Timing Advance TA Determination Method and Apparatus

Abstract

This application provides a timing advance TA determination method and apparatus. The method may be applied to the communications field. The method includes the steps of: receiving a cell switch command transmitted by a serving cell; determining whether the cell switch command includes a first TA; communicating with a target cell by using the first TA if the cell switch command includes the first TA; or communicating with a target cell by using a second or third TA if the cell switch command does not include the first TA. Here, the second TA is a TA determined by a terminal device based on a reference signal of the serving cell and a reference signal of the target cell, and the third TA is a TA determined by a terminal device in a random access procedure initiated with respect to the target cell after the terminal device has received the cell switch command. When multiple TA acquisition methods coexist according to the method described above, the terminal device can correctly determine the TA for communication with the target cell in order to ensure the quality and stability of the communication performed by the terminal device.

Description

Technical Field

[0001] This application relates to the field of communications. More specifically, it relates to a timing advance (TA) determination method and apparatus. ru.

Background Art

[0002] In a mobile communication system, in order to perform normal communication, it is necessary to maintain synchronization between a terminal device and a base station. Synchronization is performed by measuring a reference signal that can be used for timing synchronization. The base station transmits the reference signal to the mobile device, and then the mobile device executes timing transmission based on the reference signal. Since signal propagation in space takes a certain amount of time and the mobile device can be located at the coverage edge of the base station, as a result, a signal transmission delay occurs. To compensate for the delay and maintain synchronization, the mobile device needs to transmit the signal before a predetermined time. Here, the advanced time can be called timing advance (TA). The terminal device can communicate with the base station at the correct moment based on the timing advance.

[0003] However, during the switching of the current cell, the terminal device needs to determine the TA for communication with the target cell in order to ensure the quality and stability of communication.

Summary of the Invention

[0004] This application provides a timing advance (TA) determination method and apparatus. When multiple TA acquisition methods coexist, the TA for communication with the target cell can be correctly determined to ensure the quality and stability of the communication executed by the terminal device.

[0005] A timing advance TA determination method is provided according to a first embodiment. The method includes the steps of: receiving a cell switch command transmitted by a serving cell; determining whether the cell switch command includes a first TA; and, if the cell switch command includes a first TA, communicating with a target cell by using the first TA, or, if the cell switch command does not include a first TA, communicating with a target cell by using a second or third TA. Here, the second TA is a TA determined by a terminal device based on a reference signal of the serving cell and a reference signal of the target cell, and the third TA is a TA determined by a terminal device in a random access procedure initiated with respect to the target cell after the terminal device has received the cell switch command.

[0006] A serving cell may be the cell currently connected to a terminal device. The terminal device can perform communication activities such as data transmission and voice calls by establishing a connection to the serving cell. A target cell may be the cell that connects to the terminal device after a cell switch and communicates with the terminal device.

[0007] Optionally, the first TA included in the cell switch command may be the value of TA, may indicate that TA is equal to 0, or may indicate that the value of TA is equal to the value of TA of the current serving cell.

[0008] Optionally, the second TA may be determined based on the downlink arrival time difference between the serving cell reference signal and the target cell reference signal.

[0009] Optionally, a random access procedure may include a race-based random access procedure or a race-free random access procedure.

[0010] In this embodiment of the present invention, after receiving a cell switch command, the terminal device can determine the TA (first TA, second TA, or third TA) for communication with the target cell by determining whether or not the cell switch command includes a first TA. In this way, when multiple TA acquisition methods coexist, the terminal device can correctly determine the TA for communication with the target cell and ensure the quality and stability of the communication performed by the terminal device.

[0011] Referring to the first aspect, in some implementations of the first aspect, before communicating with the target cell by using a first TA, the method further includes the step of determining that a first timer has not expired, the first timer being a timer that starts counting after the terminal device has sent a random access request to the target cell.

[0012] Optionally, the first timer may be configured by a network device for a terminal device.

[0013] In this embodiment of the present application, if the cell switch command includes a first TA and the first timer has not expired, the terminal device communicates with the target cell by using the first TA. In this way, if the cell switch command includes a first TA, the validity of the first TA can be further verified. This helps the terminal device correctly select the TA for communication with the target cell.

[0014] Referring to the first aspect, in some implementations of the first aspect, the second TA is acquired by a terminal device by measuring the synchronous signal block SSB of the serving cell and the SSB of the target cell at a first time point, and the step of communicating with the target cell by using the second TA or the third TA is the step of communicating with the target cell by using the second TA if the second timer has not expired, and the second timer is a timer that starts timing from the first time point.

[0015] Optionally, the terminal device may determine the second time arrival (TA) by measuring the downlink arrival time difference between the serving cell's SSB and the target cell's SSB.

[0016] Optionally, if the second timer expires, the terminal device may remeasure the serving cell's SSB and the target cell's SSB at the second time point. The second time point is later than the first time point, and the second time-attached time (TA) obtained by the terminal device is temporarily invalid before the second time point.

[0017] In this embodiment of the present application, if the cell switch command does not include the first TA and the second timer is enabled, the terminal device can communicate with the target cell by using the second TA. In this way, if the cell switch command does not include the first TA, the validity of the second TA can be further verified. This helps the terminal device correctly select the TA for communication with the target cell and ensures stable, high-quality communication between the terminal device and the target cell.

[0018] Referring to the first aspect, in some implementations of the first aspect, the step of communicating with the target cell by using a second TA or a third TA includes, if the second timer has expired, the step of communicating with the target cell by using a third TA.

[0019] In this embodiment of the present application, if the cell switch command does not include the first TA and the second timer is disabled, the terminal device can communicate with the target cell by using the third TA. In this way, loss of transmitted data caused by the terminal device incorrectly selecting a TA for communication with the target cell can be avoided.

[0020] Referring to the first aspect, in some implementations of the first aspect, the step of communicating with a target cell by using a second TA or a third TA includes the step of communicating with a target cell by using a third TA, if the random access procedure is a non-conflict random access procedure.

[0021] In this embodiment of the present application, the cell switch command does not include a first TA, and the third TA is a non-conflict random access initiated by a terminal device. procedure In the case where the TA is acquired by the terminal device, the terminal device can communicate with the target cell by using the third TA. In this way, when multiple TA acquisition methods coexist, the terminal device can correctly select the TA that needs to be used, and as a result, the terminal device can maintain efficient communication with the target cell in a variable communication environment.

[0022] Referring to the first aspect, in some implementations of the first aspect, prior to the step of receiving a cell switch command transmitted by a serving cell, the method further includes the step of transmitting capability information to the serving cell, the capability information indicating the amount of TA that a terminal device can obtain from or maintain for the target cell.

[0023] In this embodiment of the present application, a terminal device may report capability information to a serving cell before receiving a switch command transmitted by the serving cell. The capability information is associated with the terminal device's subsequent TA selection behavior, which in turn allows the terminal device to select a qualified TA, thereby ensuring the quality and stability of the communication performed by the terminal device.

[0024] According to the second aspect, a timing advance TA determination method is provided. This method includes the step of receiving a cell switch command transmitted by a serving cell, where the cell switch command includes a first TA, and the step of obtaining a third TA, where the third TA is the TA determined by the terminal device in a contention-free random access procedure started for the target cell after the terminal device receives the cell switch command, and the step of communicating with the target cell by using the third TA.

[0025] Alternatively, when the cell switch command does not include the first TA, the terminal device may communicate with the target cell by using the third TA.

[0026] In this embodiment of the present application, even when the cell switch command includes the first TA, the terminal device may communicate with the target cell by using the third TA determined in the contention-free random access procedure. In this way, when multiple TA acquisition methods coexist, the terminal device can correctly determine the TA for communication with the target cell, ensuring the quality and stability of the communication performed by the terminal device.

[0027] Referring to the second aspect, in some implementations of the second aspect, before the step of communicating with the target cell by using the third TA, this method further includes the step of determining that a first timer has expired, where the first timer is a timer that starts timing after a random access request is transmitted to the target cell.

[0028] In this embodiment of the present application, when the cell switch command includes the first TA and the first timer has expired, the terminal device can communicate with the target cell by using the third TA. In this way, the loss of transmitted data caused by communicating with the target cell by using the invalidated first TA can be avoided.

[0029] Referring to the second aspect, in some implementations of the second aspect, before the step of receiving a cell switch command transmitted by a serving cell, the method further includes a step of transmitting capability information to the serving cell, where the capability information indicates an amount of TA that the terminal device can obtain from or maintain for a target cell.

[0030] In this embodiment of the present application, before receiving a switch command transmitted by a serving cell, the terminal device may report capability information to the serving cell. The capability information is associated with the subsequent TA selection behavior of the terminal device, so that the terminal device can select a qualified TA and ensure the communication quality and stability.

[0031] According to the third aspect, a timing advance TA acquisition method is provided. The method includes steps of acquiring a second TA and a third TA, where the second TA is a TA determined by the terminal device based on a reference signal of the serving cell and a reference signal of the target cell, and the third TA is a TA determined by the terminal device in a random access procedure initiated for the target cell after the terminal device receives a cell switch command, and determining a target TA for communication with the target cell according to a preset rule.

[0032] Optionally, the preset rule may be that the priorities of the second TA and the third TA are defined. If the defined priority of the second TA is higher than the defined priority of the third TA, the target TA may be the second TA. If the defined priority of the third TA is higher than the defined priority of the second TA, the target TA may be the third TA.

[0033] Optionally, if the third TA is a TA obtained in a no-conflict random access procedure, a pre-configured rule or defined priority may be to use the third TA preferentially, i.e., the target TA is the third TA.

[0034] Optionally, if the third TA is a TA obtained through a competition-based random access procedure, a pre-configured rule or defined priority may be to preferentially use the second TA, i.e., the target TA is the second TA.

[0035] In this embodiment of the present application, when TAs acquired autonomously by a terminal device and TAs acquired in a random access procedure coexist, the TA for communication with the target cell can be determined according to a pre-configured rule. In this way, when multiple TA acquisition methods coexist, the terminal device can correctly determine the TA for communication with the target cell, ensuring the quality and stability of the communication performed by the terminal device.

[0036] A timing advance TA determination device is provided according to a fourth embodiment. The device includes a transceiver unit and a processing unit configured to receive a cell switch command transmitted by a serving cell, the processing unit being configured to determine whether the cell switch command includes a first TA, and to communicate with the target cell by using the first TA if the cell switch command includes the first TA, or by using a second or third TA if the cell switch command does not include the first TA, wherein the second TA is a TA determined by a terminal device based on a reference signal of the serving cell and a reference signal of the target cell, and the third TA is a TA determined by a terminal device in a random access procedure initiated with respect to the target cell after the terminal device has received the cell switch command.

[0037] Referring to the fourth aspect, in some implementations of the fourth aspect, the processing unit is further configured to determine that a first timer has not expired, the first timer is a timer that starts timing after a terminal device has sent a random access request to a target cell.

[0038] Referring to the fourth aspect, in some implementations of the fourth aspect, the second TA is acquired by a terminal device by measuring the synchronous signal block SSB of the serving cell and the SSB of the target cell at a first time point. The processing unit is specifically configured to communicate with the target cell by using the second TA if the second timer has not expired, the second timer being a timer that starts timing from the first time point.

[0039] Referring to the fourth aspect, in some implementations of the fourth aspect, the processing unit is specifically configured to communicate with the target cell by using the third TA when the second timer expires.

[0040] Referring to the fourth aspect, in some implementations of the fourth aspect, the processing unit is configured to communicate with the target cell by using the third TA, specifically when the random access procedure is a non-conflict random access procedure.

[0041] Referring to the fourth aspect, in some implementations of the fourth aspect, the transceiver unit is further configured to transmit capability information to the serving cell, the capability information indicating the amount of TA that the terminal device can obtain from or maintain for the target cell.

[0042] A timing advance TA determination device is provided according to a fifth embodiment. The device includes a transceiver unit configured to receive a cell switch command transmitted by a serving cell, the cell switch command including a first TA, the transceiver unit, and a processing unit configured to acquire a third TA, the third TA being a TA determined by a terminal device in a no-contradiction random access procedure initiated with respect to a target cell after the terminal device has received the cell switch command, and configured to communicate with the target cell by using the third TA.

[0043] Referring to the fifth aspect, in some implementations of the fifth aspect, the processing unit is further configured to determine that a first timer has expired, the first timer is a timer that starts timing after a random access request has been sent to a target cell.

[0044] Referring to the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is further configured to transmit capability information to the serving cell, the capability information indicating the amount of TA that the terminal device can obtain from or maintain for the target cell.

[0045] Referring to the fifth aspect, in some implementations of the fifth aspect, the device includes at least one processor and memory. The at least one processor is coupled to the memory and is configured to read and execute instructions in the memory and to cause the device to implement in a manner according to either the first or second aspect implementation.

[0046] A timing advance TA determination device is provided according to the sixth embodiment. The device includes a processing unit which acquires a second TA and a third TA, the second TA being a TA determined by a terminal device based on a reference signal of a serving cell and a reference signal of a target cell, and the third TA being a TA determined by a terminal device in a random access procedure initiated with respect to a target cell after the terminal device has received a cell switch command, and is configured to determine a target TA for communication with the target cell according to a pre-configured rule.

[0047] A timing advance TA determination device is provided according to the seventh embodiment. The device includes a processor, which is coupled to memory and configured to read and execute instructions and / or program code in memory and to perform a method according to any one of the implementations of the first to third embodiments.

[0048] A computer-readable storage medium is provided according to the eighth aspect. This computer-readable storage medium stores program code. When the computer program code is executed on the computer, the computer is made to implement one of the implementations of the first to third aspects.

[0049] A chip is provided according to the ninth aspect. The chip includes a circuit, which is configured to implement a method according to any one of the implementations of the first to third aspects.

[0050] A computer program product is provided in accordance with the tenth aspect. This computer product includes a computer program. When the computer program is executed, the computer is made to perform a method according to any one of the implementations of the first to third aspects.

[0051] A terminal device is provided that includes an apparatus in any one of the implementations of the fourth to sixth embodiments, according to the eleventh embodiment. [Brief explanation of the drawing]

[0052] [Figure 1] Figure 1 is a diagram relating to a method for obtaining uplink timing synchronization for unconnected cells by a terminal device, according to one embodiment of the present application. [Figure 2] Figure 2 is a diagram relating to acquiring TA in multiple ways by a terminal device, according to one embodiment of this application. [Figure 3] Figure 3 is a diagram relating to a system architecture to which the Timing Advance TA determination method can be applied, according to one embodiment of this application. [Figure 4] Figure 4 is a diagram illustrating an application scenario of the Timing Advance TA determination method according to one embodiment of this application. [Figure 5] Figure 5 is a schematic flowchart relating to a timing advance TA determination method according to one embodiment of this application. [Figure 6] Figure 6 is a schematic flowchart relating to a timing advance TA determination method according to one embodiment of this application. [Figure 7] Figure 7 is a schematic flowchart relating to another timing advance TA determination method according to one embodiment of this application. [Figure 8] Figure 8 is a diagram relating to a timing advance TA determination device according to one embodiment of this application. [Figure 9] Figure 9 is a diagram relating to another timing advance TA determination device according to one embodiment of this application. [Modes for carrying out the invention]

[0053] The following describes the technical solution of the embodiment of the present invention with reference to the attached drawings.

[0054] The technical solutions in the embodiments of this application can be applied to a variety of communication systems, including global systems for mobile communications (GSM), code division multiple access (CDMA) systems, wideband code division multiple access (WCDMA) systems, general packet radio service (GPRS) systems, long-term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, universal mobile telecommunications systems (UMTS), worldwide interoperability for microwave access (WiMAX) communication systems, future 5th generation (5G) systems, new radio (NR) systems, and others.

[0055] In embodiments of this application, terminal devices may be referred to as user equipment, access terminals, subscriber units, subscriber stations, mobile stations, remote stations, remote terminals, mobile devices, user terminals, terminals, wireless communication devices, user agents, user equipment, etc. Alternatively, terminal devices may include mobile phones, cordless phones, Session Initiation Protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices, other processing devices connected to wireless modems, in-vehicle devices, wearable devices, terminal devices in future 5G networks, terminal devices in future advanced public land mobile networks (PLMNs), etc. This is not limited to embodiments of this application.

[0056] The network device in the embodiments of this application may be a device configured to communicate with a terminal device. It may be a base transceiver station (BTS) in a global system for mobile communications (GSM) or code division multiple access (CDMA) system, a Node B (NB) in a wideband code division multiple access (WCDMA) system, an evolved Node B (eNB or eNodeB) in an LTE system, or a radio controller in a cloud radio access network (CRAN) scenario. Alternatively, the network device may be a relay station, an access point, an in-vehicle device, a wearable device, a network device in a future 5G network, a network device in a future evolved PLMN network, etc. This is not limited to the embodiments of this application.

[0057] To facilitate understanding of the embodiments of this application, the concepts and technologies related to the embodiments of this application will first be briefly described.

[0058] 1. Beam: A beam is a communication resource. A beam can be a broad beam, a narrow beam, or another type of beam. The technique for forming a beam can be beamforming technique or another technical means. Specifically, beamforming technique can be digital beamforming technique, analog beamforming technique, or hybrid digital / analog beamforming technique. Different beams can be considered different resources. The same or different information can be transmitted by using different beams. Optionally, multiple beams having the same or similar communication features can be considered a single beam. A single beam may include one or more antenna ports configured to perform transmissions such as data channels, control channels, and sounding signals. For example, a transmit beam may be the distribution of signal intensity formed in different directions in space after a signal has been transmitted through an antenna, and a receive beam may be the distribution of signal intensity in different directions in space of a radio signal received from an antenna. It will be understood that one or more antenna ports forming a single beam can be considered a single set of antenna ports.

[0059] When low-frequency or intermediate-frequency bands are used, signals can be transmitted in all directions or at a wide angle. When high-frequency bands are used, antenna arrays formed by multiple antenna elements may be placed at the transmitting and receiving ends due to the small carrier wavelength of high-frequency communication systems. The transmitting end transmits the signal by using specific beamforming weights, resulting in the transmitted signal forming a spatially directional beam, and the receiving end receives the signal through the antenna array by using specific beamforming weights, resulting in increased received power of the signal at the receiving end and preventing path loss.

[0060] 2. Reference Signal: Based on the Long-Term Evolution LTE / NR protocol, at the physical layer, uplink communication includes the transmission of uplink physical channels and uplink signals. Uplink physical channels include random access channels (PRACH), PUCCH, PUSCH, etc. Uplink signals include channel sounding signals (SRS), uplink control channel demodulation reference signals (PUCCH-DMRS), uplink data channel demodulation reference signals (PUSCH-DMRS), uplink phase noise tracking reference signals (PTRS), uplink positioning signals (RS), etc. Downlink communication includes the transmission of downlink physical channels and downlink signals. Downlink physical channels include broadcast channels (PBCH), physical downlink control channels (PDCCH), PDSCH, etc. The downlink signal includes the primary synchronization signal (PSS) / secondary synchronization signal (SSS), downlink control channel demodulation reference signal (PDCCH-DMRS), downlink data channel demodulation reference signal (PDSCH-DMRS), phase noise tracking signal (PTRS), channel status information reference signal (CSI-RS), cell reference signal (CRS) (not available in NR), time / frequency tracking reference signal (TRS) (not available in LTE), and LTE / NR positioning signal (positioning RS), among others.

[0061] 3. Cell switch command (CSC): The 3rd generation partnership project (3GPP) standard newly defines switch commands transmitted based on MAC CE signaling in the Rel-18 mobility subject. Messages that may be carried in the signaling include the target cell (cell group) identifier (which may be a configured logical identifier instead of a cell identifier), beam indication information (e.g., TCI status identifier), TA value, and uplink bandwidth part (BWP) identifier and / or downlink bandwidth part identifier.

[0062] The following describes the technical problems to be solved and the technical solutions in this application, with reference to the attached drawings.

[0063] In mobile communication systems, synchronization between terminal devices and base stations is necessary for normal communication. Synchronization is achieved by measuring a reference signal that can be used for timing synchronization. The base station transmits a reference signal to the mobile device, and the mobile device then performs timing transmissions based on the reference signal. Signal propagation in space takes some time, and mobile devices may be located at the base station's coverage edge, resulting in delays in signal transmission. To compensate for these delays and maintain synchronization, mobile devices need to send signals a predetermined time in advance. Here, the advanced time can be called TA. Based on the TA, the terminal device can communicate with the base station at the correct time.

[0064] To mitigate service disruptions caused by terminal devices acquiring the target cell's TA during cell switching, the 3GPP standard supports several optional solutions, including two categories: early random access channels (RACH) and non-early RACH.

[0065] The early RACH solution allows the UE to obtain the TA of the adjacent cell before the switch, and specifically includes the PDCCH directive CFRA. Details are as follows:

[0066] The serving cell distributes a PDCCH to instruct the UE to initiate a contention-free random access (CFRA) processor to the target cell. The network side does not respond with a random access response (RAR), and as a result, the UE does not need to wait for and monitor the RAR, thereby reducing interruptions. In this case, the TA is carried in the CSC.

[0067] Non-early RACH solutions can involve two branches: one where the terminal device determines the TA before the switch, and another where, after the switch, the terminal device sends a RACH to obtain the TA.

[0068] 1. The terminal device obtains the Time Attack (TA) before the cell switch. Specifically, the terminal device can calculate the TA by measuring the downlink arrival time difference between the serving cell and the target cell. In possible implementations, the terminal device may obtain the TA through a calculation according to the following formula: Target_TA=Source_TA+2RSTD+TA_NT_Adj_Factor

[0069] Target_TA may represent the TA value of the target cell that needs to be obtained by the terminal. Source_TA may be the TA used by the terminal device to transmit the uplink signal in the serving cell. RSTD may represent the arrival time difference between the downlink reference signal of the current cell (current serving cell) and the downlink reference signal of the adjacent cell, as received by the terminal device. TA_NT_Adj_Factor may represent a compensation amount that is sent by the network device to the terminal device and is used to calculate the TA. The physical meaning of TA_NT_Adj_Factor may represent the downlink transmission time difference between two cells.

[0070] 2. After a cell switch, the terminal device sends a RACH to acquire a TA. Specifically, after receiving the switch command, the terminal device acquires the TA of the new cell in the RACH procedure. This procedure cannot significantly reduce the disruption caused because the UE initiates the RACH to acquire the TA after the switch command has been delivered (the UE needs to wait for a RACH occasion for the target cell after the switch command and wait for a network response after sending the preamble. During this period, the UE is not connected to either the serving cell or the new cell). Therefore, this solution is a fallback approach.

[0071] In the following, Figure 1 is used as an example to illustrate a non-contention-based (also called contention-free) random access procedure.

[0072] As shown in Figure 1, since there is no need to resolve conflicts, gNodeB can identify which terminal device will send a random access request (i.e., information #1 in Figure 1, where information #1 includes the preamble) based on the pre-allocated preamble and RACH resource location. In addition, gNodeB can estimate the TA based on the preamble in information #1 and send information #2 to the terminal device, where information #2 includes the TA, and as a result the terminal device completes the random access procedure based on the TA. This ensures that the terminal device can communicate with gNodeB at the correct time.

[0073] However, during current cell switching, a terminal device may acquire a TA in any one or more of several ways, such as based on the serving cell's configuration or instructions. For example, in the scenario shown in Figure 2, a terminal device may acquire a TA in any one or more of the following ways: autonomously, it may acquire a TA based on the serving cell's configuration (i.e., the configuration for acquiring a TA in Figure 2), acquire a TA in the serving cell through uncontested random access (i.e., the PDCCH instruction in Figure 2), or acquire a TA based on a switch command (i.e., CSC in Figure 2, where the TA may be a TA previously acquired based on RACH triggered by PDCCH, a TA acquired by directly setting the value of the TA in the serving cell to 0, or a TA indicated by the serving cell whose value is the same as the value of the TA currently used in the serving cell). When multiple TA acquisition methods coexist, the terminal device needs to determine the TA for communication with the target cell in order to ensure the quality and stability of communication.

[0074] Embodiments of this application provide a timing advance TA determination method and apparatus. When multiple TA acquisition methods coexist, a terminal device can correctly determine the TA for communication with a target cell in order to ensure the quality and stability of the communication performed by the terminal device.

[0075] Figure 3 is a diagram relating to a system architecture to which the Timing Advance TA determination method can be applied, according to one embodiment of this application.

[0076] As shown in Figure 3, this architecture includes a terminal device 10 and a network device 20. The terminal device 10 can communicate with the network device 20. The terminal device 10 may include a processor 101, memory 102, and a transceiver 103. The transceiver 103 includes a transmitter 1031, a receiver 1032, and an antenna 1033. The network device 20 may include a processor 201, memory 202, and a transceiver 203. The transceiver 203 includes a transmitter 2031, a receiver 2032, and an antenna 2033. The receiver 1032 may be configured to receive transmission control information via the antenna 1033, and the transmitter 1031 may be configured to transmit transmission feedback information to the network device 20 via the antenna 1033. The transmitter 2031 may be configured to transmit transmission control information to the terminal device 10 via the antenna 2033, and the receiver 2032 may be configured to receive transmission feedback information transmitted by the terminal device 10 via the antenna 2033.

[0077] Figure 4 is a diagram illustrating an application scenario of the Timing Advance TA determination method according to one embodiment of this application.

[0078] As shown in Figure 4, this scenario includes a network device and a terminal device. The network device may transmit data or control commands to the terminal device. After receiving the transmitted data or control commands from the network device, the terminal device may switch its serving beam by reporting the measurement result of the reference signal (corresponding to the beam) based on the network device's configuration information. Multiple carriers are configured in each cell, and the carriers may be carrier components (CCs) in Figure 4. In the protocol, a carrier may also be called a serving cell. In addition, the scenario shown in Figure 4 is an example scenario in which a single terminal device and a single network device are used. This scenario may alternatively include multiple terminal devices and multiple network devices.

[0079] Figure 5 is a schematic flowchart relating to a timing advance TA determination method according to one embodiment of the present application. Method 500 can be applied to the system architecture shown in Figure 3 and the application scenario shown in Figure 4. Method 500 may include the following steps.

[0080] S501: The terminal device receives a cell switch command sent by the serving cell.

[0081] Optionally, the cell switch command may be a CSC. The cell switch command may or may not transport the first TA.

[0082] Optionally, the first TA included in the cell switch command is the value of TA, which may indicate that TA is equal to 0, or that the value of TA is equal to the value of the current serving cell's TA.

[0083] In one embodiment, prior to step S501, method 500 further includes the following: namely, the terminal device transmits capability information to the serving cell, where the capability information indicates the amount of TAs that the terminal device can acquire from or maintain for the target cell. The capability information may be associated with the terminal device's subsequent TA selection behavior. As a result, the terminal device can select qualified TAs to ensure the quality and stability of communication.

[0084] S502: The terminal device determines whether the cell switch command includes the first TA.

[0085] S503: The terminal device communicates with the target cell by using the first TA if the cell switch command includes the first TA, or by using the second or third TA if the cell switch command does not include the first TA.

[0086] The second TA is determined by the terminal device based on the reference signal of the serving cell and the reference signal of the target cell, and the third TA is determined by the terminal device in a random access procedure initiated on the target cell after the terminal device receives a cell switch command.

[0087] A serving cell can be the cell currently connected to a terminal device. The terminal device can perform communication activities such as data transmission and voice calls by establishing a connection to the serving cell. A target cell can be the cell that, after cell switching, connects to and communicates with the terminal device.

[0088] Optionally, the second TA may be specifically determined based on the downlink arrival time difference between the serving cell reference signal and the target cell reference signal.

[0089] Optionally, the corresponding random access procedure from which the third TA is obtained may include a competition-based random access procedure or a non-competition random access procedure.

[0090] In this embodiment of the present application, after receiving a cell switch command, the terminal device can determine the TA (first TA, second TA, or third TA) for communication with the target cell by determining whether or not the cell switch command includes a first TA. In this way, when multiple TA acquisition methods coexist, the TA for communication with the target cell can be correctly determined to ensure the quality and stability of the communication performed by the terminal device.

[0091] In one embodiment, if the cell switch command includes a first TA, the method 500 further includes the step of determining that a first timer has not expired, where the first timer is a timer that starts timing after the terminal device sends a random access request to the target cell, before the terminal device communicates with the target cell by using the first TA. In this way, if the cell switch command includes a first TA, the terminal device can further verify the validity of the first TA. This helps the terminal device correctly select a TA for communication with the target cell.

[0092] Optionally, the first timer may be a timer that starts timing from a point in time after the terminal device initiated the last random access request triggered by the PDCCH.

[0093] Optionally, the first timer may be configured by a network device for a terminal device.

[0094] Alternatively, the terminal device does not need to communicate with the target cell by using the first TA when the first timer expires.

[0095] In one embodiment, if the cell switch command does not include the first TA, and the second TA is obtained by the terminal device by measuring the serving cell's synchronization signal block (SSB) and the target cell's SSB at the first moment, the terminal device may select the second TA for communication with the target cell when the second timer has not expired. The second timer is a timer that starts counting from the first moment. In this way, if the cell switch command does not include the second TA, the terminal device can further verify the validity of the second TA. This helps the terminal device correctly select the TA for communication with the target cell and ensures stable, high-quality communication between the terminal device and the target cell.

[0096] The second timer can be understood as the time during which timing is maintained without drift after one measurement (for example, while the error requirements specified in the protocol are met). The expiration of the second timer can be understood as the point during which the second TA may no longer be accurate and is no longer applicable to data communication with the target cell after the switch.

[0097] Optionally, if the second timer expires, the terminal device may remeasure the serving cell's SSB and the target cell's SSB at the second time point. The second time point is later than the first time point, and the second time-attached time (TA) obtained by the terminal device is temporarily invalid before the second time point.

[0098] In one embodiment, if the cell switch command does not include the first TA and the second timer expires, the terminal device may select the third TA for communication with the target cell. In this way, the loss of transmitted data caused by the terminal device incorrectly selecting the TA for communication with the target cell can be avoided.

[0099] In one embodiment, if the cell switch command does not include a first TA, and the corresponding random access procedure in which the third TA is acquired is a non-conflicting random access procedure, the terminal device can communicate with the target cell by using the third TA. In this way, when multiple TA acquisition methods coexist, the terminal device can correctly select the TA that needs to be used, ensuring that the terminal device can maintain efficient communication with the target cell in a variable communication environment.

[0100] In one embodiment, if the switch command does not include a TA, the terminal device may communicate with the target cell by using a second or third TA based on a predefined priority.

[0101] Optionally, the priorities may be as follows: If a CFRA resource exists after the cell switch, the terminal device can obtain a third TA in the CFRA procedure after the cell switch and communicate with the target cell by using the third TA.

[0102] Optionally, the priorities may be as follows: If no CFRA resources exist after the cell switch, the terminal device may communicate with the target cell by obtaining a third TA in a competition-based random access procedure after the cell switch and using the second TA.

[0103] Optionally, the priorities may be as follows: If no CFRA resources exist after the cell switch, the terminal device may obtain a third TA in a competition-based random access procedure after the cell switch and communicate with the target cell by using the third TA.

[0104] Optionally, the priority may be the priority configured by the network device, or the priority configured for each cell / TAG.

[0105] Figure 6 is a schematic flowchart relating to another timing advance TA determination method according to one embodiment of the present application. Method 600 may be applied to the system architecture shown in Figure 3 and the application scenario shown in Figure 4. Method 600 may include the following steps:

[0106] S601: The terminal device receives a cell switch command sent by the serving cell.

[0107] Optionally, the cell switch command may be a CSC. And the cell switch command may carry the first TA.

[0108] Optionally, the first TA included in the cell switch command is the value of TA, which may indicate that TA is equal to 0, or that the value of TA is equal to the value of the current serving cell's TA.

[0109] In one embodiment, prior to step S601, method 600 further includes the following: namely, the terminal device transmits capability information to the serving cell, where the capability information indicates the amount of TAs that the terminal device can obtain from or maintain for the target cell. The capability information may be associated with the terminal device's subsequent TA selection behavior. As a result, the terminal device needs to determine the TAs for communication with the target cell in order to ensure the quality and stability of the communication performed by the terminal device.

[0110] S602: The terminal device acquires the 3rd TA.

[0111] The third TA is the TA determined by the terminal device in a no-contradiction random access procedure initiated against a target cell after the terminal device receives a cell switch command.

[0112] S603: The terminal device communicates with the target cell by using the third TA.

[0113] Alternatively, if the cell switch command does not include the first TA, the terminal device may communicate with the target cell by using the third TA.

[0114] In this embodiment of the present application, even when the cell switch command includes a first TA, the terminal device can communicate with the target cell by using a third TA determined in a non-conflict random access procedure. In this way, when multiple TA acquisition methods coexist, the TA for communication with the target cell can be correctly determined to ensure the quality and stability of the communication performed by the terminal device.

[0115] In one embodiment, prior to step S603, method 600 may further include the following: the terminal device determines that a first timer has expired, where the first timer is a timer that starts counting after a random access request has been sent to the target cell. In this way, the loss of transmitted data caused by the terminal device communicating with the target cell by using a disabled first TA can be avoided.

[0116] Figure 7 is a schematic flowchart relating to another timing advance TA determination method according to one embodiment of the present application. Method 700 may provide a detailed description of the steps in Methods 500 and 600. Method 700 may include the following steps:

[0117] S701: The serving cell transmits capability request information to the terminal device.

[0118] A serving cell can be a cell currently connected to a terminal device. The terminal device can perform communication activities such as data transmission and voice calls by establishing a connection to the serving cell.

[0119] S702: The terminal device transmits capability information to the serving cell.

[0120] For example, capability information is obtained when a terminal device targets a cell or is not This indicates the number of TAs that can be obtained from the serving cell or maintained for the target cell or non-serving cell.

[0121] Optionally, capability in capability information may be the number of timing advance groups (TAGs) that a terminal device can maintain for each target cell, or the number of TAs. The number of TAs may be the total number of TAs acquired by each terminal device from the target cells, the total number of TAs that a terminal device can acquire or maintain in each frequency band, or the total number of TAs that a terminal device can acquire or maintain in each frequency range (FR). The total number of TAs acquired or maintained by a terminal device in each FR may or may not include the TAs of the current serving cell.

[0122] Optionally, in method 700, steps S701 and S702 may be omitted, and step S703 may be performed directly.

[0123] S703: The serving cell transmits TA acquisition instruction information to the terminal device.

[0124] TA acquisition instruction information indicates one or more reference signals based on when a terminal device acquires the corresponding TA. TA acquisition instruction information may include an adjacent cell identifier. The adjacent cell identifier may be one or more of the following: a synchronization signal block (SSB) index, an adjacent cell channel state information reference signal (CSI-RS) resource or resource set identifier, or a measurement resource identifier for the reference signal of the associated adjacent cell.

[0125] Optionally, the TA acquisition instruction information further includes identifiers of the TAGs in the associated adjacent cells for the acquired TA.

[0126] Related adjacent cells are terminals. device After the cell switch is performed, the terminal device It should be understood that this could be the corresponding target cell.

[0127] Optionally, the TA acquisition instruction information may further include the time difference between the downlink transmission time of the target reference signal or cell and the downlink transmission time of the current serving cell. In possible implementations, only a formula may be defined in the protocol for calculating the time difference. The formula may include an offset, and the physical meaning of the offset may or may not be provided in the protocol. The offset item in the calculation method or formula provided in the protocol is optional, or the offset item may not exist. The default value of the offset may be 0 if the network device does not configure an offset for the terminal device.

[0128] Optionally, during the TA acquisition process, the terminal device may perform rate matching on the data transmission of the serving cell or set a measurement gap during measurement. Rate matching may mean that a reference signal resource to be measured exists within a contiguous time-frequency resource scheduled for the terminal device. Therefore, the data signal cannot be mapped to a resource grid where the reference signal resides. The measurement gap may be a time window set for measurement, and the terminal device does not expect to communicate with the serving cell within that time window.

[0129] In one embodiment, if the number of TAs acquired by a terminal device based on TA acquisition instruction information exceeds the maximum capacity limit of the terminal device, the terminal device releases the earliest acquired TA under the same capacity limit.

[0130] For example, a terminal device can maintain up to two Terminal Access Points (TAs). If a serving cell indicates to the terminal device that an additional TA is needed, the terminal device may release the earlier acquired TA of the two maintained TAs.

[0131] Optionally, if the protocol allows for the configuration of multiple TAs at once by using signaling, a terminal device may release a TA with a smaller index identifier. The index identifier may include an RS ID or physical cell identity (PCI). The process described above can be specifically demonstrated by using a medium access control control element (MAC CE). The MAC CE may include multiple reference signal identifiers and / or multiple corresponding cell identifiers used for TA measurement.

[0132] In one embodiment, after step S703 is performed, the terminal device does not need to acquire an amount of TA exceeding the reported capacity until it receives TA obtaining deactivation information transmitted by the serving cell.

[0133] Optionally, TA acquisition deactivation information may explicitly indicate to a terminal device that it should release or stop retaining a particular TA. A released TA is no longer permitted to be used when the terminal device subsequently performs a cell switch. In other words, in a subsequent process, if the CSC does not contain a TA, the terminal device may initiate a RACH procedure after performing a cell switch.

[0134] S704: The target cell transmits a measurement reference signal to the terminal device.

[0135] The terminal device may autonomously acquire a time-analyte (TA) based on the measurement reference signal and the serving cell reference signal. The TA autonomously acquired by the terminal device may be the second TA in method 500.

[0136] S705: The terminal device sends a response confirming successful acquisition of TA to the serving cell.

[0137] Optionally, if a TA acquired by the terminal device becomes invalid in a subsequent procedure (for example, if the specified SSB is no longer measured and as a result the TA is no longer applicable), the terminal device may report TA invalidation information to the serving cell.

[0138] S706: The serving cell sends the cell switch command CSC to the terminal device.

[0139] Optionally, the CSC may or may not transport the TA. If the CSC transports the TA, the TA may be the first TA in methods 500 and 600.

[0140] S707: The terminal device determines the TA after cell switching according to the rules.

[0141] In one embodiment, the aforementioned rule may be as follows: If the CSC includes a TA, the terminal device may determine the TA based on the CSC's instructions. The value of the TA may be obtained based on the contention-free random access-free (RAR-free) PDCCH instruction RACH procedure, by indicating that the TA is equal to 0, or by indicating that the value of the TA is equal to the value of the TA of the current serving cell. The method of obtaining the value of the TA is not limited in this embodiment of the present application.

[0142] In one embodiment, the aforementioned rule may be as follows: If the CSC does not include a TA and the target cell has a maintained TA (corresponding to the terminal device autonomously acquiring the TA), the terminal device may communicate with the target cell by using the autonomously acquired TA. When the terminal device performs communication by using the autonomously acquired TA, the serving cell can know that the terminal device has successfully autonomously acquired the TA, and the serving cell may need to explicitly indicate to the terminal device to use the TA by using the CSC.

[0143] In one embodiment, the aforementioned rule may be as follows: If the CSC does not include a TA and the terminal device does not autonomously acquire a TA, the terminal device may first perform a cell switch, and after the cell switch, the terminal device acquires a TA in the RACH procedure. The TA may be a third TA in methods 500 and 600.

[0144] Optionally, in some of the embodiments described above, if the CFRA resource is configured in RRC information transmitted to the terminal device by the serving cell, the terminal device may initiate a CFRA procedure to acquire a TA after performing a cell switch, regardless of whether the terminal device has a valid TA. The TA may be a third TA in methods 500 and 600. Alternatively, the terminal device may ignore and release the CFRA resource and use an autonomously acquired TA.

[0145] In step S707, if multiple TA acquisition methods coexist for the same target cell, the terminal device may use the TA acquired using only one of the methods.

[0146] For example, if a Terminal Address (TA) acquired autonomously by a terminal device and a TA indicated by the PDCCH directive CFRA coexist, the terminal device may abandon the autonomously acquired TA instead of using both TAs acquired by the aforementioned two methods.

[0147] In step S707, the rules that the terminal device follows may be the priority of the protocol definitions for the terminal device and the serving cell.

[0148] Optionally, the priority order may be as follows: If the CSC includes a TA, the terminal device will preferentially use the TA indicated by the CSC and ignore any TAs obtained autonomously by the terminal device.

[0149] Optionally, the priority order may be as follows: if a CFRA resource exists after a cell switch, the terminal device may first perform a cell switch, and then, after the switch, initiate a CFRA procedure to obtain a TA, and then ignore any TAs obtained autonomously by the terminal device.

[0150] Optionally, the priority order may be as follows: If the CSC includes a TA and a CFRA resource exists after the cell switch, the terminal device will use the autonomously acquired TA.

[0151] Optionally, the priority order may be as follows: If the terminal device can autonomously acquire a TA and a CFRA resource exists after the cell switch, the terminal device will use the TA acquired by the CFRA procedure initiated after the cell switch.

[0152] Optionally, the priority order may be as follows: If the terminal device can autonomously acquire a TA and no CFRA resources exist after the cell switch, the terminal device will use the TA acquired in the RACH procedure after the cell switch.

[0153] Optionally, the priority order may be as follows: If the terminal device can autonomously acquire a TA and no CFRA resources exist after the cell switch, the terminal device will use the autonomously acquired TA.

[0154] Optionally, the priority may be the priority configured by the network device, or the priority configured for each cell / TAG.

[0155] If, prior to step S706, the serving cell configures a first timer for a terminal device, then in step S707, the terminal device may determine the TA to be used after the cell switch by referring to the timeout status and rules of the first timer.

[0156] In one embodiment, if a terminal device autonomously acquires a Target Audience (TA) for a target cell, after receiving a DCI, the terminal device may send a random access request to the target cell. The random access request indicates that a CFRA (Call for Response) is sent to the terminal device. The first timer begins timing from the point after the terminal device initiated the last random access request. (Since random access requests sent by the terminal device at one time may not be received by the target cell, the terminal device may send multiple random access requests to the same target cell.)

[0157] In one embodiment, if the CSC transmitted by the serving cell to the terminal device includes a TA, and the first timer has not expired, the terminal device may use the TA indicated by the CSC as the TA after the cell switch. In other words, the priority of the TA indicated by the CSC is higher than the priority of the TA autonomously acquired by the terminal device.

[0158] In one embodiment, if the CSC transmitted by the serving cell to the terminal device includes a TA, and the first timer expires, the terminal device may use the autonomously acquired TA as the TA after the cell switch.

[0159] In one embodiment, if a CSC sent by a serving cell to a terminal device includes a TA, and the first timer expires and the terminal device does not (or cannot) autonomously acquire the TA, the terminal device may initiate a RACH procedure to acquire the TA after the cell switch. In other words, the terminal device may ignore the TA included in the CSC in this case.

[0160] In step S703, if the TA autonomously acquired by the terminal device is acquired through a single measurement, specifically, the terminal device performs a measurement calculation once based on the SSB of the adjacent cell (target cell), rather than a periodic measurement, and the terminal device may acquire a second timer. Here, the second timer represents the validity period of the TA acquired after the terminal device has performed a single measurement.

[0161] Optionally, the second timer is, The second timer can be understood as the time during which the timing remains drift-free after the terminal device has performed a measurement once. The drift-free time can be understood as the time during which the error specified in the protocol is satisfied. The expiration of the second timer can be understood as the TA obtained by the terminal device being inaccurate and the TA being unapplicable to communication between the terminal device and the target cell after the cell switch.

[0162] Optionally, after the second timer expires, the terminal device may wait until the next cycle of the adjacent cell's SSB to perform a remeasurement. Before the remeasurement, the TA is temporarily disabled.

[0163] Optionally, if a terminal device is unable to perform data transmission in a serving cell when measuring a Time Attunement (TA), the terminal device may determine, based on the timer and the position of the periodic SSB in adjacent cells, which time-domain resources need to be punctured for measurement. In this way, the terminal device can avoid interference with data transmission in the serving cell while ensuring synchronization between the terminal device and the serving cell.

[0164] The above describes the timing advance TA determination method provided in the embodiments of this application. Below, with reference to Figures 8 and 9, the apparatus and devices according to the embodiments of this application will be described.

[0165] Figure 8 is a diagram relating to a Timing Advance TA determination device 800 according to one embodiment of the present application. The device 800 may include a transceiver unit 810, a storage unit 820, and a processing unit 830. The transceiver unit 810 is configured to receive and transmit commands and / or data. The transceiver unit 810 may also be called a communication interface or communication unit. The storage unit 820 implements corresponding storage functions and is configured to store corresponding commands and / or data. The processing unit 830 can read commands and / or data from the storage unit and cause the device 800 to perform the Timing Advance TA determination method described above.

[0166] In one design, the device 800 includes: a transceiver unit 810 configured to receive cell switch commands transmitted by a serving cell; and a processing unit 830 configured to determine whether the cell switch command includes a first TA, and if so, to communicate with the target cell by using the first TA, or if so, to communicate with the target cell by using a second or third TA. Here, the second TA is a TA determined by the terminal device based on the reference signals of the serving cell and the target cell, and the third TA is a TA determined by the terminal device in a random access procedure initiated with respect to the target cell after the terminal device has received the cell switch command.

[0167] In possible implementations, the processing unit 830 is further configured to determine that the first timer has not expired, where the first timer is a timer that starts counting after the terminal device has sent a random access request to the target cell.

[0168] In possible implementations, the second time agent (TA) is acquired by a terminal device by measuring the synchronous signal block (SSB) of the serving cell and the SSB of the target cell at the first time point. The processing unit 830 is specifically configured to communicate with the target cell by using the second time agent if the second timer has not expired. Here, the second timer is a timer that starts timing from the first time point.

[0169] In possible implementations, the processing unit 830 is specifically configured to communicate with the target cell by using the third TA when the second timer expires.

[0170] In possible implementations, the processing unit 830 is specifically configured to communicate with the target cell by using a third TA when the random access procedure is a non-conflict random access procedure.

[0171] In possible implementations, the transceiver unit 810 is further configured to transmit capability information to the serving cell, where the capability information indicates the number of TAs that the terminal device can acquire from or maintain for the target cell.

[0172] In one design, the device 800 includes: a transceiver unit 810 configured to receive a cell switch command transmitted by a serving cell, where the cell switch command includes a first TA; and a processing unit 83 configured to acquire a third TA, where the third TA is determined by a terminal device in a no-contradiction random access procedure initiated with respect to a target cell after the terminal device has received the cell switch command, and to communicate with the target cell by using the third TA.

[0173] In possible implementations, the processing unit 830 is further configured to determine when a first timer has expired, where the first timer is a timer that starts counting after a random access request has been sent to the target cell.

[0174] In possible implementations, the transceiver unit 810 is further configured to transmit capability information to the serving cell, where the capability information indicates the number of TAs that the terminal device can acquire from or maintain for the target cell.

[0175] In one design, the device 800 is configured to acquire a second TA and a third TA, where the second TA is determined by a terminal device based on a reference signal of a serving cell and a reference signal of a target cell, and the third TA is determined by a terminal device in a random access procedure initiated to the target cell after the terminal device has received a cell switch command, and includes a processing unit 830 configured to determine a target TA for communication with the target cell according to pre-configured rules.

[0176] Figure 9 is a diagram relating to another timing advance TA determination device 900 according to one embodiment of this application.

[0177] The device 900 includes a memory 910, a processor 920, and a communication interface 930. The memory 910, processor 920, and communication interface 930 are connected via an internal connection path. The memory 910 is configured to store instructions. The processor 920 is configured to execute instructions stored in the memory 910, control the communication interface 930 to obtain information, and cause the device 900 to implement the timing advance TA determination method described above. Optionally, the memory 910 may be coupled to the processor 920 via an interface, or may be integrated with the processor 920.

[0178] It should be noted that the communication interface 930 uses transceiver equipment, for example, but is not limited to these transceivers. The communication interface 930 may further include an input / output interface.

[0179] The processor 920 stores one or more computer programs, each of which contains instructions. When an instruction is executed by the processor 920, the device 900 is configured to perform the timing advance TA determination method described in the above-described embodiment.

[0180] It should be understood that the processor in the embodiments of this application may be a central processing unit (CPU), or may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or another 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.

[0181] In embodiments of the present application, it should also be understood that the memory includes read-only memory and random-access memory, and that it may provide instructions and data to the processor. A portion of the processor may further include non-volatile random-access memory. For example, the processor may further store information about the device type.

[0182] In the implementation process, the steps relating to the method described above may be implemented by using hardware integrated logic circuits in the processor 920 or by using instructions in the form of software. The method disclosed with reference to embodiments of this application may be performed and completed directly by a hardware processor or by using a combination of hardware and software modules in the processor. The software modules may be located in mature storage media in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. The storage medium is located in memory 910, and the processor 920 reads information in memory 910 and, in combination with the processor hardware, completes the steps of the method described above. To avoid repetition, details are not described again here.

[0183] Optionally, the communication interface 930 in Figure 9 may implement the transceiver unit 810 in Figure 8, the memory 910 in Figure 9 may implement the storage unit 820 in Figure 8, and the processor 920 in Figure 9 may implement the processing unit 830 in Figure 8.

[0184] One embodiment of this application further provides a computer-readable storage medium that stores program code. When the computer program code is executed on a computer, the computer is made to perform one of the methods shown in Figures 5 to 7.

[0185] One embodiment of this application further provides a computer program product. The computer product includes a computer program. When the computer program is executed, the computer is made to perform one of the methods shown in Figures 5 to 7.

[0186] One embodiment of this application further provides a chip including a circuit, the circuit configured to implement one of the methods shown in Figures 5 to 7.

[0187] One embodiment of this application further provides a terminal device including an arbitrary timing advance determination device, as shown in Figure 8 or Figure 9.

[0188] Those skilled in the art will recognize, in combination with the examples described in the embodiments disclosed herein, that the units and algorithmic steps can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether the functions are performed by hardware or by software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0189] Those skilled in the art will clearly understand that, for the sake of convenience and concise explanation, the detailed operating processes of the aforementioned systems, apparatus, and units can be clearly described by referring to the corresponding processes in the embodiments of the methods described above. Further details are not described here.

[0190] It should be understood that in some embodiments provided in this application, the disclosed systems, apparatus, and methods may be implemented in other ways. For example, the embodiments of the apparatus described are merely examples. For example, the division into units is merely a logical functional division. In actual implementation, other division methods may exist. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the mutual coupling, direct coupling, or communication connection shown or described may be implemented through some interfaces. Indirect coupling or communication connection between apparatus or units may be implemented electronically, mechanically, or in other forms.

[0191] Units described as separate parts may or may not be physically separate. And parts shown as units may or may not be physical units, may be located in one location, or may be distributed across multiple network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solution of the embodiment.

[0192] In addition, the functional units in the embodiments of this application may be integrated into a single processing unit, each unit may exist physically independently, or two or more units may be integrated into a single unit.

[0193] If a function is implemented in the form of a software function unit and sold or used as an independent product, the function may be stored on a computer-readable storage medium. Based on this understanding, the technical solution of this application, or a portion of the technical solution, may be implemented in the form of a software product. The computer software product is stored on a storage medium and contains several instructions for instructing a computer device (which may be a personal computer, server, network device, etc.) to perform all or part of the steps of the method described in the embodiments of this application. The aforementioned storage medium includes any medium capable of storing program code, such as a USB flash drive, removable hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0194] The foregoing description is merely a specific example of the present application, but is not intended to limit the scope of protection of the present application. Any modifications or substitutions readily conceivable by a person skilled in the art within the scope of the art disclosed herein shall fall within the scope of protection of the present application. Accordingly, the scope of protection of the present application is subject to the scope of protection of the claims.

Claims

1. This is a timing advance TA determination method, The steps include receiving a cell switch command sent by a serving cell, The steps include determining whether the cell switch command includes the first TA, If the cell switch command includes the first TA, the step of communicating with the target cell by using the first TA, If the cell switch command does not include the first TA, the step of communicating with the target cell by using the second TA or the third TA, Includes, The second TA is a TA determined by the terminal device based on the reference signal of the serving cell and the reference signal of the target cell, and The third TA is a TA determined by the terminal device in a random access procedure initiated for the target cell after the terminal device receives the cell switch command. method.

2. Before the step of communicating with the target cell by using the first TA, the method further: A step of determining that the first timer has not expired, wherein the first timer is a timer that starts counting after the terminal device sends a random access request to the target cell, The method according to claim 1, including the method described in claim 1.

3. The second TA is acquired by the terminal device by measuring the synchronization signal block SSB of the serving cell and the SSB of the target cell at the first time point, and The step of communicating with the target cell by using the second TA or the third TA is: If the second timer has not expired, the second TA is used to communicate with the target cell. The second timer is a timer that starts timing from the first time point, step, The method according to claim 1, including the method described in claim 1.

4. The step of communicating with the target cell by using the second TA or the third TA is: When the second timer expires, the third TA is used to communicate with the target cell. The method according to claim 3, including the method described in claim 3.

5. The step of communicating with the target cell by using the second TA or the third TA is: If the aforementioned random access procedure is a non-conflicting random access procedure, the third TA is used to communicate with the target cell. The method according to claim 1, including the method described in claim 1.

6. Prior to the step of receiving the cell switch command transmitted by the serving cell, the method further: The step is to transmit capability information to the serving cell, The capability information indicates the amount of TA that the terminal device can acquire from or maintain for the target cell, step, The method according to any one of claims 1 to 5, including

7. The above method further, This is a step of receiving configuration information sent by a network device. The configuration information provides instructions to the terminal device to autonomously acquire the second TA based on the configuration of the serving cell, and the steps include: The steps include determining the second TA based on the configuration information, The method according to any one of claims 1 to 6, including

8. This is a timing advance TA determination method, This is a step of receiving a cell switch command sent by a serving cell. The cell switch command includes a step, which includes a first TA. This is the step to obtaining the 3rd TA. The third TA is a TA determined by the terminal device in a no-contradiction random access procedure initiated for a target cell after the terminal device receives the cell switch command, step The steps include: using the third TA to communicate with the target cell, Methods that include...

9. Before the step of communicating with the target cell by using the third TA, the method further: This is the step where it is determined that the first timer has expired. The first timer is a timer that starts counting after a random access request is sent to the target cell, step, The method according to claim 8, including the method described in claim 8.

10. Prior to the step of receiving the cell switch command transmitted by the serving cell, the method further: The step is to transmit capability information to the serving cell, The capability information indicates the amount of TA that the terminal device can acquire from or maintain for the target cell, step, The method according to claim 8 or 9, including the method described in claim 8 or 9.

11. A timing advance TA determination device A transceiver unit configured to receive cell switch commands transmitted by a serving cell, and Including a processing unit, The aforementioned processing unit is Determine whether the cell switch command includes the first TA, When the cell switch command includes the first TA, the first TA is used to communicate with the target cell, or If the cell switch command does not include the first TA, communication with the target cell is performed by using the second TA or the third TA. It is configured in such a way, The second TA is a TA determined by the terminal device based on the reference signal of the serving cell and the reference signal of the target cell, and The third TA is a TA determined by the terminal device in a random access procedure initiated for the target cell after the terminal device receives the cell switch command. Device.

12. The aforementioned processing unit further, It is configured to determine that the first timer has not expired. The first timer is a timer that starts counting after the terminal device sends a random access request to the target cell. The apparatus according to claim 11.

13. The second TA is acquired by the terminal device by measuring the synchronization signal block SSB of the serving cell and the SSB of the target cell at the first time point, and The processing unit, specifically, The system is configured to communicate with the target cell by using the second TA when the second timer has not expired. The second timer is a timer that starts timing from the first time point. The apparatus according to claim 11.

14. The processing unit, specifically, When the second timer expires, the system is configured to communicate with the target cell by using the third TA. The apparatus according to claim 13.

15. The processing unit, specifically, When the aforementioned random access procedure is a non-conflicting random access procedure, the third TA is configured to communicate with the target cell. The apparatus according to claim 11.

16. The transceiver unit is further configured to transmit capability information to the serving cell. The capability information indicates the amount of TA that the terminal device can acquire from or maintain for the target cell. The apparatus according to any one of claims 11 to 15.

17. The transceiver unit is further configured to receive configuration information transmitted by a network device. The configuration information instructs the terminal device to autonomously acquire the second TA based on the configuration of the serving cell, and The processing unit is further configured to determine the second TA based on the configuration information. The apparatus according to any one of claims 11 to 16.

18. A timing advance TA determination device, A transceiver unit configured to receive cell switch commands transmitted by a serving cell, wherein the cell switch commands include a first TA, and Including a processing unit, The aforementioned processing unit is The system is configured to acquire a third TA, the third TA being a TA determined by the terminal device in a no-contradiction random access procedure initiated for the target cell after the terminal device receives the cell switch command, and The third TA is configured to communicate with the target cell, Device.

19. The aforementioned processing unit further, It is configured to determine when the first timer has expired. The first timer is a timer that starts counting after a random access request is sent to the target cell. The apparatus according to claim 18.

20. The aforementioned transceiver unit further, It is configured to transmit capability information to the serving cell, The capability information indicates the amount of TA that the terminal device can acquire from or maintain for the target cell. The apparatus according to claim 18 or 19.

21. A timing advance TA determination device including a processor and memory, The aforementioned processor, The memory is coupled to the aforementioned memory, and The system is configured to read and execute instructions in the memory and to carry out the method described in any one of claims 1 to 7. Device.

22. A timing advance TA determination device including a processor and memory, The aforementioned processor, The memory is coupled to the aforementioned memory, and The system is configured to read and execute instructions in the memory and to carry out the method described in any one of claims 8 to 10. Device.

23. A computer-readable storage medium, The computer-readable storage medium stores program code, and When the computer program code is executed on the computer, the computer is configured to carry out the method according to any one of claims 1 to 10. Computer-readable storage medium.

24. A chip equipped with a circuit, The circuit is configured to carry out the method described in any one of claims 1 to 10. Tip.

25. A terminal device comprising the apparatus described in any one of claims 11 to 22.

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