Method and apparatus for wireless communication

Abstract

Provided are a method and device for wireless communication. The method comprises: a first terminal device determines whether to initiate an advanced uplink synchronization process to a first LTM candidate cell according to a first condition; wherein the first condition is associated with one or more of the following: an L1 measurement result of an LTM candidate cell; the position of the terminal device; a first timer; the moving speed of the terminal equipment; and determining whether the TA value of the LTM candidate cell is known. In the embodiments of the present application, a terminal device can initiate an advanced uplink synchronization process with an LTM candidate cell through a trigger condition (i.e., a first condition) of advanced uplink synchronization; therefore, under the condition that the terminal equipment does not report the L1 measurement result, or the network equipment does not trigger the advanced uplink synchronization and does not indicate the advanced uplink synchronization resource, the advanced uplink synchronization process of the terminal equipment and the LTM candidate cell is realized.

Description

Method and apparatus for wireless communication Technical Field

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

[0002] Layer 1 / Layer 2-triggered mobility (LTM) enables users to establish early uplink synchronization with candidate cells. This early uplink synchronization is triggered and instructed by the source cell's Layer 1 (L1) measurement results. In the future, users may no longer need to report L1-based measurement results. In this case, achieving early uplink synchronization between users and candidate cells is a pressing issue.

[0003] Summary of the Invention

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

[0005] In a first aspect, a method for wireless communication is provided, the method comprising: a first terminal device determines whether to initiate an early uplink synchronization process to a first LTM candidate cell based on a first condition; wherein the first condition is associated with one or more of the following: an L1 measurement result of the LTM candidate cell; the location of the terminal device; a first timer; a moving speed of the terminal device; and whether the TA value of the LTM candidate cell is known.

[0006] In a second aspect, a method for wireless communication is provided, the method comprising: a first terminal device sends a random access request to a network device, the random access request being used to perform uplink synchronization with an LTM candidate cell in advance, the random access request being associated with a first random access resource, the first random access resource being one of the following: a CFRA resource; a two-step CBRA resource; and a four-step CBRA resource.

[0007] According to a third aspect, a method for wireless communication is provided, the method comprising: a network device sends first configuration information to a first terminal device, the first configuration information is used to determine a first condition, the first condition is used to determine whether to initiate an early uplink synchronization process to a first LTM candidate cell; wherein the first condition is associated with one or more of the following: an L1 measurement result of the LTM candidate cell; the location of the terminal device; a first timer; a moving speed of the terminal device; and whether the TA value of the LTM candidate cell is known.

[0008] In a fourth aspect, a method for wireless communication is provided, the method comprising: a network device receives a random access request sent by a first terminal device, the random access request being used to perform uplink synchronization with an LTM candidate cell in advance, the random access request being associated with a first random access resource, the first random access resource being one of the following: a CFRA resource; a two-step CBRA resource; and a four-step CBRA resource.

[0009] In a fifth aspect, a terminal device is provided, which is a first terminal device, and the terminal device includes: a determination unit, used to determine whether to initiate an early uplink synchronization process to a first LTM candidate cell based on a first condition; wherein the first condition is associated with one or more of the following: the L1 measurement result of the LTM candidate cell; the location of the terminal device; a first timer; the moving speed of the terminal device; and whether the TA value of the LTM candidate cell is known.

[0010] In the sixth aspect, a terminal device is provided, which is a first terminal device, and the terminal device includes: a first sending unit, used to send a random access request to a network device, the random access request is used to perform uplink synchronization with the LTM candidate cell in advance, the random access request is associated with a first random access resource, and the first random access resource is one of the following: CFRA resource; two-step CBRA resource; and four-step CBRA resource.

[0011] In the seventh aspect, a network device is provided, including: a sending unit, used to send first configuration information to a first terminal device, the first configuration information is used to determine a first condition, and the first condition is used to determine whether to initiate an early uplink synchronization process to a first LTM candidate cell; wherein the first condition is associated with one or more of the following: the L1 measurement result of the LTM candidate cell; the location of the terminal device; the first timer; the moving speed of the terminal device; and whether the TA value of the LTM candidate cell is known.

[0012] In the eighth aspect, a network device is provided, including: a first receiving unit, used to receive a random access request sent by a first terminal device, the random access request is used to perform uplink synchronization with the LTM candidate cell in advance, the random access request is associated with a first random access resource, and the first random access resource is one of the following: CFRA resource; two-step CBRA resource; and four-step CBRA resource.

[0013] In the ninth aspect, a terminal device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the terminal device executes part or all of the steps in the method of the first aspect or the second aspect.

[0014] In the tenth aspect, a network device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the network device executes part or all of the steps in the method of the third aspect or the fourth aspect.

[0015] In an eleventh aspect, an embodiment of the present application provides a communication system, which includes the above-mentioned terminal device and / or network device. In another possible design, the system may also include other devices that interact with the terminal device or network device in the solution provided in the embodiment of the present application.

[0016] In the twelfth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and the computer program enables a terminal device to execute part or all of the steps in the method of the first aspect or the second aspect above.

[0017] In the thirteenth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and the computer program enables the network device to execute part or all of the steps in the method of the third aspect or the fourth aspect above.

[0018] In a fourteenth aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a terminal device to perform some or all of the steps of the method of the first or second aspect described above. In some implementations, the computer program product may be a software installation package.

[0019] In a fifteenth aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a network device to perform some or all of the steps of the method of the third or fourth aspect. In some implementations, the computer program product may be a software installation package.

[0020] In the sixteenth aspect, an embodiment of the present application provides a chip comprising a memory and a processor, wherein the processor can call and run a computer program from the memory to implement part or all of the steps described in the method of any one of the first to fourth aspects above.

[0021] In an embodiment of the present application, based on the triggering condition of early uplink synchronization (i.e., the first condition), the terminal device can initiate an early uplink synchronization process with the LTM candidate cell, thereby helping the terminal device to achieve an early uplink synchronization process with the LTM candidate cell without reporting the L1 measurement result, or when the network device does not trigger the early uplink synchronization and does not indicate the early uplink synchronization resource. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic diagram of a wireless communication system used in an embodiment of the present application.

[0023] FIG2 is a schematic flow chart of a cell handover process based on L3 measurement / signaling.

[0024] FIG3 is a schematic diagram of a conditional switching process.

[0025] FIG4 is a schematic diagram of a cell handover process based on LTM.

[0026] FIG5 is a schematic flow chart of a method for wireless communication provided in an embodiment of the present application.

[0027] FIG6 is a flowchart of a method for wireless communication provided in another embodiment of the present application.

[0028] FIG7 is a schematic structural diagram of a terminal device provided in an embodiment of the present application.

[0029] FIG8 is a schematic structural diagram of another terminal device provided in an embodiment of the present application.

[0030] FIG9 is a schematic diagram of the structure of a network device provided in an embodiment of the present application.

[0031] FIG10 is a schematic diagram of the structure of another network device provided in an embodiment of the present application.

[0032] FIG11 is a schematic structural diagram of a device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] The technical solution in this application will be described below with reference to the accompanying drawings.

[0034] Figure 1 illustrates a wireless communication system 100 used in an embodiment of the present application. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographic area and may communicate with the terminal device 120 within the coverage area.

[0035] FIG1 exemplarily shows a network device and two terminals. Optionally, the wireless communication system 100 may include multiple network devices and each network device may include other numbers of terminal devices within its coverage area, which is not limited in the embodiments of the present application.

[0036] Optionally, the wireless communication system 100 may further include one or more core network devices, which is not limited in this embodiment of the present application. Exemplarily, the core network device may include one or more of the following: an access and mobility management function (AMF) entity, a session management function (SMF) entity, a user plane function (UPF) entity, etc.

[0037] The AMF entity, for example, may also be called an AMF network element or an AMF functional entity. The AMF entity may be responsible for access management and mobility management of terminal devices.

[0038] An SMF entity, for example, may also be called an SMF network element or an SMF functional entity. An SMF entity may be responsible for session management (such as establishing a user session), allocating and managing Internet Protocol (IP) addresses of terminal devices, and the like.

[0039] A UPF entity, for example, may also be referred to as a UPF network element or UPF functional entity. A UPF entity may be a user plane functional entity, i.e., a user plane gateway. A UPF entity may be used for packet routing and forwarding, or for quality of service (QoS) processing of user plane data. User data may be connected to external networks, such as a data network (DN), through the UPF entity.

[0040] Optionally, the wireless communication system 100 may further include other network entities such as a network controller, which is not limited in the embodiments of the present application. It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) systems or new radio (NR), long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD), etc. The technical solutions provided in this application can also be applied to future communication systems, such as sixth generation mobile communication systems, satellite communication systems, and the like.

[0041] The terminal device in the embodiments of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiments of the present application may refer to a device that provides voice and / or data connectivity to a user and can be used to connect people, objects and machines, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. Optionally, the UE can be used to act as a base station. For example, the UE can act as a scheduling entity that provides sidelink signals between UEs in V2X or D2D, etc. For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and smart home devices communicate without relaying the communication signal through the base station.

[0042] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. A base station can broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmission point (TRP), transmission point (TP), master station MeNB, secondary station SeNB, multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. A base station can also refer to a communication module, modem or chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs base station functions in device-to-device D2D, vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. The base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form used by the network equipment.

[0043] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0044] In some deployments, the network device in the embodiments of the present application may refer to a CU or a DU, or the network device may include a CU and a DU. The gNB may also include an AAU.

[0045] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0046] It should be understood that all or part of the functions of the communication device in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (such as a cloud platform).

[0047] With the increasing demand for speed, latency, high-speed mobility, and energy efficiency, coupled with the increasing diversity and complexity of future services, the 3rd Generation Partnership Project (3GPP), an international standards organization, has begun developing 5G. Key 5G application scenarios include enhanced mobile broadband (eMBB), ultra reliable low latency communications (URLLC), and massive machine-type communications (mMTC).

[0048] For ease of understanding, the communication process involved in the embodiments of the present application is introduced below.

[0049] Random access process

[0050] The terminal device can establish a connection with the cell and obtain uplink synchronization information by initiating a random access process. Random access can include a four-step random access process and a two-step random access process. The random access process can also be divided into a contention-based random access (CBRA) process and a non-contention-based random access (CFRA) process. Among them, the contention-based random access process can include a four-step random access process and a two-step random access process, and the non-contention-based random access process can include a four-step random access process and a two-step random access process.

[0051] The four-step random access procedure may include steps 1 to 4.

[0052] In step 1, the terminal device sends a random access request to the network device. The random access request may include a random access preamble. The random access request may also be referred to as the first message or message 1 (Msg1) in the random access process.

[0053] In step 2, after detecting the random access preamble sent by the terminal device, the network device sends a random access response (RAR) to the terminal device. The RAR message can also be called the second message or message 2 (Msg2) in the random access process.

[0054] In step 3, the terminal device sends Message 3 (Msg3) to the network device. Message 3 can be used to notify the network device of the event that triggered the random access process. For example, if the event is the initial access random process, Message 3 will carry the terminal device identifier and establishment cause; if the event is radio resource control (RRC) re-establishment, it will carry the connected terminal device identifier and establishment cause.

[0055] In step 4, the network device sends a message 4 (Msg4) to the terminal device. Message 4 can be used for conflict resolution, and therefore, message 4 can also be called a contention resolution message.

[0056] In order to reduce the delay overhead, two-step random access is introduced. The two-step random access process may include step 1 and step 2.

[0057] In step 1, the terminal device sends a message A (MsgA) to the network device. Message A may include message 1 and message 3 in the four-step random access process.

[0058] In step 2, the network device sends a message B (MsgB), namely a random access response, to the terminal device. Message B can be used for contention resolution.

[0059] Cell switching

[0060] Cell handover (HO) aims to improve the continuity of service provided by the communication system to terminal devices. In wireless communication systems, terminal devices can move from one cell (also known as the "source cell") to another cell (also known as the "target cell"). Generally, cell handovers can be divided into two types: traditional handover mechanisms and conditional handover mechanisms.

[0061] In the embodiment of the present application, the source cell may refer to a cell that provides services to the terminal device before the handover, and the target cell may refer to a cell that provides services to the terminal device after the handover.

[0062] It should be understood that a cell may refer to a coverage area of ​​a network device, i.e., a cell corresponds to a network device. In other words, in the embodiment of the present application, a source cell corresponds to a source network device (e.g., a source base station), and a target cell corresponds to a target network device (e.g., a target base station).

[0063] It should also be understood that in the embodiments of the present application, "source cell" can be replaced by "network equipment to which the source cell belongs" and "target cell" can be replaced by "network equipment to which the target cell belongs".

[0064] It should also be understood that in the embodiments of the present application, the source cell and the target cell may belong to the same network device (such as a base station), or the source cell and the target cell may belong to different network devices. In other words, in some embodiments, the source network device and the target network device may refer to the same network device. The embodiments of the present application are not limited to this.

[0065] Traditional switching

[0066] In wireless communication systems (such as LTE or NR systems), when a terminal device using network services moves from one cell to another, or due to reasons such as wireless transmission load adjustment, activation operation maintenance, and equipment failure, in order to maintain the continuity of communication and service quality of the terminal device, the system needs to transfer the communication link between the terminal device and the original cell to the new cell, that is, perform a cell handover process. This cell handover mechanism can also be called traditional handover.

[0067] The following briefly introduces the cell switching process based on L3 measurement / signaling with reference to FIG. 2 .

[0068] In step 1, the source network device sends a handover request to the target network device.

[0069] The source network device may trigger a handover based on the L3 measurement result reported by the terminal, and send a handover request to the target cell via the Xn interface.

[0070] In step 2, the target network device sends a handover request acknowledgement to the source network device.

[0071] The target network device may accept the handover request from the source network device and provide the RRC configuration of the target network device as part of the handover request confirmation and feed it back to the source network device.

[0072] In step 3, the source network device sends an RRC reconfiguration message to the terminal device.

[0073] The source network device sends an RRC reconfiguration message to the terminal device to instruct the terminal device to initiate a handover process, as well as an RRC configuration message for accessing the target cell.

[0074] In step 4, the terminal device sends an RRC reconfiguration complete message to the target network device.

[0075] The terminal device accesses the target cell and sends an RRC configuration complete message to the target cell. In order to establish uplink synchronization with the target cell, the terminal device needs to initiate a random access process to the target cell.

[0076] Conditional handover (CHO)

[0077] The goal of conditional switching is mainly to improve the reliability and robustness of user switching, so as to solve the problem of late switching due to too long switching preparation time during the switching process, or the problem of switching failure caused by a sharp drop in the channel quality of the source cell during the switching process. The core idea of ​​conditional switching is to pre-configure the switching command content to the terminal device in advance. When specific conditions are met, the terminal device can autonomously execute the configuration in the switching command and directly initiate switching access to the target cell that meets the conditions. Since the terminal device no longer triggers measurement reporting when the switching conditions are met, and the terminal device has obtained the configuration in the switching command in advance, the problem of the aforementioned measurement reporting and switching command not being correctly received is solved. Especially for high-speed mobile scenarios or scenarios with rapid signal fading in the switching band, conditional switching can greatly improve the switching success rate.

[0078] The handover process can generally be divided into three phases: handover preparation, handover execution, and handover completion. The following briefly describes the conditional handover process, with reference to Figure 3. The process shown in Figure 3 can be performed by the terminal device, the source network device (i.e., the network device corresponding to the source cell), the target network device (i.e., the network device corresponding to the target cell), other potential target network devices, the AMF, and the UPF(s). For example, the source network device can be the source gNB (source gNB). The target network device can be the target gNB (target gNB). Other potential target network devices can be other potential target gNB(s).

[0079] Phase 1: Switchover Preparation (Steps 1 to 7)

[0080] In step 1, measurement control and reporting are performed between the source network device and the terminal device. Specifically, the source network device triggers the terminal device to perform neighboring cell measurements, so that the terminal device can measure the neighboring cells and report the measurement results to the source network device.

[0081] Before step 1, user data can be transmitted between the terminal device and the source network device. User data can be transmitted between the source network device and the UPF.

[0082] As shown in FIG3 , before step 1, the first stage may further include step 0. In step 0, the AMF provides mobility control information (mobility control information provided by the AMF).

[0083] In step 2, the source network device evaluates the measurement results reported by the terminal device and decides whether to trigger a handover (CHO decision).

[0084] In step 3, if the source network device decides to trigger a handover, it may send a handover request to the target network device and other candidate target network devices.

[0085] In step 4, after receiving the handover request sent by the source network device, the target network device and other candidate target network devices may start admission control and perform wireless resource configuration according to the service information carried by the source network device.

[0086] In step 5, the target network device and other candidate target network devices send a handover request acknowledgement message to the source network device. The handover request acknowledgement message includes RRC reconfiguration messages of the target network device and other candidate target network devices.

[0087] In step 6, after receiving the handover request confirmation messages from the target network device and other candidate target network devices, the source network device may send RRC reconfiguration messages (RRC reconfiguration) of the target network device and other candidate target network devices to the terminal device.

[0088] In step 7, the terminal device sends an RRC reconfiguration completion message to the source network device. At this point, the handover preparation phase is completed.

[0089] Phase 2: Handover Execution (Steps 7a to 8)

[0090] In step 7a, the terminal device evaluates the CHO conditions and performs an early status transfer based on the evaluation results. If the CHO conditions are met, the terminal device detaches from the old cell and synchronizes to the new cell.

[0091] In step 8, the conditional handover is completed (CHO handover completion).

[0092] Phase 3: Handover Completed (Steps 8a to 8c)

[0093] In step 8a, the target network device sends a handover success message to the source network device.

[0094] In step 8b, the source network device may forward the buffered data, the data packets being transmitted, the associated sequence number (SN) of the data, etc. to the target network device via SN status transfer.

[0095] In step 8c, the source network device sends a handover cancel message to the target network device and other candidate target network devices.

[0096] In some embodiments, the third stage may also include steps 9 to 12 in Figure 9.2.3.2.1-1 of the conditional switching section in the protocol, which will not be repeated here for the sake of brevity.

[0097] LTM

[0098] The handover process in the related art is triggered by L3 signaling (RRC reconfiguration). In order to further reduce the delay of the L3 handover process, the R18 mobility project will support cell handover triggered by L1 / L2 signaling, namely LTM.

[0099] The LTM-based cell handover process can be divided into four stages: LTM preparation, pre-synchronization, LTM execution, and LTM completion. The following briefly describes the LTM-based cell handover process with reference to Figure 4.

[0100] Phase 1: LTM Preparation (Step 1-Step 3)

[0101] In step 1, the terminal device in the RRC connected state reports a measurement report to the network device.

[0102] The measurement report in this step is based on L3 measurement. The network device can determine to initiate the LTM process based on the measurement result and trigger candidate cell preparation.

[0103] In step 2, the network device sends an RRC reconfiguration message to the terminal device.

[0104] The network device may send an RRC message (ie, an RRC reconfiguration message) containing LTM candidate cell configuration to the terminal device, where the number of candidate cells is one or more.

[0105] In step 3, the terminal device stores the LTM candidate cell configuration and feeds back a reconfiguration completion message (ie, an RRC reconfiguration complete message) to the network device.

[0106] Phase 2: Early Synchronization (Steps 4a and 4b)

[0107] In step 4a, the terminal device performs downlink synchronization with the candidate cell.

[0108] In step 4b, the terminal device performs uplink synchronization with the candidate cell.

[0109] Before receiving the LTM cell switching command, the terminal device can synchronize uplink / downlink with the candidate cell in advance to reduce the interruption delay of the switching process.

[0110] Phase 3: LTM Execution (Step 5-Step 7)

[0111] In step 5, the terminal device performs L1 measurement on each candidate cell and reports the L1 measurement result to the network device.

[0112] In step 6, the network device determines a target cell based on the L1 measurement result reported by the terminal device, and instructs the terminal device to switch to the target cell through a media access control element (MAC CE).

[0113] In step 7, if the terminal device currently does not have a valid timing advance (TA) of the target cell, then after receiving the LTM handover indication, the terminal device initiates a random access process to the target cell.

[0114] Phase 4: LTM Completion (Step 8)

[0115] At step 8, the LTM is completed.

[0116] The mobility topic in Release 18 primarily discusses LTM triggered by the network side. Specifically, the terminal device first reports the L1 measurement results of the candidate cell (beam) to the network device. The network device then determines the target cell based on the received L1 measurement results and sends a cell handover instruction to the terminal device via the MAC CE. The delay required to report the measurement results and issue the cell handover instruction can increase the probability of handover failure. To further enhance the robustness of the LTM process, LTM triggered by the terminal device, or conditional LTM, may be considered in the research of the next protocol version (R19).

[0117] R18LTM supports the terminal device to establish uplink synchronization with the candidate cell in advance. The early uplink synchronization process is triggered by the physical downlink control channel (PDCCH) order sent by the source cell. The terminal device sends a preamble to the candidate cell based on the PDCCH order. Unlike the traditional random access process, the terminal device does not need to monitor the RAR after completing the preamble transmission. During the LTM execution phase, the network equipment sends the TA information of the target cell to the terminal device through the LTM cell handover command. This can save the terminal device from the handover interruption delay caused by obtaining the target cell TA through the random access process after receiving the handover command.

[0118] The source cell determines when and to which candidate cell the terminal device initiates early uplink synchronization based on the L1 measurement results reported by the terminal device. However, in the future, the terminal device may not need to report L1-based measurement results. For example, conditional LTM may not require the terminal device to report L1 measurement results for candidate cells to the network equipment. In this case, how to achieve early uplink synchronization between the terminal device and the candidate cell is an urgent problem to be solved.

[0119] How to achieve early uplink synchronization between the terminal device and the candidate cell may include, for example, how to trigger the terminal device to establish uplink synchronization with the candidate cell in advance. FIG5 shows a method for wireless communication provided by an embodiment of the present application to solve the above problem.

[0120] The method shown in FIG. 5 may include step S510 .

[0121] In step S510, the first terminal device determines whether to initiate an early uplink synchronization process to the first LTM candidate cell according to a first condition.

[0122] The first LTM candidate cell may be one of the LTM candidate cells configured by the network device for the terminal device. For example, the information of the LTM candidate cell may be carried in an RRC message.

[0123] The early uplink synchronization mentioned here may refer to an uplink synchronization process between the terminal device and the LTM candidate cell before determining the target cell.

[0124] In some embodiments, the first condition may be associated with one or more of: an L1 measurement result of the LTM candidate cell; a location of the terminal device; a first timer; a moving speed of the terminal device; and whether the TA value of the LTM candidate cell is known.

[0125] As mentioned above, during the execution of conditional LTM, the terminal device may perform L1 measurement on the candidate cell. In some embodiments, the first condition may be associated with the L1 measurement result of the LTM candidate cell. For example, the L1 measurement result of the LTM candidate cell may include the cell measurement result of the LTM candidate cell, and may also include the beam measurement result of the LTM candidate cell, that is, the first condition may be associated with the cell measurement result and / or beam measurement result of the LTM candidate cell. For another example, the L1 measurement result of the LTM candidate cell may include the reference signal received power (RSRP) measurement result, that is, the first condition may be associated with the RSRP measurement result of the LTM candidate cell, such as the first condition may be associated with the RSRP measurement result of the cell and / or beam of the candidate cell.

[0126] Compared with the scenario in which the terminal device obtains the TA of the first LTM candidate cell, the scenario in which the terminal device accesses or prepares to access the first LTM candidate cell may change. The above-mentioned scenario changes, such as changes in the location of the terminal device, may cause the TA obtained by the terminal device to be unsuitable for the scenario in which the terminal device accesses the first LTM candidate cell, or there is no valid TA value for the candidate cell when the terminal device accesses or prepares to access the first LTM candidate cell. Therefore, the first condition may be associated with the scenario in which the terminal device obtains the TA and / or the scenario in which the terminal device accesses the first LTM candidate cell. Based on this, the terminal device may initiate an early uplink synchronization process to the first LTM candidate cell when the TA may not be applicable to the current scenario, or re-trigger the terminal device to perform uplink synchronization with the first LTM candidate cell in advance, thereby helping to avoid the impact of the above-mentioned scenario changes on the TA, and further helping to improve the accuracy of the TA.

[0127] The above-mentioned scene change may include, for example, a change in the location of the terminal device. Therefore, the first condition may be associated with the location of the terminal device. For example, the first condition may be associated with the location change of the terminal device to avoid the impact of the location change of the terminal device on the TA.

[0128] In some embodiments, the scene change may be affected by the moving speed of the terminal device. For example, when the terminal device moves faster, the scene change is more likely to occur. Therefore, the first condition may be associated with the moving speed of the terminal device.

[0129] In some embodiments, the first condition can be associated with a first timer. For example, after a certain period of time has passed since the terminal device acquired the TA of the first LTM candidate cell, the scenario in which the terminal device is located may change. Therefore, associating the first condition with the first timer can prevent the impact of changes in the scenario in which the terminal device is located on the TA. Furthermore, associating the first condition with the first timer can prevent the impact of various changes in the scenario in which the terminal device is located on the TA, and facilitates implementation.

[0130] In some embodiments, the first condition may be associated with whether the TA value of the LTM candidate cell is known. If the TA value of the LTM candidate cell is known, the terminal device may not initiate an uplink synchronization process to the first LTM candidate cell to save overhead.

[0131] The following will provide a detailed introduction to various situations of the first condition provided in the embodiments of the present application with reference to specific examples.

[0132] In some embodiments, the aforementioned first condition is associated with the location of the terminal device, which may include associating the first condition with the current location of the terminal device and / or the reference location of the terminal device.

[0133] Based on the above analysis, it can be known that the reference position of the terminal device may be, for example, the position where the terminal device is located when it receives the TA of the LTM candidate cell.

[0134] For another example, the reference position of the terminal device may also include the position of the terminal device when executing LTM. As an example, in some cases, the terminal device may perform multiple switching in the LTM candidate cell within a certain period of time, that is, the current service cell of the terminal device may be a cell in the LTM candidate cell. In this case, when the terminal device accesses another candidate cell from the current service cell through LTM, the TA value of the current service cell can be saved so that the terminal device can use it when returning to the cell again. In other words, the TA value is obtained when the terminal device executes LTM, or in other words, the TA value corresponds to the position of the terminal device when executing LTM.

[0135] In some embodiments, when the position difference between the current position of the terminal device and the reference position is large, the TA of the first LTM candidate cell acquired by the terminal device may not be applicable to the scenario the terminal device is currently in. Therefore, the first condition may include that the position difference between the current position and the reference position is greater than or equal to a first threshold.

[0136] In some embodiments, a change in the terminal device's location can be associated with a change in the terminal device's signal quality. For example, if the terminal device's signal quality changes significantly, or if the difference between the signal quality of the terminal device at a first location and the signal quality of the terminal device at a second location is significant, then the position difference between the first and second locations may be significant. Therefore, the first condition may also include that the difference between the signal quality corresponding to the terminal device's current location and the signal quality corresponding to the reference location is greater than or equal to a second threshold.

[0137] The above-mentioned signal quality can be characterized by, for example, RSRP measurement results. Since the position change of the terminal device may cause the signal quality of the current serving cell to change, it may also cause the signal quality of the LTM candidate cell to change. Therefore, the above-mentioned signal quality can be determined based on the RSRP of the LTM candidate cell measured by the terminal device, and / or the RSRP of the serving cell. That is, the first condition may, for example, include that the difference between the RSRP of the serving cell corresponding to the current position of the terminal device and the RSRP of the serving cell corresponding to the reference position is greater than or equal to the second threshold; and / or the first condition may include that the difference between the RSRP of the LTM candidate cell corresponding to the current position of the terminal device and the RSRP of the LTM candidate cell corresponding to the reference position is greater than or equal to the second threshold.

[0138] Since the terminal device usually measures the signal quality, such as RSRP, during operation, the judgment of the first condition can reuse the existing signal quality measurement results, thereby helping to reduce the overhead of the terminal device.

[0139] It should be noted that the above two terminal device reference positions can be used separately or in combination, and this application does not impose any limitation on this.

[0140] In some embodiments, the aforementioned first condition is associated with the first timer, which may include associating the first condition with the first timer and the moment when the terminal device receives the TA value of the LTM candidate cell. For example, the start time of the first timer is associated with the moment when the terminal device receives the TA value of the LTM candidate cell. As an example, the first timer may be started when the terminal device receives the TA value of the LTM candidate cell.

[0141] For example, the first condition may include a first duration being greater than or equal to a timing duration of a first timer. The first duration is determined based on a time difference between the moment the terminal device receives the TA value of the LTM candidate cell and the current moment. As an example, the first duration is the time difference between the moment the terminal device receives the TA value of the LTM candidate cell and the current moment. That is, when the first timer times out, or after the timer times out, the terminal device initiates an early uplink synchronization process to the LTM candidate cell.

[0142] In some embodiments, the first condition being associated with a moving speed of the terminal device may include the first condition being associated with a moving speed of the terminal device after receiving a TA value of the LTM candidate cell.

[0143] When the terminal device is moving very slowly, or is not moving, the scene in which the terminal device is located, such as the location of the terminal device, is less likely to change; when the terminal device is moving quickly, the scene in which the terminal device is located is more likely to change. Therefore, the first condition may include that the moving speed of the terminal device after receiving the TA value of the LTM candidate cell is greater than or equal to a third threshold. The moving speed mentioned here may be the average moving speed of the terminal device or the instantaneous moving speed of the terminal device. In some embodiments, the threshold corresponding to the instantaneous moving speed of the terminal device may be greater than or equal to the threshold corresponding to the average moving speed.

[0144] As mentioned above, the first condition may be associated with the L1 measurement result of the LTM candidate cell. For example, the first condition may include that the L1 measurement result of the terminal device for the LTM candidate cell is greater than or equal to the fifth threshold. As mentioned above, the L1 measurement result of the LTM candidate cell may include the cell measurement result of the candidate cell, and may also include the beam measurement result of the candidate cell. Therefore, the first condition may include that the cell measurement result of the terminal device for the LTM candidate cell is greater than or equal to the fifth threshold, and / or the beam measurement result of the terminal device for the LTM candidate cell is greater than or equal to the fifth threshold. Among them, the beam measurement results mentioned here may include the measurement results of at least N (N is an integer greater than or equal to 1) beams, for example, N is 1. In addition, the above-mentioned L1 measurement results may, for example, include RSRP measurement results.

[0145] In some embodiments, the first condition may be pre-configured or determined based on first configuration information sent by the network device, such as an RRC configuration message. That is, in some embodiments, the network device may send first configuration information to the first terminal device, and the first configuration information may be used to determine the first condition.

[0146] In some embodiments, the first condition is associated with whether the TA value of the LTM candidate cell is known. Therefore, the first configuration information may be used to indicate whether the TA value of the LTM candidate cell is known. For example, if the first configuration information includes or indicates the TA value of the LTM candidate cell, it may indicate that the TA value of the LTM candidate cell is known. If the first configuration information does not indicate the TA value of the LTM candidate cell, it may indicate that the TA value of the LTM candidate cell is unknown. For another example, the first configuration information may include first-type configuration information and / or second-type configuration information to indicate two situations in which the TA value of the LTM candidate cell may be known.

[0147] The first type of configuration information described above can be used to indicate a TA relationship between a first cell and a second cell; wherein: the first cell and the second cell are both LTM candidate cells for the first terminal device; or, the first cell is a serving cell for the first terminal device, and the second cell is an LTM candidate cell for the first terminal device. In other words, the first type of configuration information can be used to indicate a TA relationship between an LTM candidate cell and other cells, where the other cells can be either serving cells or LTM candidate cells.

[0148] In some embodiments, the TA relationship between the first cell and the second cell may include one or more of the following: whether the first cell and the second cell belong to the same timing advance group (TAG); and the TA offset between the first cell and the second cell.

[0149] If the first cell and the second cell belong to the same TAG, the TA values ​​of the first cell and the second cell are the same. In this case, the association relationship between the first cell and the second cell can be configured to indicate this, such as using the same identifier to indicate that the first cell and the second cell belong to the same TAG group. Alternatively, the TA offset between the first cell and the second cell can be used to indicate this, such as setting the offset to 0 for flexibility.

[0150] If the first configuration information includes the configuration information of the first type, and the TA value of the first cell is known, then the TA value of the LTM candidate cell is known.

[0151] The second type of configuration information may be used to indicate that the TA value of the LTM candidate cell is 0. If the first configuration information includes the second type of configuration information, the TA value of the LTM candidate cell is known.

[0152] In an embodiment of the present application, if the TA value of the LTM candidate cell is known, the terminal device may not initiate an early uplink synchronization process with the LTM candidate cell, thereby helping to save the terminal device's overhead.

[0153] In some embodiments, if the TA value of the LTM candidate cell is unknown, such as the terminal device has not obtained the above-mentioned first type of configuration information and / or second type of configuration information, or the first configuration information does not include the above-mentioned first type of configuration information and / or second type of configuration information, then the terminal device can determine whether to initiate an early uplink synchronization process to the first LTM candidate cell based on other conditions in the first condition mentioned above.

[0154] In some embodiments, the above-mentioned first condition may be pre-configured or determined based on the first configuration information sent by the network device, such as an RRC configuration message. For example, the first configuration information may include the above-mentioned first threshold and / or second threshold. As another example, the first configuration information may include the above-mentioned first timer. Optionally, the first configuration information may include the start condition and timing duration of the above-mentioned first timer. As another example, the first configuration information may include the above-mentioned third threshold. Optionally, the first configuration information may include the type of mobility of the terminal device corresponding to the third threshold, such as the average moving speed and / or the instantaneous moving speed. As another example, the first configuration information may include the above-mentioned fifth threshold. Optionally, the first configuration information may include the type of L1 measurement result corresponding to the fifth threshold, such as the cell measurement result and / or the beam measurement result. Optionally, the first configuration information may include the parameter corresponding to the L1 measurement result corresponding to the fifth threshold, such as RSRP. As another example, the first configuration information may include the first type of configuration information and / or the second type of configuration information.

[0155] It should be noted that the various conditions described above for determining whether to initiate an early uplink synchronization process with the first LTM candidate cell by a terminal device can be used independently or in combination. For example, whether the terminal device's location change satisfies the first condition can be combined with whether the L1 measurement result of the LTM candidate cell satisfies the first condition. That is, if the terminal device's location change satisfies the first condition, it is also necessary to determine whether the L1 measurement result of the first LTM candidate cell satisfies the first condition before determining whether to initiate an early uplink synchronization process with the first LTM candidate cell. For another example, if at least one of the determinations of whether the terminal device's moving speed satisfies the first condition and whether the terminal device's location change satisfies the first condition is yes, the terminal device initiates an early uplink synchronization process with the first LTM candidate cell. For another example, if the terminal device's location change satisfies the first condition, the terminal device can also determine whether the TA value of the first LTM candidate cell is known based on the first configuration information to determine whether to initiate an early uplink synchronization process with the first LTM candidate cell.

[0156] It should be noted that the first configuration information may include one or more configuration information, that is, the multiple conditions included in the above-mentioned first condition may be determined based on the same configuration information or based on different configuration information.

[0157] In an embodiment of the present application, based on the triggering condition of early uplink synchronization (i.e., the first condition), the terminal device can initiate an early uplink synchronization process with the LTM candidate cell; thereby helping the terminal device to achieve the early uplink synchronization process with the LTM candidate cell without reporting the L1 measurement result, or when the network device does not trigger the early uplink synchronization and does not indicate the early uplink synchronization resource.

[0158] In some embodiments, multiple LTM candidate cells may meet the conditions for triggering an early uplink synchronization process, and the terminal device may select a first LTM candidate cell based on certain rules. For example, multiple LTM candidate cells of the first terminal device meet the first condition, and the first LTM candidate cell is determined from the multiple LTM candidate cells based on one or more of the following: L1 measurement results of the multiple LTM candidate cells; and whether the multiple LTM candidate cells are configured with terminal device-specific CFRA resources.

[0159] As an example, among multiple LTM candidate cells that meet the first condition, the terminal device may prioritize the candidate cell that is more likely to become the terminal device's target cell. For example, the terminal device may prioritize the candidate cell with the best L1 measurement result, or the candidate cell with a relatively good L1 measurement result. If the third and fourth cells among the LTM candidate cells both meet the first condition, and the RSRP measurement result of the fourth cell is greater than the RSRP measurement result of the third cell, the terminal device may select the fourth cell as the first LTM candidate cell.

[0160] As another example, among multiple LTM candidate cells that meet the first condition, the terminal device may give priority to the candidate cell configured with terminal device-specific CFRA resources, thereby helping to increase the probability of successful early uplink synchronization between the terminal device and the LTM candidate cell.

[0161] In some embodiments, the LTM may be a conditional LTM. That is, the first terminal device determines whether to initiate an early uplink synchronization process to the first LTM candidate cell based on a first condition, which may include the first terminal device determining whether to initiate an early uplink synchronization process to the first LTM candidate cell based on the first condition during or before executing the conditional LTM process.

[0162] In some embodiments, in addition to the first condition, the first configuration information may also include one or more of the following: at least one candidate cell configuration, a measurement configuration, and a first resource configuration.

[0163] Among them, the candidate cell configuration may include associating a candidate cell index and execution conditions with each candidate cell configuration; the measurement configuration can be used by the terminal device to perform L1 measurements related to the candidate cell, for example, the measurement configuration includes frequency configuration, synchronization signal block measurement timing configuration (SS / PBCH block measurement timing configuration, SMTC), filter coefficients, etc.; the first resource configuration may include resource configuration for early uplink synchronization process, such as downlink reference information, uplink reference signal (for example, sounding reference signal (SRS)), physical uplink control channel (physical uplink control channel, PUCCH) resources, physical uplink shared channel (physical uplink shared channel, PUSCH) resources, and random access resources.

[0164] How to achieve early uplink synchronization between the terminal device and the candidate cell may include, for example, how to determine the resources used by the terminal device to establish uplink synchronization with the candidate cell in advance. Figure 6 is a flow chart of a method for wireless communication provided by another embodiment of the present application to solve the above problem.

[0165] The method shown in Figure 6 involves a first terminal device and a network device. The method provided by the embodiment of the present application is introduced below from the perspective of the interaction between the first terminal device and the network device. The method shown in Figure 6 may include step S610.

[0166] In step S610, the first terminal device sends a random access request to the network device, or the network device receives the random access request from the first terminal device.

[0167] The random access request is used to perform uplink synchronization with the LTM candidate cell in advance. The random access request is associated with a first random access resource, or the first random access resource can be used to send the random access request. The first random access resource can be one of the following: a CFRA resource; a two-step CBRA resource; or a four-step CBRA resource.

[0168] The early uplink synchronization process between the first terminal device and the first LTM candidate cell requires the first terminal device to establish early uplink synchronization with the first LTM candidate cell while maintaining a connection to the current serving cell. In this case, the first terminal device may be unable to obtain some contention-related information, such as conflict resolution information, from the first LTM candidate cell. Based on this, the first terminal device can prioritize the use of CFRA resources for early uplink synchronization to improve the reliability of the early uplink synchronization process.

[0169] In some embodiments, if the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CFRA resource has a higher priority than the first CBRA resource. In other words, if the terminal device is configured with both a CFRA resource and a CBRA resource, the terminal device prioritizes using the CFRA resource for early uplink synchronization.

[0170] In some embodiments, if the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CBRA resource is used if the first CFRA resource is unavailable. That is, if the terminal device is configured with a CFRA resource and a CBRA resource and the CFRA resource is unavailable, the terminal device uses the CBRA resource for early uplink synchronization.

[0171] The unavailability of the first CFRA resource may, for example, refer to a poor beam measurement result of the LTM candidate cell of the first terminal device, such as a measurement result of the SSB associated with the CFRA resource being less than or equal to a preset threshold. In this case, not using the CFRA resource for early uplink synchronization helps avoid uplink synchronization failure.

[0172] In some embodiments, the first terminal device may determine whether to use CBRA resources for early uplink synchronization based on an indication from the network device. For example, the first terminal device may receive first indication information sent by the network device, where the first indication information may be used to indicate whether the first terminal device is allowed to initiate an early uplink synchronization process based on CBRA.

[0173] In some embodiments, the method shown in Figure 6 may further include step S620. In the embodiment of the present application, the terminal device may obtain resources for early uplink synchronization through a first request.

[0174] In step S620, the first terminal device sends a first request to the network device, or the network device receives the first request sent by the first terminal device.

[0175] The first request may be used to request the network device to allocate resources for an early uplink synchronization process, such as random access channel (RACH) resources or terminal device-specific CFRA resources.

[0176] In some embodiments, the first request is triggered when a second condition is not met, and the second condition is associated with one or more of the following: first resource configuration information sent by the network device; and the beam measurement result of the LTM candidate cell of the first terminal device.

[0177] In some embodiments, the second condition may include that the first resource configuration information includes resources for the first terminal device to perform an early uplink synchronization process. That is, if the first resource configuration information does not include resources for the first terminal device to perform an early uplink synchronization process, the first terminal device may send the above-mentioned first request to the network device. In some cases, the first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA to improve the reliability of the early uplink synchronization process. Therefore, the second condition may, for example, include that the first resource configuration information includes terminal device-exclusive CFRA resources. That is, if the first resource configuration information does not include terminal device-exclusive CFRA resources, the first terminal device may send the above-mentioned first request to the network device.

[0178] In some embodiments, if the first resource configuration information includes resources used by the first terminal device for early uplink synchronization, the first terminal device can determine whether to use the resources for early uplink synchronization based on the beam measurement result of the LTM candidate cell of the first terminal device, thereby helping to improve the reliability of the early uplink synchronization result. For example, the second condition may include that the first resource configuration information includes resources used by the first terminal device for early uplink synchronization, and the measurement result of one or more SSBs is greater than or equal to a fourth threshold. The one or more SSBs are associated with the resources used by the first terminal device for early uplink synchronization included in the first resource configuration information.

[0179] As described above, in some cases, the first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA. Therefore, the second condition may include, for example, that the first resource configuration information includes a terminal device-specific CFRA resource, and that the measurement results of one or more SSBs are greater than or equal to a fourth threshold. The one or more SSBs are associated with the terminal device-specific CFRA resource included in the first resource configuration information.

[0180] In some embodiments, whether the first terminal device is allowed to send the first request to the network device, or whether the first terminal device is allowed to send the first request to the network device when the second condition is not met, can be determined based on an indication of the network device. In other words, whether the first terminal device is allowed to send the first request to the network device, or whether the first terminal device is allowed to send the first request to the network device when the second condition is not met, can be determined based on an indication of the network device.

[0181] In some embodiments, the first request may include one or more of the following information: an index of the LTM candidate cell; an SSB index; indication information of a non-supplimentary uplink (NUL, i.e., normal uplink) or a supplementary uplink (SUL); measurement results of some or all beams of the LTM candidate cell; and cell measurement results of the LTM candidate cell.

[0182] In some embodiments, the network device may allocate RACH resources for early uplink synchronization to the terminal device through the PDCCH order. For example, the network device may allocate RACH resources for early uplink synchronization to the terminal device through the PDCCH order in response to the first request.

[0183] In some embodiments, if the first resource configuration information includes a terminal device-specific CFRA resource, or the first resource configuration information includes a terminal device-specific CFRA resource, and the first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA, then the first random access resource can be the terminal device-specific CFRA resource in the first resource configuration information sent by the network device.

[0184] In some embodiments, if the first resource configuration information includes a terminal device-specific CFRA resource, or the first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA, and the first resource configuration information includes a terminal device-specific CFRA resource, then the first random access resource can be a resource with better quality or better measurement results (such as the measurement results of the signal associated with the terminal device-specific CFRA resource) among the terminal device-specific CFRA resources, or the first random access resource can be any one of the terminal device-specific CFRA resources (that is, the resource can be randomly selected). For example, the above-mentioned terminal device-specific CFRA resource is associated with one or more SSBs. If the measurement result of the first SSB among the one or more SSBs is greater than or equal to the fourth threshold, the first random access resource is the terminal device-specific CFRA resource associated with the first SSB; if the measurement results of the one or more SSBs are all less than the fourth threshold, the first random access resource is the terminal device-specific CFRA resource associated with the second SSB among the one or more SSBs, and the second SSB is randomly selected by the first terminal device from the one or more SSBs.

[0185] In some cases, such as when the third condition is met, the early uplink synchronization process between the first terminal device and the LTM candidate cell is stopped. The third condition may include one or more of the following: the channel quality of the LTM candidate cell does not meet the triggering condition for the early uplink synchronization process; the CFRA resources based on the early uplink synchronization process are unavailable; there are other LTM candidate cells with L1 measurement results that are better than the LTM candidate cell; and an event that triggers random access to the serving cell is met.

[0186] The triggering condition for the above-mentioned early uplink synchronization process may be the first condition mentioned above. For example, the third condition may include that the cell measurement result and / or beam measurement result of the LTM candidate cell does not meet the fifth threshold. The cell measurement result and / or beam measurement result mentioned here may refer to the RSRP measurement result.

[0187] The CFRA resources on which the above-mentioned early uplink synchronization process is based are unavailable, which may include that the measurement results of one or more SSBs associated with the terminal device's exclusive CFRA resources are all less than the fourth threshold; or the measurement results of one or more SSBs associated with the terminal device's exclusive CFRA resources are all less than the fourth threshold and the first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA resources.

[0188] When a terminal device needs to perform a random access procedure with both the serving cell and the first LTM candidate cell, in order to ensure the communication quality of the first terminal device, the random access procedure may be performed with the serving cell first. For example, when an event triggering random access to the serving cell is met, the first terminal device preferentially initiates a random access procedure with the serving cell. In other words, the early uplink synchronization process between the first terminal device and the LTM candidate cell is stopped.

[0189] As mentioned above, the random access process may include a two-step random access process and a four-step random access process. If the first random access resource is a two-step CBRA resource, the payload of the message A sent by the first terminal device includes one or more of the following information: the cell radio network temporary identifier (C-RNTI) configured by the LTM candidate cell for the first terminal device; the identifier of the serving cell; the identifier of the serving DU; and the identifier of the serving CU. If the first random access resource is a four-step CBRA resource, the message 3 sent by the first terminal device includes one or more of the following information: the C-RNTI configured by the LTM candidate cell for the first terminal device; the identifier of the serving cell; the identifier of the serving DU; and the identifier of the serving CU.

[0190] It should be noted that the above-mentioned SSB measurement result may refer to, for example, a synchronization signal reference signal received power (SS-RSRP) measurement result (or may be referred to as the SS-RSRP measurement result of the SSB). The SS-RSRP measurement result of the SSB may refer to the average power of the synchronization signal in each resource element (RE) (or resource unit).

[0191] In an embodiment of the present application, the resources for initiating early uplink synchronization (i.e., the first random resources) can be flexibly determined based on various situations of the terminal device and the LTM candidate cell, which helps the terminal device to achieve early uplink synchronization between the terminal device and the LTM candidate cell without reporting the L1 measurement results.

[0192] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 6 . The device embodiment of the present application is described in detail below in conjunction with Figures 7 to 11 . It should be understood that the description of the method embodiment corresponds to the description of the device embodiment. Therefore, for parts not described in detail, reference can be made to the above method embodiment.

[0193] FIG7 is a schematic diagram of the structure of a terminal device provided in an embodiment of the present application. The terminal device 700 may include a determining unit 710 .

[0194] The determination unit 710 is used to determine whether to initiate an early uplink synchronization process to the first LTM candidate cell based on a first condition; wherein the first condition is associated with one or more of the following: the L1 measurement result of the LTM candidate cell; the location of the terminal device; the first timer; the moving speed of the terminal device; and whether the TA value of the LTM candidate cell is known.

[0195] In some embodiments, the first condition is associated with the location of the terminal device, including: the first condition is associated with the current location of the terminal device and / or the reference location of the terminal device.

[0196] In some embodiments, the reference location is one of the following: the location at which the terminal device receives the TA of the LTM candidate cell; and the location at which the terminal device performs LTM.

[0197] In some embodiments, the first condition includes one or more of the following: the position difference between the current position and the reference position is greater than or equal to a first threshold; and the difference between the signal quality corresponding to the current position and the signal quality corresponding to the reference position is greater than or equal to a second threshold.

[0198] In some embodiments, the signal quality is determined based on the RSRP of the LTM candidate cell and / or the RSRP of the serving cell measured by the terminal device.

[0199] In some embodiments, the first condition is associated with the first timer, including: the first condition is associated with the first timer and the moment when the terminal device receives the TA value of the LTM candidate cell.

[0200] In some embodiments, the first condition includes: a first duration is greater than or equal to the timing duration of the first timer; wherein, the first duration is determined based on the time difference between the moment when the terminal device receives the TA value of the LTM candidate cell and the current moment.

[0201] In some embodiments, the first condition is associated with the moving speed of the terminal device, including: the first condition is associated with the moving speed of the terminal device after receiving the TA value of the LTM candidate cell.

[0202] In some embodiments, the first condition includes: the moving speed or average moving speed of the terminal device after receiving the TA value of the LTM candidate cell is greater than or equal to a third threshold.

[0203] In some embodiments, the first condition is determined based on first configuration information sent by the network device.

[0204] In some embodiments, if the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes a first type of configuration information, and the first type of configuration information is used to indicate the TA relationship between the first cell and the second cell; wherein: the first cell and the second cell are both LTM candidate cells for the first terminal device; or, the first cell is the service cell of the first terminal device, and the second cell is the LTM candidate cell for the first terminal device.

[0205] In some embodiments, the TA relationship between the first cell and the second cell includes one or more of the following: whether the first cell and the second cell belong to the same TAG; and a TA offset between the first cell and the second cell.

[0206] In some embodiments, if the first configuration information includes the first type of configuration information, and the TA value of the first cell is known, then the TA value of the LTM candidate cell is known.

[0207] In some embodiments, if the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes second type of configuration information, and the second type of configuration information is used to indicate that the TA value of the LTM candidate cell is 0.

[0208] In some embodiments, the first configuration information is carried in an RRC configuration message.

[0209] In some embodiments, the multiple LTM candidate cells of the first terminal device meet the first condition, and the first LTM candidate cell is determined from the multiple LTM candidate cells based on one or more of the following: L1 measurement results of the multiple LTM candidate cells; and whether the multiple LTM candidate cells are configured with terminal device-specific CFRA resources.

[0210] In some embodiments, the first LTM candidate cell is the LTM candidate cell with the best L1 measurement result among the multiple LTM candidate cells; or, the first LTM candidate cell is the LTM candidate cell among the multiple LTM candidate cells that is configured with terminal device-specific CFRA resources.

[0211] In some embodiments, the determining unit is configured to: during a conditional LTM process, determine, according to the first condition, whether to initiate an early uplink synchronization process to the first LTM candidate cell.

[0212] FIG8 is a schematic diagram of the structure of another terminal device provided in an embodiment of the present application. The terminal device 800 may include a first sending unit 810.

[0213] The first sending unit 810 is configured to send a random access request to a network device, where the random access request is used to perform uplink synchronization with an LTM candidate cell in advance, and the random access request is associated with a first random access resource, where the first random access resource is one of the following: a CFRA resource; a two-step CBRA resource; and a four-step CBRA resource.

[0214] In some embodiments, if the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CFRA resource has a higher priority than the first CBRA resource; or, if the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CBRA resource is used if the first CFRA resource is unavailable.

[0215] In some embodiments, the device further includes: a receiving unit, configured to receive first indication information sent by the network device, where the first indication information is used to indicate whether the first terminal device is allowed to initiate an early uplink synchronization process based on CBRA.

[0216] In some embodiments, the device further includes: a second sending unit, configured to send a first request to the network device, wherein the first request is configured to request the network device to allocate RACH resources for an early uplink synchronization process or terminal device-specific CFRA resources.

[0217] In some embodiments, the first request is triggered when a second condition is not met, and the second condition is associated with one or more of the following: first resource configuration information sent by the network device; and the beam measurement result of the LTM candidate cell of the first terminal device.

[0218] In some embodiments, the second condition includes: the first resource configuration information includes a terminal device-specific CFRA resource; and

[0219] The measurement results of one or more SSBs are greater than or equal to a fourth threshold; wherein, the one or more SSBs are associated with the terminal device-specific CFRA resources included in the first resource configuration information.

[0220] In some embodiments, the first request includes one or more of the following information: an index of the LTM candidate cell; an SSB index; indication information of NUL or SUL; measurement results of some or all beams of the LTM candidate cell; and cell measurement results of the LTM candidate cell.

[0221] In some embodiments, the first random access resource is a terminal device-specific CFRA resource in the first resource configuration information sent by the network device.

[0222] In some embodiments, the first resource configuration information includes a terminal device-specific CFRA resource, the terminal device-specific CFRA resource is associated with one or more SSBs, the measurement result of a first SSB among the one or more SSBs is greater than or equal to a fourth threshold, and the first random access resource is a terminal device-specific CFRA resource associated with the first SSB; or, the first resource configuration information includes a terminal device-specific CFRA resource, the terminal device-specific CFRA resource is associated with one or more SSBs, and the measurement results of the one or more SSBs are all less than a fourth threshold, the first random access resource is a terminal device-specific CFRA resource associated with a second SSB among the one or more SSBs, and the second SSB is randomly selected by the first terminal device from the one or more SSBs.

[0223] In some embodiments, the first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA.

[0224] In some embodiments, if the third condition is met, the early uplink synchronization process between the first terminal device and the LTM candidate cell is stopped; wherein the third condition includes one or more of the following: the channel quality of the LTM candidate cell does not meet the triggering conditions of the early uplink synchronization process; the CFRA resources on which the early uplink synchronization process is based are unavailable; there are other LTM candidate cells with L1 measurement results better than the LTM candidate cell; and an event that triggers random access to the serving cell.

[0225] In some embodiments, if the first random access resource is a two-step CBRA resource, the payload of the message A sent by the first terminal device includes one or more of the following information: the C-RNTI configured for the first terminal device by the LTM candidate cell; the identifier of the serving cell; the identifier of the serving DU; and the identifier of the serving CU.

[0226] In some embodiments, if the first random access resource is a four-step CBRA resource, the message 3 sent by the first terminal device includes one or more of the following information: the C-RNTI configured for the first terminal device by the LTM candidate cell; the identifier of the serving cell; the identifier of the serving DU; and the identifier of the serving CU.

[0227] FIG9 is a schematic diagram of the structure of a network device provided in an embodiment of the present application. The network device 900 may include a sending unit 910.

[0228] The sending unit 910 is used to send first configuration information to the first terminal device, where the first configuration information is used to determine a first condition, and the first condition is used to determine whether to initiate an early uplink synchronization process to the first LTM candidate cell; wherein the first condition is associated with one or more of the following: the L1 measurement result of the LTM candidate cell; the location of the terminal device; the first timer; the moving speed of the terminal device; and whether the TA value of the LTM candidate cell is known.

[0229] In some embodiments, the first condition is associated with the location of the terminal device, including: the first condition is associated with the current location of the terminal device and / or the reference location of the terminal device.

[0230] In some embodiments, the reference location is one of the following: the location at which the terminal device receives the TA of the LTM candidate cell; and the location at which the terminal device performs LTM.

[0231] In some embodiments, the first condition includes one or more of the following: the position difference between the current position and the reference position is greater than or equal to a first threshold; and the difference between the signal quality corresponding to the current position and the signal quality corresponding to the reference position is greater than or equal to a second threshold.

[0232] In some embodiments, the signal quality is determined based on the RSRP of the LTM candidate cell and / or the RSRP of the serving cell measured by the terminal device.

[0233] In some embodiments, the first condition is associated with the first timer, including: the first condition is associated with the first timer and the moment when the terminal device receives the TA value of the LTM candidate cell.

[0234] In some embodiments, the first condition includes: a first duration is greater than or equal to the timing duration of the first timer; wherein, the first duration is determined based on the time difference between the moment when the terminal device receives the TA value of the LTM candidate cell and the current moment.

[0235] In some embodiments, the first condition is associated with the moving speed of the terminal device, including: the first condition is associated with the moving speed of the terminal device after receiving the TA value of the LTM candidate cell.

[0236] In some embodiments, the first condition includes: the moving speed or average moving speed of the terminal device after receiving the TA value of the LTM candidate cell is greater than or equal to a third threshold.

[0237] In some embodiments, if the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes a first type of configuration information, and the first type of configuration information is used to indicate the TA relationship between the first cell and the second cell; wherein: the first cell and the second cell are both LTM candidate cells for the first terminal device; or, the first cell is the service cell of the first terminal device, and the second cell is the LTM candidate cell for the first terminal device.

[0238] In some embodiments, the TA relationship between the first cell and the second cell includes one or more of the following: whether the first cell and the second cell belong to the same TAG; and a TA offset between the first cell and the second cell.

[0239] In some embodiments, if the first configuration information includes the first type of configuration information, and the TA value of the first cell is known, then the TA value of the LTM candidate cell is known.

[0240] In some embodiments, if the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes second type of configuration information, and the second type of configuration information is used to indicate that the TA value of the LTM candidate cell is 0.

[0241] In some embodiments, the first configuration information is carried in an RRC configuration message.

[0242] In some embodiments, the multiple LTM candidate cells of the first terminal device meet the first condition, and the first LTM candidate cell is determined from the multiple LTM candidate cells based on one or more of the following: L1 measurement results of the multiple LTM candidate cells; and whether the multiple LTM candidate cells are configured with terminal device-specific CFRA resources.

[0243] In some embodiments, the first LTM candidate cell is the LTM candidate cell with the best L1 measurement result among the multiple LTM candidate cells; or, the first LTM candidate cell is the LTM candidate cell among the multiple LTM candidate cells that is configured with terminal device-specific CFRA resources.

[0244] In some embodiments, the network device sends the first configuration information to the first terminal device, including: in a conditional LTM process, the network device sends the first configuration information to the first terminal device.

[0245] FIG10 is a schematic diagram of the structure of a network device provided in an embodiment of the present application. The network device 1000 may include a first receiving unit 1010 .

[0246] The first receiving unit 1010 is used to receive a random access request sent by a first terminal device, where the random access request is used to perform uplink synchronization with an LTM candidate cell in advance, and the random access request is associated with a first random access resource, where the first random access resource is one of the following: a CFRA resource; a two-step CBRA resource; and a four-step CBRA resource.

[0247] In some embodiments, if the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CFRA resource has a higher priority than the first CBRA resource; or, if the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CBRA resource is used if the first CFRA resource is unavailable.

[0248] In some embodiments, the device further includes: a sending unit, configured to send first indication information to the first terminal device, wherein the first indication information is used to indicate whether the first terminal device is allowed to initiate an early uplink synchronization process based on CBRA.

[0249] In some embodiments, the device further includes: a second receiving unit, configured to receive a first request sent by the first terminal device, wherein the first request is configured to request the network device to allocate RACH resources for an early uplink synchronization process or terminal device-specific CFRA resources.

[0250] In some embodiments, the first request is triggered when a second condition is not met, and the second condition is associated with one or more of the following: first resource configuration information sent by the network device; and the beam measurement result of the LTM candidate cell of the first terminal device.

[0251] In some embodiments, the second condition includes: the first resource configuration information includes a CFRA resource dedicated to the terminal device; and the measurement results of one or more SSBs are greater than or equal to a fourth threshold; wherein the one or more SSBs are associated with the CFRA resource included in the first resource configuration information.

[0252] In some embodiments, the first request includes one or more of the following information: an index of the LTM candidate cell; an SSB index; indication information of NUL or SUL; measurement results of some or all beams of the LTM candidate cell; and cell measurement results of the LTM candidate cell.

[0253] In some embodiments, the first random access resource is a terminal device-specific CFRA resource in the first resource configuration information sent by the network device.

[0254] In some embodiments, the first resource configuration information includes a terminal device-specific CFRA resource, the terminal device-specific CFRA resource is associated with one or more SSBs, the measurement result of a first SSB among the one or more SSBs is greater than or equal to a fourth threshold, and the first random access resource is a terminal device-specific CFRA resource associated with the first SSB; or, the first resource configuration information includes a terminal device-specific CFRA resource, the terminal device-specific CFRA resource is associated with one or more SSBs, and the measurement results of the one or more SSBs are all less than a fourth threshold, the first random access resource is a terminal device-specific CFRA resource associated with a second SSB among the one or more SSBs, and the second SSB is randomly selected by the first terminal device from the one or more SSBs.

[0255] In some embodiments, the first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA.

[0256] In some embodiments, if the third condition is met, the early uplink synchronization process between the first terminal device and the LTM candidate cell is stopped; wherein the third condition includes one or more of the following: the channel quality of the LTM candidate cell does not meet the triggering conditions of the early uplink synchronization process; the CFRA resources on which the early uplink synchronization process is based are unavailable; there are other LTM candidate cells with L1 measurement results better than the LTM candidate cell; and an event that triggers random access to the serving cell.

[0257] In some embodiments, if the first random access resource is a two-step CBRA resource, the payload of the message A sent by the first terminal device includes one or more of the following information: the C-RNTI allocated by the LTM candidate cell to the first terminal device; the identifier of the serving cell; the identifier of the serving DU; and the identifier of the serving CU.

[0258] In some embodiments, if the first random access resource is a four-step CBRA resource, the message 3 sent by the first terminal device includes one or more of the following information: the C-RNTI allocated by the LTM candidate cell to the first terminal device; the identifier of the serving cell; the identifier of the serving DU; and the identifier of the serving CU.

[0259] In an optional embodiment, the transmitting unit and receiving unit mentioned above may be the transceiver 1130. The terminal device 700, the terminal device 800, the network device 900, and the network device 1000 may further include a processor 1110 and a memory 1120, as specifically shown in FIG11 .

[0260] Figure 11 is a schematic block diagram of a communication device according to an embodiment of the present application. The dashed lines in Figure 11 indicate that the unit or module is optional. The device 1100 may be used to implement the method described in the above method embodiment. The device 1100 may be a chip, a terminal device, or a network device.

[0261] The device 1100 may include one or more processors 1110. The processor 1110 may support the device 1100 to implement the method described in the method embodiment above. The processor 1110 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0262] The apparatus 1100 may further include one or more memories 1120. The memories 1120 store programs that can be executed by the processor 1110, causing the processor 1110 to perform the methods described in the above method embodiments. The memories 1120 may be independent of the processor 1110 or integrated into the processor 1110.

[0263] The apparatus 1100 may further include a transceiver 1130. The processor 1110 may communicate with other devices or chips via the transceiver 1130. For example, the processor 1110 may transmit and receive data with other devices or chips via the transceiver 1130.

[0264] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal or network device provided in the present application, and the program enables a computer to execute the method performed by the terminal device or network device in each embodiment of the present application.

[0265] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal or network device provided in the present application, and the program causes a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0266] The present application also provides a computer program that can be applied to a terminal device or network device provided in the present application, and enables a computer to execute the method performed by the terminal device or network device in each embodiment of the present application.

[0267] It should be understood that the terms "system" and "network" in this application can be used interchangeably. In addition, the terms used in this application are only used to explain the specific embodiments of this application and are not intended to limit this application. The terms "first", "second", "third", and "fourth" in the specification and claims of this application and the accompanying drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0268] In the embodiments of this application, the term "indication" may refer to a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" may refer to a direct indication of B, e.g., B can obtain information through A; it may refer to an indirect indication of B, e.g., A indicates C, e.g., B can obtain information through C; or it may refer to an association between A and B.

[0269] In the embodiments of this application, the term "include" can refer to direct inclusion or indirect inclusion. Alternatively, the term "include" in the embodiments of this application can be replaced with "indicates" or "is used to determine." For example, "A includes B" can be replaced with "A indicates B" or "A is used to determine B."

[0270] In the embodiment of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0271] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and indication, configuration and configuration, etc.

[0272] In the embodiments of the present application, "pre-definition" or "pre-configuration" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device and a network device). The present application does not limit the specific implementation method. For example, pre-definition may refer to information defined in a protocol.

[0273] In the embodiments of the present application, the “protocol” may refer to a standard protocol in the communications field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0274] In the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0275] In various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0276] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0277] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0278] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0279] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0280] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for wireless communication, characterized in that: include: The first terminal device determines whether to initiate an early uplink synchronization process to the first layer 1 / layer 2 triggered mobility LTM candidate cell according to the first condition; The first condition is associated with one or more of the following: Layer 1 L1 measurement results of LTM candidate cells; The location of the terminal equipment; First timer; The speed at which the terminal device is moving; and Whether the timing advance TA value of the LTM candidate cell is known.

2. The method according to claim 1, characterized in that The first condition is associated with the location of the terminal device, including: the first condition is associated with the current location of the terminal device and / or the reference location of the terminal device.

3. The method according to claim 2, characterized in that The reference position is one of the following: The location of the terminal device when it receives the TA of the LTM candidate cell; and The location of the terminal device when executing LTM.

4. The method according to claim 2 or 3, characterized in that: The first condition includes one or more of the following: The position difference between the current position and the reference position is greater than or equal to a first threshold; as well as A difference between a signal quality corresponding to the current position and a signal quality corresponding to the reference position is greater than or equal to a second threshold.

5. The method according to claim 4, characterized in that The signal quality is determined based on the reference signal received power RSRP of the LTM candidate cell measured by the terminal device, and / or the RSRP of the serving cell.

6. The method according to any one of claims 1 to 5, characterized in that The first condition is associated with the first timer, including: the first condition is associated with the first timer and the moment when the terminal device receives the TA value of the LTM candidate cell.

7. The method according to claim 6, characterized in that The first condition includes: a first duration is greater than or equal to a timing duration of the first timer; wherein the first duration is determined based on a time difference between a time when the terminal device receives the TA value of the LTM candidate cell and the current time.

8. The method according to any one of claims 1 to 7, characterized in that The first condition is associated with the moving speed of the terminal device, including: the first condition is associated with the moving speed of the terminal device after receiving the TA value of the LTM candidate cell.

9. The method according to claim 8, characterized in that The first condition includes: the moving speed or average moving speed of the terminal device after receiving the TA value of the LTM candidate cell is greater than or equal to the third threshold.

10. The method according to any one of claims 1 to 9, characterized in that The first condition is determined based on first configuration information sent by the network device.

11. The method according to claim 10, characterized in that If the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes first type of configuration information, and the first type of configuration information is used to indicate a TA relationship between the first cell and the second cell; wherein: The first cell and the second cell are both LTM candidate cells of the first terminal device; or, The first cell is a serving cell of the first terminal equipment, and the second cell is an LTM candidate cell of the first terminal equipment.

12. The method according to claim 11, characterized in that The TA relationship between the first cell and the second cell includes one or more of the following: Whether the first cell and the second cell belong to the same timing advance group TAG; as well as The offset of the TA between the first cell and the second cell.

13. The method according to claim 11 or 12, characterized in that: If the first configuration information includes the first type of configuration information, and the TA value of the first cell is known, then the TA value of the LTM candidate cell is known.

14. The method according to claim 10, characterized in that If the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes second type of configuration information, and the second type of configuration information is used to indicate that the TA value of the LTM candidate cell is 0.

15. The method according to any one of claims 10 to 14, characterized in that The first configuration information is carried in a radio resource control RRC configuration message.

16. The method according to any one of claims 1 to 15, characterized in that The multiple LTM candidate cells of the first terminal device meet the first condition, and the first LTM candidate cell is determined from the multiple LTM candidate cells based on one or more of the following: L1 measurement results of the plurality of LTM candidate cells; and Whether the multiple LTM candidate cells are configured with non-contention-based random access CFRA resources exclusive to terminal devices.

17. The method according to claim 16, characterized in that: The first LTM candidate cell is the LTM candidate cell with the best L1 measurement result among the multiple LTM candidate cells; or, The first LTM candidate cell is an LTM candidate cell among the multiple LTM candidate cells that is configured with terminal device-exclusive CFRA resources.

18. The method according to any one of claims 1 to 17, characterized in that The first terminal device determines whether to initiate an early uplink synchronization process to the first LTM candidate cell according to the first condition, including: In the conditional LTM process, the first terminal device determines whether to initiate an early uplink synchronization process to the first LTM candidate cell based on the first condition.

19. A method for wireless communication, characterized in that: include: The first terminal device sends a random access request to the network device, where the random access request is used to perform uplink synchronization with a mobility LTM candidate cell triggered by layer 1 / layer 2 in advance, and the random access request is associated with a first random access resource, where the first random access resource is one of the following: Non-contention based random access to CFRA resources; Two-step contention-based random access to CBRA resources; and Four-step CBRA resources.

20. The method according to claim 19, characterized in that: If the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the priority of the first CFRA resource is higher than that of the first CBRA resource; or, If the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CBRA resource is used when the first CFRA resource is unavailable.

21. The method according to claim 19 or 20, characterized in that The method further comprises: The first terminal device receives first indication information sent by the network device, where the first indication information is used to indicate whether the first terminal device is allowed to initiate an early uplink synchronization process based on CBRA.

22. The method according to any one of claims 19 to 21, characterized in that The method further comprises: The first terminal device sends a first request to the network device, where the first request is used to request the network device to allocate a random access channel RACH resource or a terminal device-specific CFRA resource for an early uplink synchronization process.

23. The method according to claim 22, characterized in that The first request is triggered when a second condition is not satisfied, and the second condition is associated with one or more of the following: First resource configuration information sent by the network device; and The beam measurement result of the LTM candidate cell of the first terminal device.

24. The method according to claim 23, characterized in that The second condition includes: The first resource configuration information includes a terminal device-specific CFRA resource; and The measurement results of one or more synchronization signal blocks SSB are greater than or equal to a fourth threshold; wherein, the one or more SSB are associated with the terminal device-specific CFRA resources included in the first resource configuration information.

25. The method according to any one of claims 22 to 24, characterized in that The first request includes one or more of the following information: The index of the LTM candidate cell; SSB index; Indication information of a non-supplementary uplink NUL or a supplementary uplink SUL; Measurement results of some or all beams of the LTM candidate cell; as well as The cell measurement result of the LTM candidate cell.

26. The method according to any one of claims 19 to 21, characterized in that The first random access resource is a terminal device-specific CFRA resource in the first resource configuration information sent by the network device.

27. The method according to claim 26, characterized in that: The first resource configuration information includes a terminal device-specific CFRA resource, the terminal device-specific CFRA resource is associated with one or more SSBs, a measurement result of a first SSB among the one or more SSBs is greater than or equal to a fourth threshold, and the first random access resource is a terminal device-specific CFRA resource associated with the first SSB; or, The first resource configuration information includes a CFRA resource exclusive to the terminal device, the CFRA resource exclusive to the terminal device is associated with one or more SSBs, and the measurement results of the one or more SSBs are all less than a fourth threshold, and the first random access resource is a CFRA resource exclusive to the terminal device associated with the second SSB among the one or more SSBs, and the second SSB is randomly selected by the first terminal device from the one or more SSBs.

28. The method according to any one of claims 22 to 27, characterized in that The first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA.

29. The method according to any one of claims 19 to 28, characterized in that If the third condition is met, the early uplink synchronization process between the first terminal device and the LTM candidate cell is stopped; The third condition includes one or more of the following: The channel quality of the LTM candidate cell does not meet the triggering condition of the early uplink synchronization process; The CFRA resource on which the early uplink synchronization process is based is unavailable; There are other LTM candidate cells whose L1 measurement results are better than those of the LTM candidate cell; and An event that triggers random access to the serving cell is satisfied.

30. The method according to any one of claims 19 to 21, characterized in that If the first random access resource is a two-step CBRA resource, the payload of the message A sent by the first terminal device includes one or more of the following information: The LTM candidate cell is a cell radio network temporary identifier C-RNTI configured for the first terminal device; The identification of the serving cell; The identifier of the service distributed unit DU; as well as The identifier of the service center unit CU.

31. The method according to any one of claims 19 to 21, characterized in that If the first random access resource is a four-step CBRA resource, the message 3 sent by the first terminal device includes one or more of the following information: The LTM candidate cell is a C-RNTI configured for the first terminal device; The identification of the serving cell; The identity of the serving DU; and The ID of the service CU.

32. A method for wireless communication, characterized in that: include: The network device sends first configuration information to the first terminal device, where the first configuration information is used to determine a first condition, where the first condition is used to determine whether to initiate an early uplink synchronization process to a first layer 1 / layer 2 triggered mobility LTM candidate cell; The first condition is associated with one or more of the following: Layer 1 L1 measurement results of LTM candidate cells; The location of the terminal equipment; First timer; The speed at which the terminal device is moving; and Whether the timing advance TA value of the LTM candidate cell is known.

33. The method according to claim 32, characterized in that The first condition is associated with the location of the terminal device, including: the first condition is associated with the current location of the terminal device and / or the reference location of the terminal device.

34. The method according to claim 33, characterized in that The reference position is one of the following: The location of the terminal device when it receives the TA of the LTM candidate cell; and The location of the terminal device when executing LTM.

35. The method according to claim 33 or 34, characterized in that The first condition includes one or more of the following: The position difference between the current position and the reference position is greater than or equal to a first threshold; as well as A difference between a signal quality corresponding to the current position and a signal quality corresponding to the reference position is greater than or equal to a second threshold.

36. The method according to claim 35, characterized in that The signal quality is determined based on the reference signal received power RSRP of the LTM candidate cell measured by the terminal device, and / or the RSRP of the serving cell.

37. The method according to any one of claims 32 to 36, characterized in that The first condition is associated with the first timer, including: the first condition is associated with the first timer and the moment when the terminal device receives the TA value of the LTM candidate cell.

38. The method according to claim 37, characterized in that The first condition includes: a first duration is greater than or equal to a timing duration of the first timer; wherein the first duration is determined based on a time difference between a time when the terminal device receives the TA value of the LTM candidate cell and the current time.

39. The method according to any one of claims 32 to 38, characterized in that The first condition is associated with the moving speed of the terminal device, including: the first condition is associated with the moving speed of the terminal device after receiving the TA value of the LTM candidate cell.

40. The method according to claim 39, characterized in that The first condition includes: the moving speed or average moving speed of the terminal device after receiving the TA value of the LTM candidate cell is greater than or equal to the third threshold.

41. The method according to any one of claims 32 to 40, characterized in that If the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes first type of configuration information, and the first type of configuration information is used to indicate a TA relationship between the first cell and the second cell; wherein: The first cell and the second cell are both LTM candidate cells of the first terminal device; or, The first cell is a serving cell of the first terminal equipment, and the second cell is an LTM candidate cell of the first terminal equipment.

42. The method according to claim 41, characterized in that The TA relationship between the first cell and the second cell includes one or more of the following: Whether the first cell and the second cell belong to the same timing advance group TAG; as well as The offset of the TA between the first cell and the second cell.

43. The method according to claim 41 or 42, characterized in that If the first configuration information includes the first type of configuration information, and the TA value of the first cell is known, then the TA value of the LTM candidate cell is known.

44. The method according to any one of claims 32 to 43, characterized in that If the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes second type of configuration information, and the second type of configuration information is used to indicate that the TA value of the LTM candidate cell is 0.

45. The method according to any one of claims 32 to 44, characterized in that The first configuration information is carried in a radio resource control RRC configuration message.

46. ​​The method according to any one of claims 32 to 45, characterized in that The multiple LTM candidate cells of the first terminal device meet the first condition, and the first LTM candidate cell is determined from the multiple LTM candidate cells based on one or more of the following: L1 measurement results of the plurality of LTM candidate cells; and Whether the multiple LTM candidate cells are configured with non-contention-based random access CFRA resources exclusive to terminal devices.

47. The method according to claim 46, characterized in that: The first LTM candidate cell is the LTM candidate cell with the best L1 measurement result among the multiple LTM candidate cells; or, The first LTM candidate cell is an LTM candidate cell among the multiple LTM candidate cells that is configured with terminal device-exclusive CFRA resources.

48. The method according to any one of claims 32 to 47, characterized in that The network device sends first configuration information to the first terminal device, including: In the conditional LTM process, the network device sends the first configuration information to the first terminal device.

49. A method for wireless communication, characterized in that: include: The network device receives a random access request sent by the first terminal device, where the random access request is used to perform uplink synchronization with a mobility LTM candidate cell triggered by layer 1 / layer 2 in advance, and the random access request is associated with a first random access resource, where the first random access resource is one of the following: Non-contention based random access to CFRA resources; Two-step contention-based random access to CBRA resources; and Four-step CBRA resources.

50. The method according to claim 49, characterized in that: If the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the priority of the first CFRA resource is higher than that of the first CBRA resource; or, If the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CBRA resource is used when the first CFRA resource is unavailable.

51. The method according to claim 49 or 50, characterized in that The method further comprises: The network device sends first indication information to the first terminal device, where the first indication information is used to indicate whether the first terminal device is allowed to initiate an early uplink synchronization process based on CBRA.

52. The method according to any one of claims 49 to 51, characterized in that The method further comprises: The network device receives a first request sent by the first terminal device, where the first request is used to request the network device to allocate a random access channel RACH resource or a terminal device-specific CFRA resource for an early uplink synchronization process.

53. The method according to claim 52, characterized in that The first request is triggered when a second condition is not satisfied, and the second condition is associated with one or more of the following: First resource configuration information sent by the network device; and The beam measurement result of the LTM candidate cell of the first terminal device.

54. The method according to claim 53, characterized in that The second condition includes: The first resource configuration information includes a terminal device-specific CFRA resource; and The measurement results of one or more synchronization signal blocks SSB are greater than or equal to a fourth threshold; wherein the one or more SSBs are associated with the CFRA resources included in the first resource configuration information.

55. The method according to any one of claims 52 to 54, characterized in that The first request includes one or more of the following information: The index of the LTM candidate cell; SSB index; Indication information of a non-supplementary uplink NUL or a supplementary uplink SUL; Measurement results of some or all beams of the LTM candidate cell; as well as The cell measurement result of the LTM candidate cell.

56. The method according to any one of claims 49 to 51, characterized in that The first random access resource is a terminal device-specific CFRA resource in the first resource configuration information sent by the network device.

57. The method according to claim 56, characterized in that: The first resource configuration information includes a terminal device-specific CFRA resource, the terminal device-specific CFRA resource is associated with one or more SSBs, a measurement result of a first SSB among the one or more SSBs is greater than or equal to a fourth threshold, and the first random access resource is a terminal device-specific CFRA resource associated with the first SSB; or, The first resource configuration information includes a CFRA resource exclusive to the terminal device, the CFRA resource exclusive to the terminal device is associated with one or more SSBs, and the measurement results of the one or more SSBs are all less than a fourth threshold, and the first random access resource is a CFRA resource exclusive to the terminal device associated with the second SSB among the one or more SSBs, and the second SSB is randomly selected by the first terminal device from the one or more SSBs.

58. The method according to any one of claims 52 to 57, characterized in that The first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA.

59. The method according to any one of claims 49 to 58, characterized in that If the third condition is met, the early uplink synchronization process between the first terminal device and the LTM candidate cell is stopped; The third condition includes one or more of the following: The channel quality of the LTM candidate cell does not meet the triggering condition of the early uplink synchronization process; The CFRA resource on which the early uplink synchronization process is based is unavailable; There are other LTM candidate cells whose L1 measurement results are better than those of the LTM candidate cell; and An event that triggers random access to the serving cell is satisfied.

60. The method according to any one of claims 49 to 51, characterized in that If the first random access resource is a two-step CBRA resource, the payload of the message A sent by the first terminal device includes one or more of the following information: The LTM candidate cell is a cell radio network temporary identifier C-RNTI allocated to the first terminal device; The identification of the serving cell; The identifier of the service distributed unit DU; as well as The identifier of the service center unit CU.

61. The method according to any one of claims 49 to 51, characterized in that If the first random access resource is a four-step CBRA resource, the message 3 sent by the first terminal device includes one or more of the following information: The LTM candidate cell is a C-RNTI allocated by the first terminal device; The identification of the serving cell; The identity of the serving DU; and The ID of the service CU.

62. A terminal device, characterized in that: The terminal device is a first terminal device, and the terminal device includes: a determining unit, configured to determine whether to initiate an early uplink synchronization process to a first layer 1 / layer 2 triggered mobility LTM candidate cell according to a first condition; The first condition is associated with one or more of the following: Layer 1 L1 measurement results of LTM candidate cells; The location of the terminal equipment; First timer; The speed at which the terminal device is moving; and Whether the timing advance TA value of the LTM candidate cell is known.

63. The device according to claim 62, characterized in that The first condition is associated with the location of the terminal device, including: the first condition is associated with the current location of the terminal device and / or the reference location of the terminal device.

64. The device according to claim 63, characterized in that The reference position is one of the following: The location of the terminal device when it receives the TA of the LTM candidate cell; and The location of the terminal device when executing LTM.

65. Apparatus according to claim 63 or 64, characterised in that The first condition includes one or more of the following: The position difference between the current position and the reference position is greater than or equal to a first threshold; as well as A difference between a signal quality corresponding to the current position and a signal quality corresponding to the reference position is greater than or equal to a second threshold.

66. The device according to claim 65, characterized in that The signal quality is determined based on the reference signal received power RSRP of the LTM candidate cell measured by the terminal device, and / or the RSRP of the serving cell.

67. Apparatus according to any one of claims 62 to 66, characterised in that The first condition is associated with the first timer, including: the first condition is associated with the first timer and the moment when the terminal device receives the TA value of the LTM candidate cell.

68. The device according to claim 67, characterized in that The first condition includes: a first duration is greater than or equal to a timing duration of the first timer; wherein the first duration is determined based on a time difference between a time when the terminal device receives the TA value of the LTM candidate cell and the current time.

69. Apparatus according to any one of claims 62 to 68, characterised in that The first condition is associated with the moving speed of the terminal device, including: the first condition is associated with the moving speed of the terminal device after receiving the TA value of the LTM candidate cell.

70. The device according to claim 69, characterized in that The first condition includes: the moving speed or average moving speed of the terminal device after receiving the TA value of the LTM candidate cell is greater than or equal to the third threshold.

71. Apparatus according to any one of claims 62 to 70, characterised in that The first condition is determined based on first configuration information sent by the network device.

72. The device according to claim 71, characterized in that If the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes first type of configuration information, and the first type of configuration information is used to indicate a TA relationship between the first cell and the second cell; wherein: The first cell and the second cell are both LTM candidate cells of the first terminal device; or, The first cell is a serving cell of the first terminal equipment, and the second cell is an LTM candidate cell of the first terminal equipment.

73. The device according to claim 72, characterized in that The TA relationship between the first cell and the second cell includes one or more of the following: Whether the first cell and the second cell belong to the same timing advance group TAG; as well as The offset of the TA between the first cell and the second cell.

74. Apparatus according to claim 72 or 73, characterised in that If the first configuration information includes the first type of configuration information, and the TA value of the first cell is known, then the TA value of the LTM candidate cell is known.

75. The apparatus according to claim 71, characterized in that If the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes second type of configuration information, and the second type of configuration information is used to indicate that the TA value of the LTM candidate cell is 0.

76. Apparatus according to any one of claims 71 to 75, characterised in that The first configuration information is carried in a radio resource control RRC configuration message.

77. Apparatus according to any one of claims 62 to 76, characterised in that The multiple LTM candidate cells of the first terminal device meet the first condition, and the first LTM candidate cell is determined from the multiple LTM candidate cells based on one or more of the following: L1 measurement results of the plurality of LTM candidate cells; and Whether the multiple LTM candidate cells are configured with non-contention-based random access CFRA resources exclusive to terminal devices.

78. The device according to claim 77, characterized in that: The first LTM candidate cell is the LTM candidate cell with the best L1 measurement result among the multiple LTM candidate cells; or, The first LTM candidate cell is an LTM candidate cell among the multiple LTM candidate cells that is configured with terminal device-exclusive CFRA resources.

79. Apparatus according to any one of claims 62 to 78, characterised in that The determining unit is used for: In the conditional LTM process, it is determined whether to initiate an early uplink synchronization process to the first LTM candidate cell according to the first condition.

80. A terminal device, characterized in that: The terminal device is a first terminal device, and the terminal device includes: A first sending unit is configured to send a random access request to a network device, where the random access request is used to perform uplink synchronization with a mobility LTM candidate cell triggered by layer 1 / layer 2 in advance, and the random access request is associated with a first random access resource, where the first random access resource is one of the following: Non-contention based random access to CFRA resources; Two-step contention-based random access to CBRA resources; and Four-step CBRA resources.

81. The device according to claim 80, characterized in that: If the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the priority of the first CFRA resource is higher than that of the first CBRA resource; or, If the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CBRA resource is used when the first CFRA resource is unavailable.

82. The apparatus according to claim 80 or 81, characterized in that The device also includes: A receiving unit is used to receive first indication information sent by the network device, where the first indication information is used to indicate whether the first terminal device is allowed to initiate an early uplink synchronization process based on CBRA.

83. The apparatus according to any one of claims 80 to 82, characterized in that The device also includes: The second sending unit is used to send a first request to the network device, where the first request is used to request the network device to allocate random access channel RACH resources for an early uplink synchronization process or terminal device-specific CFRA resources.

84. The device according to claim 83, characterized in that The first request is triggered when a second condition is not satisfied, and the second condition is associated with one or more of the following: First resource configuration information sent by the network device; and The beam measurement result of the LTM candidate cell of the first terminal device.

85. The device according to claim 84, characterized in that The second condition includes: The first resource configuration information includes a terminal device-specific CFRA resource; and The measurement results of one or more synchronization signal blocks SSB are greater than or equal to a fourth threshold; wherein, the one or more SSB are associated with the terminal device-specific CFRA resources included in the first resource configuration information.

86. Apparatus according to any one of claims 83 to 85, characterised in that The first request includes one or more of the following information: The index of the LTM candidate cell; SSB index; Indication information of a non-supplementary uplink NUL or a supplementary uplink SUL; Measurement results of some or all beams of the LTM candidate cell; as well as The cell measurement result of the LTM candidate cell.

87. Apparatus according to any one of claims 80 to 82, characterised in that The first random access resource is a terminal device-specific CFRA resource in the first resource configuration information sent by the network device.

88. The apparatus according to claim 87, characterized in that: The first resource configuration information includes a terminal device-specific CFRA resource, the terminal device-specific CFRA resource is associated with one or more SSBs, a measurement result of a first SSB among the one or more SSBs is greater than or equal to a fourth threshold, and the first random access resource is a terminal device-specific CFRA resource associated with the first SSB; or, The first resource configuration information includes a CFRA resource exclusive to the terminal device, the CFRA resource exclusive to the terminal device is associated with one or more SSBs, and the measurement results of the one or more SSBs are all less than a fourth threshold, and the first random access resource is a CFRA resource exclusive to the terminal device associated with the second SSB among the one or more SSBs, and the second SSB is randomly selected by the first terminal device from the one or more SSBs.

89. Apparatus according to any one of claims 83 to 88, characterised in that The first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA.

90. The apparatus according to any one of claims 80 to 89, characterized in that If the third condition is met, the early uplink synchronization process between the first terminal device and the LTM candidate cell is stopped; The third condition includes one or more of the following: The channel quality of the LTM candidate cell does not meet the triggering condition of the early uplink synchronization process; The CFRA resource on which the early uplink synchronization process is based is unavailable; There are other LTM candidate cells whose L1 measurement results are better than those of the LTM candidate cell; and An event that triggers random access to the serving cell is satisfied.

91. The apparatus according to any one of claims 80 to 82, characterized in that If the first random access resource is a two-step CBRA resource, the payload of the message A sent by the first terminal device includes one or more of the following information: The LTM candidate cell is a cell radio network temporary identifier C-RNTI configured for the first terminal device; The identification of the serving cell; The identifier of the service distributed unit DU; as well as The identifier of the service center unit CU.

92. The apparatus according to any one of claims 80 to 82, characterized in that If the first random access resource is a four-step CBRA resource, the message 3 sent by the first terminal device includes one or more of the following information: The LTM candidate cell is a C-RNTI configured for the first terminal device; The identification of the serving cell; The identity of the serving DU; and The ID of the service CU.

93. A network device, characterized in that: include: A sending unit, configured to send first configuration information to a first terminal device, wherein the first configuration information is used to determine a first condition, wherein the first condition is used to determine whether to initiate an early uplink synchronization process to a first layer 1 / layer 2 triggered mobility LTM candidate cell; The first condition is associated with one or more of the following: L1 measurement results of LTM candidate cells; The location of the terminal equipment; First timer; The speed at which the terminal device is moving; and Whether the timing advance TA value of the LTM candidate cell is known.

94. The device according to claim 93, characterized in that The first condition is associated with the location of the terminal device, including: the first condition is associated with the current location of the terminal device and / or the reference location of the terminal device.

95. The device according to claim 94, characterized in that The reference position is one of the following: The location of the terminal device when it receives the TA of the LTM candidate cell; and The location of the terminal device when executing LTM.

96. The apparatus according to claim 94 or 95, characterized in that The first condition includes one or more of the following: The position difference between the current position and the reference position is greater than or equal to a first threshold; as well as A difference between a signal quality corresponding to the current position and a signal quality corresponding to the reference position is greater than or equal to a second threshold.

97. The device according to claim 96, characterized in that The signal quality is determined based on the reference signal received power RSRP of the LTM candidate cell measured by the terminal device, and / or the RSRP of the serving cell.

98. Apparatus according to any one of claims 93 to 97, characterised in that The first condition is associated with the first timer, including: the first condition is associated with the first timer and the moment when the terminal device receives the TA value of the LTM candidate cell.

99. The device according to claim 98, characterized in that The first condition includes: a first duration is greater than or equal to a timing duration of the first timer; wherein the first duration is determined based on a time difference between a time when the terminal device receives the TA value of the LTM candidate cell and the current time.

100. The apparatus according to any one of claims 93 to 99, characterized in that The first condition is associated with the moving speed of the terminal device, including: the first condition is associated with the moving speed of the terminal device after receiving the TA value of the LTM candidate cell.

101. The device according to claim 100, characterized in that The first condition includes: the moving speed or average moving speed of the terminal device after receiving the TA value of the LTM candidate cell is greater than or equal to the third threshold.

102. The apparatus according to any one of claims 93 to 101, characterized in that If the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes first type of configuration information, and the first type of configuration information is used to indicate a TA relationship between the first cell and the second cell; wherein: The first cell and the second cell are both LTM candidate cells of the first terminal device; or, The first cell is a serving cell of the first terminal equipment, and the second cell is an LTM candidate cell of the first terminal equipment.

103. The device according to claim 102, characterized in that The TA relationship between the first cell and the second cell includes one or more of the following: Whether the first cell and the second cell belong to the same timing advance group TAG; as well as The offset of the TA between the first cell and the second cell.

104. The device according to claim 102 or 103, characterized in that If the first configuration information includes the first type of configuration information, and the TA value of the first cell is known, then the TA value of the LTM candidate cell is known.

105. The apparatus according to any one of claims 93 to 104, characterized in that If the first condition is associated with whether the TA value of the LTM candidate cell is known, the first configuration information includes second type of configuration information, and the second type of configuration information is used to indicate that the TA value of the LTM candidate cell is 0.

106. The apparatus according to any one of claims 93 to 105, characterized in that The first configuration information is carried in a radio resource control RRC configuration message.

107. The apparatus according to any one of claims 93 to 106, characterized in that The multiple LTM candidate cells of the first terminal device meet the first condition, and the first LTM candidate cell is determined from the multiple LTM candidate cells based on one or more of the following: L1 measurement results of the plurality of LTM candidate cells; and Whether the multiple LTM candidate cells are configured with non-contention-based random access CFRA resources exclusive to terminal devices.

108. The device according to claim 107, characterized in that: The first LTM candidate cell is the LTM candidate cell with the best L1 measurement result among the multiple LTM candidate cells; or, The first LTM candidate cell is an LTM candidate cell among the multiple LTM candidate cells that is configured with terminal device-exclusive CFRA resources.

109. The apparatus according to any one of claims 93 to 108, characterized in that The network device sends first configuration information to the first terminal device, including: In the conditional LTM process, the network device sends the first configuration information to the first terminal device.

110. A network device, characterized in that: include: A first receiving unit is configured to receive a random access request sent by a first terminal device, where the random access request is used to perform uplink synchronization with a mobility LTM candidate cell triggered by layer 1 / layer 2 in advance, and the random access request is associated with a first random access resource, where the first random access resource is one of the following: Non-contention based random access to CFRA resources; Two-step contention-based random access to CBRA resources; and Four-step CBRA resources.

111. The device according to claim 110, characterized in that: If the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the priority of the first CFRA resource is higher than that of the first CBRA resource; or, If the network device configures a first CFRA resource and a first CBRA resource for the first terminal device, the first CBRA resource is used when the first CFRA resource is unavailable.

112. The device according to claim 110 or 111, characterized in that The device also includes: A sending unit is used to send first indication information to the first terminal device, where the first indication information is used to indicate whether the first terminal device is allowed to initiate an early uplink synchronization process based on CBRA.

113. The apparatus according to any one of claims 110 to 112, characterized in that The device also includes: The second receiving unit is used to receive a first request sent by the first terminal device, where the first request is used to request the network device to allocate random access channel RACH resources or terminal device-specific CFRA resources for an early uplink synchronization process.

114. The device according to claim 113, characterized in that The first request is triggered when a second condition is not satisfied, and the second condition is associated with one or more of the following: First resource configuration information sent by the network device; and The beam measurement result of the LTM candidate cell of the first terminal device.

115. The device according to claim 114, characterized in that The second condition includes: The first resource configuration information includes a terminal device-specific CFRA resource; and The measurement results of one or more synchronization signal blocks SSB are greater than or equal to a fourth threshold; wherein the one or more SSBs are associated with the CFRA resources included in the first resource configuration information.

116. The apparatus according to any one of claims 113 to 115, characterized in that The first request includes one or more of the following information: The index of the LTM candidate cell; SSB index; Indication information of a non-supplementary uplink NUL or a supplementary uplink SUL; Measurement results of some or all beams of the LTM candidate cell; as well as The cell measurement result of the LTM candidate cell.

117. The apparatus according to any one of claims 110 to 112, characterized in that The first random access resource is a terminal device-specific CFRA resource in the first resource configuration information sent by the network device.

118. The device according to claim 117, characterized in that: The first resource configuration information includes a terminal device-specific CFRA resource, the terminal device-specific CFRA resource is associated with one or more SSBs, a measurement result of a first SSB among the one or more SSBs is greater than or equal to a fourth threshold, and the first random access resource is a terminal device-specific CFRA resource associated with the first SSB; or, The first resource configuration information includes a terminal device-specific CFRA resource, the terminal device-specific CFRA resource is associated with one or more SSBs, and the measurement results of the one or more SSBs are all less than a fourth threshold, the first random access resource is a terminal device-specific CFRA resource associated with a second SSB in the one or more SSBs, and the second SSB is obtained by the first terminal device from the One or more SSBs are randomly selected.

119. Apparatus according to any one of claims 113 to 118, characterised in that The first terminal device is only allowed to initiate an early uplink synchronization process based on CFRA.

120. The apparatus according to any one of claims 110 to 119, characterized in that If the third condition is met, the early uplink synchronization process between the first terminal device and the LTM candidate cell is stopped; The third condition includes one or more of the following: The channel quality of the LTM candidate cell does not meet the triggering condition of the early uplink synchronization process; The CFRA resource on which the early uplink synchronization process is based is unavailable; There are other LTM candidate cells whose L1 measurement results are better than those of the LTM candidate cell; and An event that triggers random access to the serving cell is satisfied.

121. The apparatus according to any one of claims 110 to 112, characterized in that If the first random access resource is a two-step CBRA resource, the payload of the message A sent by the first terminal device includes one or more of the following information: The LTM candidate cell is a cell radio network temporary identifier C-RNTI allocated to the first terminal device; The identification of the serving cell; The identifier of the service distributed unit DU; as well as The identifier of the service center unit CU.

122. The apparatus according to any one of claims 110 to 112, characterized in that If the first random access resource is a four-step CBRA resource, the message 3 sent by the first terminal device includes one or more of the following information: The LTM candidate cell is a C-RNTI allocated by the first terminal device; The identification of the serving cell; The identity of the serving DU; and The ID of the service CU.

123. A terminal device, characterized in that: It comprises a memory and a processor, the memory is used to store a program, and the processor is used to call the program in the memory so that the terminal device executes the method as described in any one of claims 1-31.

124. A network device, characterized in that: It comprises a memory and a processor, wherein the memory is used to store a program, and the processor is used to call the program in the memory so that the network device executes the method as described in any one of claims 32-61.

125. A device, characterized in that: The device comprises a processor, configured to call a program from a memory so as to enable the device to execute the method as claimed in any one of claims 1 to 31.

126. A device, characterized in that It comprises a processor, which is used to call a program from a memory so that the device executes the method as described in any one of claims 32-61.

127. A chip, characterized in that: It comprises a processor, which is used to call a program from a memory, so that a device equipped with the chip executes a method as claimed in any one of claims 1 to 31.

128. A chip, characterized in that: It comprises a processor, which is used to call a program from a memory so that a device equipped with the chip executes a method as claimed in any one of claims 32 to 61.

129. A computer-readable storage medium, characterized in that A program is stored thereon, and the program enables a computer to execute the method according to any one of claims 1 to 31.

130. A computer-readable storage medium, characterized in that: A program is stored thereon, the program causing a computer to execute the method according to any one of claims 32-61.

131. A computer program product, characterized in that The method comprises a program which causes a computer to execute the method according to any one of claims 1 to 31.

132. A computer program product, characterized in that A program is included, which causes a computer to execute the method as claimed in any one of claims 32 to 61.

133. A computer program, characterized in that The computer program enables a computer to execute the method according to any one of claims 1 to 31.

134. A computer program, characterized in that The computer program causes a computer to execute the method according to any one of claims 32-61.

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