a cell across CUs.

In some implementations, the source CU may implicitly inform the UE of the type of quasi-target cell. For example, if the configuration information of the quasi-target cell includes a key used by the UE in the quasi-target cell, the UE may consider that the quasi-target cell belongs to a cell crossing the CU; if the configuration information of the quasi-target cell does not include a key used by the UE in the quasi-target cell, the UE may consider that the quasi-target cell and the source cell belong to a cell of the same CU.

In step S610, the UE acquires a TA with each quasi-target cell according to the indication of the source DU (or source cell).

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

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

In step S616, the UE accesses the target cell indicated by the source DU (or source cell). Step S616 includes S616a and S616b, and in step S616a, the UE transmits uplink data to the target DU, and in step S616b, the target DU transmits a handover acknowledgement to the UE.

After receiving the uplink data sent by the UE, the target DU may indicate to the target CU that the UE has access in step S618.

In step S620, if the target CU determines that the UE belongs to a handover across CUs, the corresponding source CU is notified that the UE has successfully accessed.

In some implementations, the target CU may determine whether the UE belongs to a UE that is handed off across CUs based on the C-RNTI of the UE and/or the resource location used by the UE to access a cell within the target CU.

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 inform the quasi-target cell to delete the resources allocated for the UE.

In step S624, the source CU may delete resources in the source CU that are prepared for the UE by other cells. After receiving the notification of successful access of the UE, the source CU may perform the following processing according to the quasi-target cell previously prepared for the UE: if the source CU has a quasi-target cell, the source CU can inform the quasi-target cell to delete the resources allocated for the UE; if a quasi-target cell is also present in the other CU, the other CU is informed to delete the resources prepared for the UE.

The resources prepared for the UE may include one or more of the following: C-RNTI, CG, CORESET listening to DG, key x, etc.

Example two and example three describe a scheme in which the first CU selects a handover resource from a resource pool. The second scenario is that the resources after UE use may be released for other UE handover. The scenario of example three is that the resources used by the UE are not available for other UE use. Examples two and three are described below, respectively.

Example two

Referring to fig. 7, in step S702, the CUs prepare resources required for handover for each other' S UEs, i.e., resources prepared for UEs handed over across CUs. In this process, since the switching procedure has not yet been started, there is no role of the source CU, the target CU.

The resources allocated by a CU may be at the granularity of a cell, and the resources allocated by a cell may include one or more of: C-RNTI, CG, CORESET, preamble, PRACH occasion, etc. These resources are common and do not belong to any one particular UE. If the UE is switched across CU, the resources can be used for access, and after the access is successful, the UE releases the resources.

Fig. 7 only shows a scenario in which the target CU provides resource information to the source CU for handover of the UE from a cell in the source CU to a cell in the target CU, it being understood that the source CU may also provide resources to the target CU for handover of the UE from a cell in the target CU to a cell in the source CU.

The type of resources provided by each cell may be the same or different. The resources provided by the cells, if any, include CG for the UE to transmit uplink data. If any, the cell provides CORESET for the UE to acquire DG by receiving PDCCH, so as to transmit uplink data.

In step S704, the UE transmits an L3 measurement report to the source CU.

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.

The source CU selects one or more quasi-target cells for the UE according to the L3 measurement report of the UE and allocates resources for the UE. For quasi-target cells across CUs, the resources provided by the source CU come from the common pool of resources provided by the target CU in step S702. It should be noted that the source CU may arbitrarily combine the resources in the unified cell provided by the target CU. Such as selecting a C-RNTI from a C-RNTI pool, selecting a CG configuration from a CG pool, selecting a CORESET from a CORESET pool, selecting a preamble from a preamble pool, selecting a PRACH from a PRACH occasion, etc.

The type of uplink resources provided by the source cell to the UE may be different. The resources provided by the cells, if any, include CG for the UE to transmit uplink data. If any, the cell provides CORESET for the UE to acquire DG by receiving PDCCH, so as to transmit uplink data.

In step S708, the UE acquires a TA with each quasi-target cell.

In step S710, the UE transmits an L1 measurement report to the source DU (or source cell).

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

In some implementations, the UE determines whether the resources it uses are common or dedicated depending on the type of target cell. Specifically, if the target cell is a cell within the CU, the UE considers its corresponding resources to be dedicated. And for the resource C-RNTI, after the UE is successfully switched, the C-RNTI notified in the L1/L2 switching command can be used for communicating with the target cell. If the target cell is a cell that spans the CU, the UE considers its corresponding resources to be common. For the resource C-RNTI, after the UE is successfully switched, the target cell can wait for the C-RNTI to be reassigned.

The type of the target cell may be indicated to the UE by the source CU, and a specific indication manner may be referred to in the description of example one.

In step S714, the UE accesses the target cell. Step S714 includes S714a and S714b, and in step S714a, the UE transmits uplink data to the target DU, and in step S714b, the target DU transmits a handover acknowledgement to the UE.

In step S716, after the target DU receives the uplink data sent by the UE, it may indicate to the target CU that the UE has been accessed.

In step S718, the target CU indicates to the source CU that the UE access was successful. The target CU may send indication information to the source CU indicating that the UE access was successful. The indication information may include an identification of the UE. The identity of the UE may be a C-RNTI corresponding to the UE. For example, the target CU may inform the source CU of the "C-RNTI XXX's UE access success. The C-RNTI corresponding to the UE can be allocated for the UE by a target cell or allocated for the UE by a source cell.

In step S720, after receiving the indication that the UE is successfully accessed, the source CU may send a new key of the UE to the target CU.

In step S722, the target CU reallocates the C-RNTI for the UE, i.e., the target CU may send the modified C-RNTI to the UE.

In the second scenario, resources interacted between CUs are common, which UE performs a handover across CUs, and these resources can be used. After the use is completed, the corresponding resources are released for the next UE switched across CUs, so that the interaction load between CUs can be greatly reduced.

Example three

Referring to fig. 8, in step S802, CUs allocate resources required for handover to each other' S UEs. In this process, since the switching procedure has not yet been started, there is no role of the source CU, the target CU.

Fig. 8 only shows a scenario in which the target CU provides resource information to the source CU for handover of the UE from a cell in the source CU to a cell in the target CU, it is understood that the source CU may also provide resources to the target CU for handover of the UE from a cell in the target CU to a cell in the source CU.

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 follow. After the UE accesses the cell of the target CU, the target CU does not change the C-RNTI. Unlike the related art scheme, when the target CU allocates C-RNTIs, they are not allocated to a specific UE, but allocated to the source CU, and then the source CU allocates these C-RNTIs to specific handover UEs for use. There are two ways of handling this situation.

The first treatment mode is as follows: the value in the C-RNTI pool is always used after the UE is switched, i.e. the number of C-RNTIs in the C-RNTI pool is reduced. Other resources are still not reduced. Such as CG, CORESET, PRACH occision, etc., may still be allocated for use by UEs for subsequent handover.

The second treatment mode is as follows: the value in the C-RNTI pool is used all the time after the UE is switched, namely the number of C-RNTI in the C-RNTI pool is reduced, and other resources are also reduced. That is, the resources used by the UE cannot be used by other UEs for subsequent handover, such as CG, CORESET, PRACH occision, etc.

The specific processing mode may be determined by the source CU, the target CU, or a protocol.

If the first processing mode is adopted, the C-RNTI pool becomes smaller, so that after a period of time, the reserved C-RNTI needs to be allocated again among CUs. If the second processing mode is adopted, the resource pool becomes smaller after the UE is successfully switched, so that the reserved resource pool needs to be allocated again between CUs after a period of time.

After the UE uses one C-RNTI to switch among CUs, whether the C-RNTI can be used continuously or not can be notified by the source cell. The source cell may inform the UE of this information through a handover configuration or an L1/L2 handover command.

In step S804, the UE transmits an L3 measurement report to the source CU.

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

The source CU selects one or more quasi-target cells for the UE according to the L3 measurement report of the UE and allocates resources for the UE. For quasi-target cells across CUs, the resources provided by the source CU come from the common pool of resources provided by the target CU in step S802. It should be noted that the source CU may arbitrarily combine the resources in the unified cell provided by the target CU. Such as selecting a C-RNTI from a C-RNTI pool, selecting a CG configuration from a CG pool, selecting a CORESET from a CORESET pool, selecting a preamble from a preamble pool, selecting a PRACH from a PRACH occasion pool, etc.

In step S808, the UE acquires a TA with each quasi-target cell.

In step S810, the UE transmits an L1 measurement report to the source DU (or source cell).

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

In step S814, the UE accesses the target cell. Step S814 includes S814a and S814b, and in step S814a, the UE transmits uplink data to the target DU, and in step S814b, the target DU transmits a handover acknowledgement to the UE.

In step S816, after the target DU receives the uplink data sent by the UE, it may indicate to the target CU that the UE has access.

In step S818, the target CU indicates to the source CU that the UE access was successful. The target CU may send indication information to the source CU indicating that the UE access was successful. The indication information may include an identification of the UE. The identity of the UE may be a C-RNTI corresponding to the UE. For example, the target CU may inform the source CU of the "C-RNTI XXX's UE access success. The C-RNTI corresponding to the UE can be allocated for the UE by a target cell or allocated for the UE by a source cell.

In step S820, after receiving the indication that the UE is successfully accessed, the source CU may send a new key of the UE to the target CU.

The method embodiments of the present application are described above in detail with reference to fig. 1 to 8, and the apparatus embodiments of the present application are described below in detail with reference to fig. 9 to 10. It is to be understood that the description of the method embodiments corresponds to the description of the device embodiments, and that parts not described in detail can therefore be seen in the preceding method embodiments.

Fig. 9 is a schematic block diagram of a terminal device provided in an embodiment of the present application. The terminal device 900 shown in fig. 9 may be any of the first terminal devices described above. The terminal device 900 shown in fig. 9 may include a receiving unit 910.

The receiving unit 910 is configured to receive first information sent by a first CU, where the first information is used to indicate a target resource, where the target resource is used for the first terminal device to switch from a first cell to a second cell, where the first cell is a cell in the first CU, and the second cell is a cell in the second CU.

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

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

In some possible implementations, after the first terminal device switches from the first cell to the second cell, a first resource of 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.

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

In some possible implementations, if the target resource is not a dedicated resource for the first terminal device, a 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.

In some possible implementations, the receiving unit is further configured to: and receiving a first message sent by the first CU to determine whether the target resource is a dedicated resource of the first terminal equipment.

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

In some possible implementations, the first message indicates, by means of an implicit indication, whether the target resource is a dedicated resource of the first terminal device.

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.

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.

In some possible implementations, the receiving unit is further configured to: and receiving second indication information sent by the first CU, wherein the second indication information is used for indicating whether the first resource can be used for communication between the first terminal equipment and the second cell.

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.

In some possible implementations, the first resource is updated by the second cell if the first resource is not available for other terminal devices within the first CU to switch to the second cell.

In some possible implementations, the first resource includes one or more of: C-RNTI, CG, CORESET, preamble, PRACH occasion, key related parameters.

In some possible implementations, the resource pool includes resources reserved by a plurality of cells in the second CU for terminal devices in the first CU.

In some possible implementations, the types of resources reserved by the plurality of cells for the terminal devices in the first CU are the same, or the types of resources reserved by the plurality of cells for the terminal devices in the first CU are different.

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

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

In some possible implementations, when the first CU receives third indication information sent by the second CU, resources reserved by a 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 instruct the first terminal device to switch to the second cell.

In some possible implementations, when the third CU receives fourth indication information sent by the first CU, resources reserved by a 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 instruct the first terminal device to switch to the second cell.

In some possible implementations, after the first terminal device is handed over to the second cell, the receiving unit is further configured to: and receiving a first key related parameter sent by the first CU, wherein the first key related parameter is used for communication between the first terminal equipment and the second cell.

In some possible implementations, the target resource includes one or more of the following resources: C-RNTI, CG, CORESET, preamble, PRACH occasion, key related parameters.

In some possible implementations, the switching manner of the first terminal device from the first cell to the second cell is based on layer 1/layer 2 switching.

In an alternative embodiment, the receiving unit 910 may be a transceiver 1030, and the determining unit and the releasing unit may be a processor 1010. Terminal device 900 can also include memory 1020, as shown in particular in fig. 10.

Fig. 10 is a schematic structural diagram of a communication apparatus of an embodiment of the present application. The dashed lines in fig. 10 indicate that the unit or module is optional. The apparatus 1000 may be used to implement the methods described in the method embodiments above. The apparatus 1000 may be a chip, a terminal device or a network device.

The apparatus 1000 may include one or more processors 1010. The processor 1010 may support the apparatus 1000 to implement the methods described in the method embodiments 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 (central processing unit, CPU). Or the processor may be another general purpose processor, a digital signal processor (DIGITAL SIGNAL processor), an Application SPECIFIC INTEGRATED Circuit (ASIC), an off-the-shelf programmable gate array (field programmable GATE ARRAY, FPGA) or other programmable logic device, a discrete gate or transistor logic device, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The apparatus 1000 may also include one or more memories 1020. The memory 1020 has stored thereon a program that is executable by the processor 1010 to cause the processor 1010 to perform the methods described in the method embodiments above. The memory 1020 may be separate from the processor 1010 or may be integrated within the processor 1010.

The apparatus 1000 may also include a transceiver 1030. The processor 1010 may communicate with other devices or chips through a transceiver 1030. For example, the processor 1010 may transmit and receive data to and from other devices or chips through the transceiver 1030.

The embodiment of the application also provides a computer readable storage medium for storing a program. The computer-readable storage medium may be applied to a terminal or a network device provided in an embodiment of the present application, and the program causes a computer to execute the method performed by the terminal or the network device in the respective embodiments of the present application.

The embodiment of the application also provides a computer program product. The computer program product includes a program. The computer program product may be applied to a terminal or a network device provided in an embodiment of the present application, and the program causes a computer to execute the method executed by the terminal or the network device in the respective embodiments of the present application.

The embodiment of the application also provides a computer program. The computer program can be applied to a terminal or a network device provided in an embodiment of the present application, and cause a computer to perform a method performed by the terminal or the network device in each embodiment of the present application.

It should be understood that the terms "system" and "network" may be used interchangeably herein. In addition, the terminology used herein is for the purpose of describing particular embodiments of the application only and is not intended to be limiting of the application. The terms "first," "second," "third," and "fourth" and the like in the description and in the claims and drawings are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion.

In the embodiment of the present application, the "indication" may be a direct indication, an indirect indication, or an indication having an association relationship. For example, a indicates B, which may mean that a indicates B directly, e.g., B may be obtained by a; it may also indicate that a indicates B indirectly, e.g. a indicates C, B may be obtained by C; it may also be indicated that there is an association between a and B.

In the embodiment of the application, "B corresponding to A" means that B is associated with A, from which B can be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may also determine B from a and/or other information.

In the embodiment of the present application, the term "corresponding" may indicate that there is a direct correspondence or an indirect correspondence between the two, or may indicate that there is an association between the two, or may indicate a relationship between the two and the indicated, configured, etc.

In the embodiment of the present application, the "pre-defining" or "pre-configuring" may be implemented by pre-storing corresponding codes, tables or other manners that may be used to indicate relevant information in devices (including, for example, terminal devices and network devices), and the present application is not limited to the specific implementation manner thereof. Such as predefined may refer to what is defined in the protocol.

In the embodiment of the present application, the "protocol" may refer to a standard protocol in the communication field, for example, may include an LTE protocol, an NR protocol, and related protocols applied in a future communication system, which is not limited in the present application.

In the embodiment of the present application, the term "and/or" is merely an association relationship describing the association object, which indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In various embodiments of the present application, the sequence number of each process does not mean the sequence of execution, and the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may 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 loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be read by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., digital versatile disk (digital video disc, DVD)), or a semiconductor medium (e.g., solid State Disk (SSD)), etc.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of wireless communication, comprising:

The first terminal equipment receives first information sent by the first centralized unit CU, wherein the first information is used for indicating target resources, the target resources are used for switching the first terminal equipment 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.

2. The method of claim 1, wherein the target resource is selected by the first CU from a pool of resources or the target resource is configured by the second CU to the first CU.

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

4. A method according to claim 3, wherein after the first terminal device has handed over from the first cell to the second cell, a first one of the target resources satisfies any one of:

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.

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

6. The method of claim 4, wherein if the target resource is not a dedicated resource for the first terminal device, a first resource of the target resources is released and the first resource is used for other terminal devices within the first CU to handover to the second cell; or alternatively

7. The method according to claim 5 or 6, characterized in that the method further comprises:

And the first terminal equipment receives a first message sent by the first CU to determine whether the target resource is a special resource of the first terminal equipment.

8. The method according to any of claims 1-7, wherein 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 by means of an implicit indication whether the target resource is a dedicated resource of the first terminal device.

10. The method according to claim 5 or 6, wherein whether the target resource is a dedicated resource of the first terminal device is determined based on a resource type comprised by the target resource.

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

12. The method according to any one of claims 4-11, further comprising:

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 of claim 12, wherein 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 of claims 4 or 5, wherein the first resource is updated by the second cell if the first resource is not available for handover of other terminal devices within the first CU to the second cell.

15. The method of any of claims 4-14, wherein the first resource comprises one or more of: the cell radio network temporary identity C-RNTI, the configuration grant CG, the control resource set CORESET, the preamble, the physical random access channel PRACH occasion, the key related parameters.

16. The method according to any of claims 3-15, wherein the resource pool comprises resources reserved for terminal devices within the first CU by a plurality of cells within the second CU.

17. The method of claim 16, wherein the plurality of cells reserve the same type of resources for terminal devices within the first CU or the plurality of cells reserve different types of resources for terminal devices within the first CU.

18. The method according to claim 16 or 17, wherein the target resources comprise second resources belonging to a first type of resources, the second resources being resources selected by the first CU from a first set of resources reserved by the second cell for terminal devices within the first CU.

19. The method of claim 2, wherein the target resource is configured by the second CU to the first CU.

20. The method of claim 19, wherein resources reserved by a third cell in the first CU for the first terminal device are released by the first CU if the first CU receives third indication information sent by the second CU, wherein the third indication information is used to instruct the first terminal device to switch to the second cell.

21. The method of claim 19, wherein resources reserved by a fourth cell in the third CU for the first terminal device are released by the third CU if the fourth indication information sent by the first CU is received by the third CU, wherein the fourth indication information is used to instruct the first terminal device to switch to the second cell.

22. The method according to any of claims 1-21, characterized in that after the first terminal device is handed over to the second cell, the method further comprises:

the first terminal device receives a first key related parameter sent by the first CU, where the first key related parameter is used for communication between the first terminal device and the second cell.

23. The method of any one of claims 1-22, wherein the target resource comprises one or more of the following resources: C-RNTI, CG, CORESET, preamble, PRACH occasion, key related parameters.

24. The method according to any of claims 1-23, wherein the manner of handover 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, comprising:

the receiving unit is configured to receive first information sent by the 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, where 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 of claim 25, wherein the target resource is selected by the first CU from a pool of resources or the target resource is configured by the second CU to the first CU.

27. The terminal device of claim 26, wherein the target resource is selected by the first CU from a resource pool comprising resources reserved by the second cell for terminal devices within the first CU.

28. The terminal device of claim 27, wherein after the first terminal device is handed over from the first cell to the second cell, a first resource of the target resources satisfies any one of:

29. The terminal device of claim 28, wherein if the target resource is a dedicated resource for the first terminal device, then a first resource of the target resources cannot be used for handover of other terminal devices within the first CU to the second cell.

30. The terminal device according to claim 28, wherein if the target resource is not a dedicated resource for the first terminal device, a first resource of the target resources is released and the first resource is used for handover of other terminal devices within the first CU to the second cell; or alternatively

31. The terminal device according to claim 29 or 30, wherein the receiving unit is further configured to:

And receiving a first message sent by the first CU to determine whether the target resource is a dedicated resource of the first terminal equipment.

32. The terminal device according to any of the claims 25-31, wherein 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 of claim 31, wherein the first message indicates whether the target resource is a dedicated resource for the first terminal device by means of an implicit indication.

34. A terminal device according to claim 29 or 30, wherein whether the target resource is a dedicated resource of the first terminal device is determined based on a type of resource comprised by the target resource.

35. The terminal device of claim 34, wherein whether the target resource is a dedicated resource for the first terminal device is determined based on whether the target resource includes a key.

36. The terminal device according to any of the claims 28-35, wherein the receiving unit is further configured to:

and receiving second indication information sent by the first CU, wherein the second indication information is used for indicating whether the first resource can be used for communication between the first terminal equipment and the second cell.

37. The terminal device of 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 of the claims 28 or 29, wherein the first resource is updated by the second cell if the first resource is not available for handover of other terminal devices within the first CU to the second cell.

39. The terminal device according to any of claims 28-38, wherein the first resource comprises one or more of: the cell radio network temporary identity C-RNTI, the configuration grant CG, the control resource set CORESET, the preamble, the physical random access channel PRACH occasion, the key related parameters.

40. The terminal device according to any of the claims 27-39, wherein the resource pool comprises resources reserved for terminal devices in the first CU by a plurality of cells in the second CU.

41. The terminal device of claim 40, wherein the types of resources reserved by the plurality of cells for terminal devices within the first CU are the same or the types of resources reserved by the plurality of cells for terminal devices within the first CU are different.

42. The terminal device of claim 40 or 41, wherein the target resource comprises a second resource, the second resource being of a first type of resource, the second resource being a resource selected by the first CU from a first set of resources reserved by the second cell for terminal devices within the first CU.

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

44. The terminal device of claim 43, wherein resources reserved for the first terminal device by a third cell in the first CU are released by the first CU if the first CU receives third indication information sent by the second CU, wherein the third indication information is used to instruct the first terminal device to switch to the second cell.

45. The terminal device of claim 43, wherein resources reserved for the first terminal device by a fourth cell in the third CU are released by the third CU if the fourth indication information sent by the first CU is received by the third CU, wherein the fourth indication information is used to instruct the first terminal device to switch to the second cell.

46. The terminal device according to any of the claims 25-45, wherein after the first terminal device is handed over to the second cell, the receiving unit is further configured to:

And receiving a first key related parameter sent by the first CU, wherein the first key related parameter is used for communication between the first terminal equipment and the second cell.

47. The terminal device of any of claims 25-46, wherein the target resource comprises one or more of the following: C-RNTI, CG, CORESET, preamble, PRACH occasion, key related parameters.

48. The terminal device according to any of the claims 25-47, wherein the handover of the first terminal device from the first cell to the second cell is based on layer 1/layer 2 handover.

49. A terminal device, characterized in that it is a first terminal device, comprising a transceiver, a memory for storing a program, and a processor for calling the program in the memory and controlling the transceiver to receive or transmit signals for causing the terminal to perform the method according to any of claims 1-24.