Timing advance management method, device, storage medium, and product

Abstract

The embodiments of the present application relate to the technical field of communications. Provided are a timing advance management method, a device, a storage medium, and a product. The method comprises: receiving first indication information sent by a first network device, wherein the first indication information is used for indicating a device for performing validity management on a timing advance (TA) of a candidate cell, the device for performing validity management on the timing advance (TA) of the candidate cell is a terminal device or the first network device or a second network device, and there is one or more candidate cells; and if the device for performing validity management on the TA of the candidate cell is the terminal device, performing validity management on the TA of the candidate cell on the basis of the first indication information. Therefore, validity management is selectively performed on a TA by means of a terminal device or a first network device or a second network device, thereby improving the flexibility of TA management.

Description

Timing advance management method, device, storage medium and product

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on February 8, 2024, with application number 202410175844.3 and application name “Timing Advance Management Method, Device, Storage Medium and Product”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a timing advance management method, device, storage medium, and product. Background Art

[0003] With the continuous development of communication technologies, various mobility management methods have emerged. One such mobility management mechanism is the Layer 1 / 2 triggered mobility (LTM) mechanism. In the LTM mechanism, before triggering a cell change, to ensure uplink synchronization between the terminal and the candidate cell, the terminal is triggered to obtain the timing advance of the candidate cell and needs to manage the validity of the timing advance (TA).

[0004] Currently, the effectiveness of TA is generally managed by network devices, resulting in poor flexibility in TA management. Summary of the Invention

[0005] The embodiments of the present application provide a timing advance management method, device, storage medium, and product, which are applied to the field of communication technology, so as to selectively manage the effectiveness of TA through terminal equipment, source cell network equipment, or candidate cell network equipment when managing the effectiveness of TA, thereby improving the flexibility of TA management.

[0006] In a first aspect, embodiments of the present application provide a timing advance management method, which may be executed by a terminal device, or may be executed by a component (eg, a chip or circuit) configured in the terminal device, but is not limited in this application.

[0007] For example, the method includes: receiving first indication information sent by a first network device, the first indication information being used to indicate a device for managing the validity of a timing advance (TA) of a candidate cell; the device for managing the validity of a timing advance (TA) of a candidate cell being a terminal device, a first network device, or a second network device; there being one or more candidate cells; and if the device for managing the validity of a TA of a candidate cell is a terminal device, managing the validity of the TA of the candidate cell according to the first indication information. The first network device is a source cell network device, and the second network device is a candidate cell network device.

[0008] Therefore, the timing advance management method provided in the embodiments of the present application provides three methods for managing the validity of the TA of one or more candidate cells, namely, managing the validity of the TA based on the terminal device, the first network device, or the second network device. Therefore, the terminal device manages the validity of the TA of the candidate cell by receiving the first indication information sent by the first network device and determining that the first indication information indicates that the terminal device is responsible for managing the validity of the TA. This improves the flexibility of TA management by not being limited to management by only the network device.

[0009] Optionally, the method further includes: receiving second indication information sent by the first network device, the second indication information being used to indicate whether the contention-free random access CFRA process includes a random access response RAR; sending a CFRA request to the second network device, the CFRA request being used to instruct the second network device to obtain a TA of the corresponding candidate cell; if the second indication information indicates that the CFRA process includes the RAR, receiving the RAR sent by the second network device, the RAR including the TA of the corresponding candidate cell;

[0010] or;

[0011] A CFRA request including an RAR is sent to the second network device, where the CFRA request including the RAR is used to indicate that the CFRA process includes the RAR; and the RAR sent by the second network device is received, where the RAR includes a TA corresponding to the candidate cell.

[0012] That is to say, the premise of managing the validity of TA is that the terminal device must first obtain TA. Two methods are provided here to enable the terminal device to obtain TA. The first method is that the terminal device receives the second indication information for indicating whether the CFRA process includes RAR, and sends a CFRA request to the second network device according to the second indication information, so that when the second indication information indicates that the CFRA process includes RAR, the terminal device receives the RAR including the corresponding candidate cell TA sent by the second network device, thereby enabling the terminal device to use RAR to successfully obtain the TA returned by the second network device, compared to sending a new instruction to obtain TA, saving transmission resources. The second method is that the terminal device sends a CFRA request including RAR to the second network device by itself, thereby receiving the RAR including the corresponding candidate cell TA sent by the second network device, thereby enabling the terminal device to send a CFRA request including RAR by itself, thereby improving the efficiency of obtaining the candidate cell TA.

[0013] On this basis, the present application provides two methods for the terminal device to obtain the TA of the candidate cell, thereby increasing the flexibility of the terminal device in obtaining the TA.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the carrying manner of the first indication information and the second indication information may be: the first indication information and the second indication information are carried in a physical downlink control channel scheduling PDCCH instruction; or, the first indication information and the second indication information are carried in an unlimited resource control RRC reconfiguration signaling message; or, the first indication information is carried in the PDCCH instruction and the second indication information is carried in the RRC reconfiguration signaling message; or, the first indication information is carried in the RRC reconfiguration signaling message and the second indication information is carried in the PDCCH instruction.

[0015] That is, four modes of carrying the first indication information and the second indication information are provided, thereby improving the flexibility of transmitting the first indication information and the second indication information. Furthermore, by carrying the first indication information and the second indication information in a PDCCH instruction or an RRC reconfiguration signaling message, or by carrying the first indication information in a PDCCH instruction and the second indication information in an RRC reconfiguration signaling message, or by carrying the first indication information in an RRC reconfiguration signaling message and the second indication information in a PDCCH instruction, waste of resources caused by additional transmission can be avoided.

[0016] On this basis, the present application provides four methods for carrying the first indication information and the second indication information to improve the flexibility of transmitting the first indication information and the second indication information.

[0017] It should be understood that the PDCCH instruction may also carry CFRA resources used by the terminal device to initiate the CFRA process. The RRC reconfiguration signaling message may also carry candidate cell configuration information.

[0018] Optionally, the method further includes: receiving first configuration information and second configuration information sent by the first network device.

[0019] In conjunction with the first aspect, in certain implementations of the first aspect, the first configuration information includes information about the candidate cell's TA public validity duration and information about TA expiration upon exceeding the public validity duration, or information about the candidate cell's TA private validity duration and information about TA expiration upon exceeding the private validity duration. Furthermore, the second configuration information includes a TA public update duration threshold for the candidate cell or a TA private update duration threshold for the candidate cell.

[0020] Among them, the TA public update duration threshold of the candidate cell is a value less than the public effective duration or a value less than the remaining public effective duration; the remaining public effective duration is the difference between the public effective duration and the timing time when the TA timer is started; the TA private update duration threshold of the corresponding candidate cell is a value less than the private effective duration or a value less than the remaining private effective duration, and the remaining private effective duration is the difference between the private effective duration and the timing time when the TA timer is started.

[0021] That is to say, before performing validity management on the TA of the candidate cell, the terminal device also needs to obtain the first configuration information and the second configuration information with multiple combinations, so as to perform validity management on the TA of the candidate cell according to the contents included in the multiple combinations of the first configuration information and the second configuration information, thereby improving the flexibility of terminal device management.

[0022] Optionally, when managing the validity of the TA of the candidate cell according to the first indication information, the method includes: starting the TA timer of the candidate cell to start timing, and if the timing time reaches the TA public update duration threshold or the TA private update duration threshold, triggering the update of the corresponding candidate cell TA.

[0023] That is to say, by starting the TA timer of the candidate cell, the terminal device can trigger the update of the corresponding candidate cell TA when the timing time reaches the TA public update duration threshold or the TA private update duration threshold, thereby improving the timeliness of the terminal device updating the candidate cell TA.

[0024] In combination with the first aspect, in certain implementations of the first aspect, the first configuration information and the second configuration information may be carried in a manner such that: the first configuration information and the second configuration information are carried in a downlink control channel scheduling PDCCH instruction; or, the first configuration information and the second configuration information are carried in an unlimited resource control RRC reconfiguration signaling message; or, the first configuration information is carried in a PDCCH instruction and the second configuration information is carried in an RRC reconfiguration signaling message; or, the first configuration information is carried in an RRC reconfiguration signaling message and the second configuration information is carried in a PDCCH instruction.

[0025] That is, four modes of carrying the first configuration information and the second configuration information are provided, thereby improving the flexibility of transmitting the first configuration information and the second configuration information. Furthermore, by carrying the first configuration information and the second configuration information in a PDCCH instruction or an RRC reconfiguration signaling message, or by carrying the first configuration information in a PDCCH instruction and the second configuration information in an RRC reconfiguration signaling message, or by carrying the first configuration information in an RRC reconfiguration signaling message and the second configuration information in a PDCCH instruction, waste of resources caused by additional transmission can be avoided.

[0026] On this basis, the present application provides four methods for carrying the first configuration information and the second configuration information to improve the flexibility of transmitting the first configuration information and the second configuration information.

[0027] Optionally, when triggering an update of the TA of the corresponding candidate cell, the method includes: sending a CFRA request to the second network device, the CFRA request being used to instruct the second network device to obtain a current TA of the corresponding candidate cell; receiving a CFRA response sent by the second network device, the CFRA response including the current TA of the corresponding candidate cell; and updating the TA of the corresponding candidate cell according to the current TA;

[0028] Alternatively, a current TA measurement process of the candidate cell is performed to obtain the current TA of the candidate cell; and the TA of the corresponding candidate cell is updated according to the current TA.

[0029] In other words, there are two methods for the terminal device to trigger the update of the corresponding candidate cell TA. The first method is that the terminal device triggers a CFRA request to obtain the current TA of the candidate cell, and updates the corresponding candidate cell TA according to the current TA, so that the current TA returned by the second network device can be obtained smoothly. Compared with sending a new instruction to obtain the current TA, transmission resources are saved. The second method is that the terminal device measures the current TA by itself and updates the corresponding candidate cell TA according to the current TA, thereby improving the efficiency of obtaining the latest TA of the candidate cell.

[0030] On this basis, the present application provides two methods to trigger the update of the candidate cell TA, thereby improving the flexibility of managing the effectiveness of the candidate cell TA when managed by the terminal device.

[0031] Optionally, the method further includes: receiving MAC CE signaling sent by the first network device; if a valid target cell TA exists, or if no valid target cell TA exists and the MAC CE signaling includes the target cell TA value, sending a handover indication to a second network device corresponding to the target cell, the handover indication being used to instruct handover to the target cell; and if no valid target cell TA exists and the MAC CE signaling does not include the target cell TA value, performing an uplink synchronization process with the target cell.

[0032] That is, by receiving MAC CE signaling, the terminal device can directly perform handover to the target cell when it determines that the target cell TA currently exists, or when it does not exist but the MAC CE signaling includes the target cell TA. Furthermore, when it determines that the target cell TA currently does not exist and the MAC CE signaling does not include the target cell TA, the terminal device can perform an uplink synchronization process including CFRA with the target cell to obtain a valid target cell TA and then perform handover. This allows the terminal device to perform handover to the target cell while managing the validity of the candidate cell's TA, thereby improving the success rate of handover.

[0033] Optionally, the method also includes: if the device that performs validity management of the TA of the candidate cell is a first network device, sending third indication information to the first network device, wherein the third indication information is used to indicate that the TA or TA value of the corresponding candidate cell has been obtained; if the device that performs validity management of the TA of the candidate cell is a second network device, sending third indication information to the second network device.

[0034] That is, when the terminal device determines that the first network device or the second network device is to manage the validity of the TA of the candidate cell, the first network device or the second network device needs to know the TA of the candidate cell. Therefore, by sending third indication information representing the TA value of the candidate cell or the TA of the corresponding candidate cell to the first network device or the second network device, the terminal device can enable the first network device or the second network device to manage the validity of the TA of the candidate cell based on the TA value of the candidate cell or the TA of the corresponding candidate cell.

[0035] In a second aspect, a timing advance management method is provided, which can be executed by a first network device, or can also be executed by a component (such as a chip or circuit) configured in the first network device. This application does not limit this.

[0036] For example, the method includes: sending first indication information to a terminal device, the first indication information is used to indicate a device that manages the validity of the timing advance TA of the candidate cell; the device that manages the validity of the timing advance TA of the candidate cell is a terminal device or a first network device or a second network device; there are one or more candidate cells; if the device that manages the validity of the TA of the candidate cell is the first network device, then receiving third indication information sent by the terminal device, the third indication information is used to indicate that the TA or TA value of the corresponding candidate cell has been obtained; and managing the validity of the TA of the candidate cell according to the third indication information.

[0037] That is, the first indication information can be sent by the first network device to the terminal device, so that the terminal device can determine the device that manages the validity of the TA of the candidate cell based on the first indication information, and thus the terminal device sends the third indication information to the first network device when it determines that the TA is managed by the first network device. As a result, the first network device can manage the validity of the TA of the candidate cell based on the third indication information, so that multiple devices can manage the timing advance, thereby improving management flexibility.

[0038] In conjunction with the second aspect, in certain implementations of the second aspect, the first network device is a network device to which the source cell belongs, that is, the first network device is a source network device.

[0039] Optionally, the method further includes: sending second indication information to the terminal device, where the second indication information is used to indicate whether the contention-free random access CFRA process includes a random access response RAR.

[0040] That is to say, the first network device can trigger the CFRA process by sending a second indication information to the terminal device, so that the terminal device can successfully obtain the TA returned by the second network device using RAR according to the second indication information, saving transmission resources compared to sending a new instruction to obtain TA.

[0041] In combination with the second aspect, in certain implementations of the second aspect, the carrying manner of the first indication information and the second indication information may be: the first indication information and the second indication information are carried in a physical downlink control channel scheduling PDCCH instruction; or, the first indication information and the second indication information are carried in an unlimited resource control RRC reconfiguration signaling message; or, the first indication information is carried in the PDCCH instruction and the second indication information is carried in the RRC reconfiguration signaling message; or, the first indication information is carried in the RRC reconfiguration signaling message and the second indication information is carried in the PDCCH instruction.

[0042] It should be understood that the PDCCH instruction may also carry CFRA resources used by the terminal device to initiate the CFRA process. The RRC reconfiguration signaling message may also carry candidate cell configuration information.

[0043] Optionally, the method further includes: receiving first configuration information and second configuration information sent by the second network device.

[0044] That is, before managing the validity of the candidate cell's TA, the first network device needs to obtain multiple combinations of first and second configuration information, so as to manage the validity of the candidate cell's TA based on the multiple combinations of first and second configuration information. This improves the management flexibility of the first network device.

[0045] In conjunction with the second aspect, in certain implementations of the second aspect, the first configuration information includes information about the candidate cell's TA public validity duration and information about TA expiration upon exceeding the public validity duration, or information about the candidate cell's TA private validity duration and information about TA expiration upon exceeding the private validity duration. Furthermore, the second configuration information includes a TA public update duration threshold for the candidate cell or a TA private update duration threshold for the candidate cell.

[0046] Among them, the TA public update duration threshold of the candidate cell is a value less than the public effective duration or a value less than the remaining public effective duration; the remaining public effective duration is the difference between the public effective duration and the timing time when the TA timer is started; the TA private update duration threshold of the corresponding candidate cell is a value less than the private effective duration or a value less than the remaining private effective duration, and the remaining private effective duration is the difference between the private effective duration and the timing time when the TA timer is started.

[0047] Optionally, when managing the validity of the TA of the candidate cell according to the third indication information, the method includes: starting the TA timer of the candidate cell to start timing, and if the timing time reaches the TA public update duration threshold or the TA private update duration threshold, triggering the update of the corresponding candidate cell TA.

[0048] That is to say, by starting the TA timer of the candidate cell, the first network device can trigger the update of the corresponding candidate cell TA when the timing time reaches the TA public update duration threshold or the TA private update duration threshold, thereby improving the timeliness of the first network device updating the candidate cell TA.

[0049] In conjunction with the second aspect, in certain implementations of the second aspect, the first configuration information and the second configuration information may be carried in a separate signaling message. Alternatively, the first configuration information may be carried in a separate signaling message and the second configuration information may be carried in another separate signaling message.

[0050] In other words, two methods for carrying the first configuration information and the second configuration information are provided, thereby improving the flexibility of transmitting the first configuration information and the second configuration information. Furthermore, by carrying the first configuration information and the second configuration information in an independent signaling, resource waste caused by additional transmission can be avoided. Alternatively, by carrying the first configuration information and the second configuration information in corresponding independent signaling, the efficiency of parsing the first configuration information and the second configuration information can be improved.

[0051] On this basis, the present application provides two methods for transmitting the first configuration information and the second configuration information, thereby improving the flexibility of transmitting the first configuration information and the second configuration information.

[0052] Optionally, when triggering an update of the corresponding candidate cell TA, the method includes: sending a PDCCH instruction to the terminal device, the PDCCH instruction including random access resource indication information; the random access resource indication information is used to instruct the terminal device to obtain the current TA of the corresponding candidate cell from the second network device through a CFRA request; receiving fourth indication information sent by the terminal device, the fourth indication information is used to indicate that the TA of the corresponding candidate cell has been updated or the updated TA value.

[0053] Alternatively, a measurement instruction is sent to the terminal device, where the measurement instruction is used to instruct the terminal device to perform the current TA measurement process of the candidate cell; and fourth indication information is received from the terminal device, where the fourth indication information is used to indicate that the TA of the corresponding candidate cell or the updated TA value has been updated.

[0054] That is to say, there are two methods to enable the first network device to trigger the update of the corresponding candidate cell TA. The first method is that the first network device sends a PDCCH instruction to the terminal device to trigger a CFRA request, so that the terminal device obtains the current TA of the candidate cell according to the PDCCH instruction, and enables the terminal device to update the corresponding candidate cell TA according to the current TA, thereby enabling the first network device to successfully obtain the latest TA of the candidate cell after the terminal device obtains the current TA returned by the second network device. Compared with obtaining the latest TA of the candidate cell after the terminal device sends a new instruction to obtain the current TA, transmission resources are saved and the timeliness of the first network device obtaining the latest TA of the candidate cell is improved. The second method is to send a measurement instruction to the terminal device so that the terminal device measures the current TA by itself, and enables the terminal device to update the corresponding candidate cell TA according to the current TA, thereby enabling the first network device to obtain the latest TA of the candidate cell after the terminal device obtains the current TA by itself, thereby improving the efficiency of the first network device in obtaining the latest TA of the candidate cell.

[0055] On this basis, the present application provides two methods for triggering the update of the candidate cell TA, thereby improving the flexibility of updating the candidate cell TA when managed by the first network device.

[0056] Optionally, the method also includes: if there is a valid target cell TA, carrying the target cell TA value in the MAC CE signaling; sending MAC CE signaling to the terminal device; the MAC CE signaling is used to instruct the terminal device to send a switching indication to the second network device corresponding to the target cell; if there is no valid target cell TA, not carrying the target cell TA value in the MAC CE signaling; sending MAC CE signaling to the terminal device; the MAC CE signaling is used to instruct the terminal device to perform an uplink synchronization process with the second network device corresponding to the target cell.

[0057] That is, to enable the terminal device to perform a handover to the target cell, the first network device can send MAC CE signaling to the terminal device based on the validity of the target cell TA. Specifically, when the target cell TA is determined to be valid, the first network device sends MAC CE signaling including the target cell TA; when the target cell TA is determined to be invalid, the first network device sends MAC CE signaling excluding the target cell TA. This allows the terminal device to perform a handover based on the MAC CE signaling when the target cell TA is valid, and to perform an uplink synchronization process including CFRA with the second network device corresponding to the target cell when the target cell TA is invalid. This enables handover to be achieved, thereby improving the success rate of handover.

[0058] In a third aspect, a timing advance management method is provided, which can be executed by the second network device, or by a component (eg, a chip or circuit) configured in the second network device. This application does not limit this.

[0059] For example, the method includes: if the device for managing the validity of the TA of the candidate cell is a second network device, receiving a third indication information sent by the terminal device, the third indication information is used to indicate that the TA or TA value of the corresponding candidate cell has been obtained; and managing the validity of the TA of the corresponding candidate cell according to the third indication information.

[0060] In other words, when the terminal device determines that the second network device is responsible for management based on the first indication information, the terminal device can send the third indication information to the second network device, so that the second network device can manage the effectiveness of the TA of the candidate cell. This allows multiple devices to manage the timing advance, improving management flexibility.

[0061] In conjunction with the third aspect, in certain implementations of the third aspect, the third network device is a network device to which the candidate cell belongs, that is, the second network device is a candidate network device.

[0062] Optionally, the method further includes: receiving a CFRA request sent by the terminal device, where the CFRA request is used to instruct the second network device to obtain a TA of the corresponding candidate cell, and the CFRA request is sent by the terminal to the second network device after the first network device sends second indication information to the terminal, and the second indication information is used to indicate whether the contention-free random access CFRA process includes a random access response RAR; if the second indication information indicates that the CFRA process includes the RAR, sending the RAR to the terminal device, where the RAR includes the TA of the corresponding candidate cell;

[0063] or;

[0064] A CFRA request including an RAR is received from a terminal device, where the CFRA request including an RAR is used to indicate that the CFRA process includes an RAR; and the RAR is sent to the terminal device, where the RAR includes a TA corresponding to the candidate cell.

[0065] In other words, there are two scenarios in which the second network device sends a TA to the terminal. First, the second network device receives a CFRA request from the terminal device and, after determining that the CFRA request includes a RAR, sends the RAR with the TA to the terminal device. Second, the second network device directly receives a CFRA request including a RAR from the terminal device and sends the RAR with the TA to the terminal device. This increases the flexibility of the terminal device in obtaining the TA.

[0066] In combination with the third aspect, in certain implementations of the third aspect, the second indication information may be carried in a physical downlink control channel scheduling PDCCH instruction; or, the second indication information may be carried in an unlimited resource control RRC reconfiguration signaling message.

[0067] Optionally, the method includes: acquiring first configuration information and second configuration information corresponding to the candidate cell.

[0068] That is, before managing the validity of the candidate cell's TA, the second network device needs to obtain the first configuration information and the second configuration information in multiple combinations, so as to manage the validity of the candidate cell's TA based on the multiple combinations of the first configuration information and the second configuration information. This improves the management flexibility of the second network device.

[0069] In conjunction with the third aspect, in certain implementations of the third aspect, the first configuration information includes information about the candidate cell's TA public validity duration and information about TA expiration upon exceeding the public validity duration, or information about the candidate cell's TA private validity duration and information about TA expiration upon exceeding the private validity duration. Furthermore, the second configuration information includes a TA public update duration threshold for the candidate cell or a TA private update duration threshold for the candidate cell.

[0070] Among them, the TA public update duration threshold of the candidate cell is a value less than the public effective duration or a value less than the remaining public effective duration; the remaining public effective duration is the difference between the public effective duration and the timing time when the TA timer is started; the TA private update duration threshold of the corresponding candidate cell is a value less than the private effective duration or a value less than the remaining private effective duration, and the remaining private effective duration is the difference between the private effective duration and the timing time when the TA timer is started.

[0071] Optionally, when managing the validity of the TA of the candidate cell according to the third indication information, the TA timer is started for timing. If the timing time reaches the TA public update duration threshold or the TA private update duration threshold, the update of the corresponding candidate cell TA is triggered.

[0072] That is to say, the second network device can trigger the update of the corresponding candidate cell TA when the timing time reaches the TA public update duration threshold or the TA private update duration threshold by starting the TA timer of the corresponding candidate cell. There is no need to trigger the update of the candidate cell TA when the candidate cell TA is about to expire, thereby improving the timeliness of the second network device in updating the candidate cell TA.

[0073] Optionally, when triggering an update of the TA of the corresponding candidate cell, the method includes: sending a first message to the first network device, the first message being used to instruct the first network device to send a PDCCH instruction to the terminal device; receiving a CFRA request sent by the terminal device, the CFRA request being used to instruct the second network device to obtain the current TA of the corresponding candidate cell; sending a CFRA response to the terminal device, the CFRA response including the current TA of the corresponding candidate cell; receiving fourth indication information sent by the terminal device, the fourth indication information being used to indicate that the TA of the corresponding candidate cell or the updated TA value has been updated;

[0074] or;

[0075] A second message is sent to the first network device, where the second message is used to instruct the first network device to send a measurement instruction to the terminal device; and fourth indication information is received from the terminal device, where the fourth indication information is used to indicate that the TA of the corresponding candidate cell or the updated TA value has been updated.

[0076] That is to say, there are two methods for the second network device to trigger the update of the corresponding candidate cell TA. The first is that the second network device instructs the first network device to send a PDCCH instruction, so that the first network device sends a PDCCH instruction to the terminal according to the instruction, and the terminal device obtains the current TA of the candidate cell according to the PDCCH instruction, so that the terminal device updates the corresponding candidate cell TA according to the current TA, and then the terminal device can send the update result to the second network device, thereby enabling the second network device to successfully obtain the latest TA of the candidate cell after the terminal device obtains the returned current TA. Compared with obtaining the latest TA of the candidate cell after the terminal device sends a new instruction to obtain the current TA, transmission resources are saved and the timeliness of the second network device obtaining the latest TA of the candidate cell is improved. The second is that the second network device instructs the first network device to send a measurement instruction, so that the first network device sends a measurement instruction to the terminal device according to the instruction, and enables the terminal device to update the corresponding candidate cell TA according to the current TA after measuring the current TA by itself, and then the terminal device can send the update result to the second network device. This enables the second network device to obtain the latest TA of the candidate cell after the terminal device obtains the current TA on its own, thereby improving the efficiency of the second network device in obtaining the latest TA of the candidate cell.

[0077] On this basis, the present application provides two methods for triggering the update of the candidate cell TA, thereby improving the flexibility of updating the candidate cell TA when managed by the second network device.

[0078] Optionally, the method also includes: receiving a third message sent by the first network device; the third message is used to indicate whether the target cell TA managed by the second network device is valid; sending a fourth message to the first network device, the fourth message including information on whether the target cell TA is valid; the information on whether the target cell TA is valid is used to indicate whether the MAC CE signaling sent by the first network device to the terminal device includes the target cell TA value.

[0079] That is, to enable the terminal device to perform a handover to the target cell, the second network device receives a message from the first network device confirming the validity of the target cell's TA and, based on the message, sends the first network device a result indicating whether the target cell's TA is valid. This allows the first network device to send MAC CE signaling to the terminal device based on the validity of the target cell's TA. The terminal device then performs a handover based on the MAC CE signaling if the target cell's TA is valid. If the target cell's TA is invalid, the terminal device performs an uplink synchronization process, including CFRA, with the second network device corresponding to the target cell. This achieves handover and improves the success rate of handovers.

[0080] In a fourth aspect, a timing advance management device is provided, comprising modules or units for executing the method in the first aspect and any possible implementation manner of the first aspect.

[0081] In a fifth aspect, a timing advance management device is provided, comprising modules or units for executing the method in the second aspect and any possible implementation manner of the second aspect.

[0082] In a sixth aspect, a timing advance management device is provided, comprising modules or units for executing the method in the third aspect and any possible implementation of the third aspect.

[0083] In a seventh aspect, a timing advance management device is provided, comprising a processor. The processor is coupled to a memory and configured to execute instructions or data in the memory to implement the method of the first aspect and any possible implementation of the first aspect. Optionally, the communication device further comprises a memory. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface.

[0084] In one implementation, the timing advance management device is a terminal device. When the timing advance management device is a terminal device, the communication interface may be a transceiver, or an input / output interface.

[0085] In another implementation, the timing advance management device is a chip configured in the terminal device. When the timing advance management device is a chip configured in the terminal device, the communication interface may be an input / output interface.

[0086] Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0087] In an eighth aspect, a timing advance management device is provided, comprising a processor. The processor is coupled to a memory and can be configured to execute instructions or data in the memory to implement the method of the second aspect and any possible implementation of the second aspect. Optionally, the timing advance management device further comprises a memory. Optionally, the timing advance management device further comprises a communication interface, the processor being coupled to the communication interface.

[0088] In one implementation, the timing advance management device is a first network device. When the timing advance management device is a network device, the communication interface may be a transceiver, or an input / output interface.

[0089] In another implementation, the timing advance management device is a chip configured in a network device. When the timing advance management device is a chip configured in a network device, the communication interface may be an input / output interface.

[0090] Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0091] In a ninth aspect, a timing advance management device is provided, comprising a processor. The processor is coupled to a memory and can be configured to execute instructions or data in the memory to implement the method of the third aspect and any possible implementation of the third aspect. Optionally, the timing advance management device further comprises a memory. Optionally, the timing advance management device further comprises a communication interface, the processor being coupled to the communication interface.

[0092] In one implementation, the timing advance management device is a second network device. When the timing advance management device is a network device, the communication interface may be a transceiver, or an input / output interface.

[0093] In another implementation, the timing advance management device is a chip configured in a network device. When the timing advance management device is a chip configured in a network device, the communication interface may be an input / output interface.

[0094] Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0095] In a tenth aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is configured to receive a signal via the input circuit and transmit a signal via the output circuit, so that the processor executes the method of any possible implementation of the first to third aspects and any possible implementation of the first to third aspects.

[0096] In a specific implementation, the processor may be one or more chips, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, or various logic circuits. The input signal received by the input circuit may be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit may be, for example, but not limited to, output to and transmitted by a transmitter. The input circuit and the output circuit may be the same circuit, which functions as an input circuit and an output circuit at different times. The embodiments of the present application do not limit the specific implementation of the processor and various circuits.

[0097] In an eleventh aspect, a processing device is provided, comprising a processor and a memory. The processor is configured to read instructions stored in the memory and receive signals via a receiver and transmit signals via a transmitter to execute the method of any possible implementation of the first to third aspects and any possible implementation of the first to third aspects.

[0098] Optionally, there are one or more processors and one or more memories.

[0099] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0100] In the specific implementation process, the memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or can be set on different chips. The embodiments of the present application do not limit the type of memory and the setting method of the memory and the processor.

[0101] It should be understood that related data interaction processes, such as sending indication information, can be the process of outputting indication information from the processor, and receiving capability information can be the process of receiving input capability information from the processor. Specifically, data output by the processor can be output to the transmitter, and input data received by the processor can be received from the receiver. The transmitter and receiver can be collectively referred to as a transceiver.

[0102] The processing device in the aforementioned eleventh aspect may be one or more chips. The processor in the processing device may be implemented in hardware or software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, or the like; when implemented in software, the processor may be a general-purpose processor implemented by reading software code stored in a memory, which may be integrated into the processor or located independently of the processor.

[0103] In the twelfth aspect, an embodiment of the present application provides a terminal device, including a processor, a memory and a transceiver, the transceiver is used to send and receive data, the memory is used to store code instructions, and the processor is used to run the code instructions. When executing the code instructions stored in the memory, the processor is used to instruct the terminal device to execute the method described in the above-mentioned first aspect and any possible implementation method of the first aspect.

[0104] In the thirteenth aspect, an embodiment of the present application provides a first network device, including a processor, a memory and a transceiver, the transceiver is used to send and receive data, the memory is used to store code instructions, and the processor is used to run the code instructions. When executing the code instructions stored in the memory, the processor is used to instruct the terminal device to execute the method described in the above second aspect and any possible implementation method of the second aspect.

[0105] In the fourteenth aspect, an embodiment of the present application provides a second network device, including a processor, a memory and a transceiver, the transceiver is used to send and receive data, the memory is used to store code instructions, and the processor is used to run the code instructions. When executing the code instructions stored in the memory, the processor is used to instruct the terminal device to execute the method described in the above third aspect and any possible implementation method of the third aspect.

[0106] In the fifteenth aspect, an embodiment of the present application provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is run on a computer, the computer executes the method described in the first to third aspects and any possible implementation of the first to third aspects.

[0107] In a sixteenth aspect, the present application provides a chip or chip system, comprising at least one processor and a communication interface, wherein the communication interface and the at least one processor are interconnected via a line, and the at least one processor is configured to execute a computer program or instruction to perform the method described in any possible implementation of aspects 1 to 3 and any of aspects 1 to 3. The communication interface in the chip may be an input / output interface, a pin, or a circuit.

[0108] In the seventeenth aspect, an embodiment of the present application provides a computer program product comprising a computer program, which, when the computer program is run on a computer, enables the computer to execute the method described in the first to third aspects and any possible implementation of the first to third aspects.

[0109] In one possible implementation, the chip or chip system described above in this application further includes at least one memory, in which instructions are stored. The memory may be a storage unit within the chip, such as a register, a cache, etc., or a storage unit of the chip (e.g., a read-only memory, a random access memory, etc.).

[0110] It should be understood that the fourth, seventh and twelfth aspects of the present application correspond to the technical solution of the first aspect of the present application, the fifth, eighth and thirteenth aspects of the present application correspond to the technical solution of the second aspect of the present application, the sixth, ninth and fourteenth aspects of the present application correspond to the technical solution of the second aspect of the present application, the tenth, eleventh and fifteenth to seventeenth aspects of the present application correspond to the technical solutions of the first to third aspects of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0111] FIG1 is a schematic diagram of the architecture of a communication system 1000 used in an embodiment of the present application;

[0112] FIG1a is a diagram exemplarily illustrating signaling interactions between a terminal device and each network device in an LTM switching process;

[0113] FIG2 is a schematic flow chart of a timing advance management method 200 provided in an embodiment of the present application, shown from the perspective of device interaction;

[0114] FIG3 is a diagram of signaling interactions between a terminal device and each network device when acquiring a candidate cell TA according to an embodiment of the present application;

[0115] 4 is a diagram of signaling interactions between a terminal device and each network device when the terminal device manages the timing advance according to an embodiment of the present application;

[0116] 5 is a diagram of signaling interactions between a terminal device and each network device when the timing advance is managed by a first network device according to an embodiment of the present application;

[0117] 6 is a diagram of signaling interactions between a terminal device and each network device when the timing advance is managed by a second network device according to an embodiment of the present application;

[0118] FIG7 is a schematic block diagram of a timing advance management device 70 provided in an embodiment of the present application;

[0119] FIG8 is a schematic diagram of a possible structure of a terminal device 8000 provided in an embodiment of the present application;

[0120] FIG9 is a schematic diagram of a possible structure of a network device 9000 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0121] To facilitate understanding of the timing advance management method, device, storage medium, and product provided in the embodiments of the present application, the timing advance management method, its system architecture, and application scenarios provided in the embodiments of the present application are described below. It is understood that the system architecture and application scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application.

[0122] The technical solutions of the embodiments of the present application can be applied to communication scenarios in various communication systems, such as: Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, future fifth generation (5G) communication system or new radio access technology (NR), vehicle-to-X (V2X), where V2X may include vehicle-to-network (V2N), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), etc., Long Term Evolution-Vehicle (LTE-V), Internet of Vehicles, machine type communication (MTC), etc. communication (MTC), Internet of Things (IoT), Long Term Evolution-Machine (LTE-M), Machine to Machine (M2M), etc.

[0123] Furthermore, the present application can be applied to specific communication scenarios with an uplink synchronization process for candidate cells when performing cell switching, for example, it can be a cell switching communication scenario of the LTM mechanism, it can also be a cell switching communication scenario of the conditional LTM mechanism, it can also be a cell switching communication scenario of the CHO / CPC mechanism, or it can be a cell switching communication scenario triggered under dual connection. The present application does not limit the specific switching scenario.

[0124] To facilitate understanding of the embodiments of the present application, a communication system 1000 applicable to the embodiments of the present application is first described in detail in conjunction with Figure 1. Figure 1 is a schematic diagram of the architecture of the communication system 1000 applied in the embodiments of the present application. As shown in Figure 1, the communication system 1000 may include at least one terminal device, such as the terminal device 1001 shown in Figure 1; it may also include a first network device, such as the source cell network device 1002 shown in Figure 1; it may also include at least one second network device, such as the candidate cell network device 1003 shown in Figure 1. Among them, the terminal device 1001 can be mobile or fixed. The first network device 1002 and the second network device 1003 are devices that can communicate with the terminal device 1001 via a wireless link, such as a base station or a base station controller. The first network device 1002 can provide communication coverage for a specific geographical area, and can communicate with terminal devices located in the coverage area (cell).

[0125] Figure 1 exemplarily shows a terminal device, a first network device, and a second network device. Optionally, the communication system 1000 may include multiple second network devices, and the coverage range of the first network device and the second network device may include other numbers of terminal devices, which is not limited in this embodiment of the present application.

[0126] Each of the above-mentioned communication devices, such as the terminal device 1001, the first network device 1002 or the second network device 1003 in Figure 1, can be configured with multiple antennas. The multiple antennas may include at least one transmitting antenna for sending signals and at least one receiving antenna for receiving signals. In addition, each communication device also additionally includes a transmitter chain and a receiver chain. It can be understood by those skilled in the art that they can all include multiple components related to signal transmission and reception (such as processors, modulators, multiplexers, demodulators, demultiplexers or antennas, etc.). Therefore, the first network device 1002 or the second network device 1003 can communicate with the terminal device 1001 through multi-antenna technology.

[0127] Optionally, the wireless communication system 1000 may further include other network entities such as a network controller and a mobility management entity, but the embodiments of the present application are not limited thereto.

[0128] In the embodiment of the present application, the network device can be any device with wireless transceiver function. The device includes but is not limited to: evolved Node B (eNB), Radio Network Controller (RNC), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), Home Base Station (e.g., Home evolved NodeB, or Home Node B, HNB), Base Band Unit (BBU), Access Point (AP) in Wireless Fidelity (WIFI) system, wireless relay node, wireless backhaul node, transmission point (TP) or transmission and reception point (TRP), etc., and can also be a gNB in ​​5G, such as NR, system, or a transmission point (TRP or TP), one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DU), etc.

[0129] In some deployments, a gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU is responsible for processing non-real-time protocols and services, and implementing radio resource control (RRC) and packet data convergence protocol (PDCP) layer functions. The DU is responsible for processing physical layer protocols and real-time services, and implementing radio link control (RLC), media access control (MAC), and physical (PHY) layer functions. The AAU implements some physical layer processing functions, RF processing, and active antenna-related functions. Because RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by both the DU and the AAU. It is understood that the primary cell network device can be a device that includes one or more of the following: a CU node, a DU node, or an AAU node. In addition, the CU may be classified as a network device in an access network (radio access network, RAN), or may be classified as a network device in a core network (core network, CN), which is not limited in this application.

[0130] Network equipment provides services for cells, and terminal devices communicate with cells through transmission resources allocated by the network equipment (for example, frequency domain resources, or spectrum resources). The cell can belong to a macro base station (for example, a macro eNB or macro gNB), or to a base station corresponding to a small cell. Small cells here can include: metro cells, micro cells, pico cells, femto cells, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

[0131] In an embodiment of the present application, the terminal device may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, 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 can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, 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, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolved public land mobile communication network (PLMN), etc.

[0132] Wearable devices, also known as wearable smart devices, are a general term for wearable devices that use wearable technology to intelligently design and develop wearable devices for daily wear, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not just hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. In a broad sense, wearable smart devices include those that are fully functional, large in size, and can achieve full or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0133] Furthermore, the terminal device can also be a terminal device in the Internet of Things (IoT) system. IoT is an important component of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network that interconnects people, machines, and things.

[0134] This application does not limit the specific form of the terminal device.

[0135] To facilitate understanding of the embodiments of the present application, a brief explanation of the terms involved in the present application is first given.

[0136] 1. Cell: A cell is described at a high level from the perspective of resource management, mobility management, or service unit. The coverage area of ​​each network device can be divided into one or more cells, and each cell can correspond to one or more frequencies. In other words, each cell can be considered an area formed by the coverage area of ​​one or more frequencies.

[0137] It should be noted that a cell can be an area within the coverage range of a wireless network of a network device. In an embodiment of the present application, different cells can correspond to the same or different network devices. For example, the network device to which cell #1 belongs and the network device to which cell #2 belongs can be different network devices, such as a base station. That is, cell #1 and cell #2 can be managed by different base stations. Or, for another example, the network device that manages cell #1 and the network device that manages cell #2 can also be different radio frequency processing units of the same base station, such as a radio remote unit (RRU). That is, cell #1 and cell #2 can be managed by the same base station, have the same baseband processing unit and intermediate frequency processing unit, but have different radio frequency processing units. Or, for another example, the network device to which cell #1 belongs and the network device to which cell #2 belongs can be the same network device, such as a base station. That is, cell #1 and cell #2 can be managed by the same base station. In this case, it can be said that cell #1 and cell #2 are co-located. This application does not specifically limit this.

[0138] In some possible deployments, a base station may include both a CU and a DU. In this deployment, cell #1 and cell #2 may be managed by the same CU and the same DU, i.e., they share both the CU and the DU. Cell #1 and cell #2 may be managed by the same CU and different DUs, i.e., they share both the CU and the DU. Cell #1 and cell #2 may also be managed by different CUs and different DUs, i.e., they share neither the CU nor the DU.

[0139] 2. Handover: In a wireless communication system, when a terminal device moves from one cell to another or approaches another cell, a handover is required to maintain uninterrupted communication with the terminal device. In the embodiment of the present application, the source cell represents the cell that provided services to the terminal device before the handover, the candidate cell represents the potential cell that may provide services to the terminal device after the handover, and the target cell represents the cell among the candidate cells that ultimately provides services to the terminal device.

[0140] The relevant information of the candidate cell (such as the physical cell identification, frequency information, random access resource information required to switch to the candidate cell, etc.) can be indicated by a switching message, which is sent by the network device to which the source cell belongs (i.e., the source network device) to the terminal device through an RRC reconfiguration signaling message.

[0141] A handover may be an intra-site handover or an inter-site handover. An intra-site handover may refer to a situation where the source cell and the candidate cell belong to the same network device (e.g., a base station), where the source cell and the candidate cell may be the same cell or different cells; an inter-site handover may refer to a situation where the source cell and the candidate cell belong to different network devices (e.g., base stations). This application does not limit this.

[0142] It should be understood that a cell is a coverage area of ​​a network device, a source cell corresponds to a source network device (eg, a source base station), and a candidate cell corresponds to a candidate network device (eg, a candidate base station).

[0143] It should also be understood that the source cell and the candidate cell may belong to the same network device, or in other words, the source cell and the candidate cell may be co-located. In this case, for a certain terminal device, the TA corresponding to the candidate cell may be equal to the TA corresponding to the source cell. The candidate cell may also be a small cell. In this case, for a certain terminal device, the timing advance TA of the candidate cell may be 0.

[0144] In traditional handover processes, the mobility management of terminal devices is controlled by network equipment. Specifically, the network equipment sends a handover message to instruct the terminal device which cell to switch to and how to perform the handover. For example, the source network equipment sends a handover message to the terminal device to control the terminal device's handover from the source cell to the target cell. This handover message can be an RRC message.

[0145] 3. LTM Handover Process: This is also known as the Layer 1 / 2 Triggered Mobility Handover Process. Handover decisions are made by the base station based on measurement reports submitted by the terminal device. Figure 1a illustrates the signaling interactions between the terminal device and various network devices during the LTM handover process. The LTM handover process is briefly described below with reference to Figure 1a. The LTM handover process specifically includes S101 to S110.

[0146] S101. The terminal device in the connected state reports the measurement results to the source cell network device.

[0147] S102. The source cell network device sends an LTM handover request to the candidate cell network device after determining to execute LTM according to the terminal's support capability for LTM. The candidate cell includes a target cell and a potential target cell. There are one or more candidate cells.

[0148] S103: The candidate cell network device sends an LTM handover response to the source cell network device. The LTM handover response includes candidate cell configuration information.

[0149] S104. The source cell network device sends the candidate cell configuration information to the terminal device via an RRC reconfiguration message.

[0150] S105. The terminal device performs downlink synchronization on each candidate cell according to the candidate cell configuration information.

[0151] S106. The terminal device performs uplink synchronization on each candidate cell according to the candidate cell configuration information.

[0152] When performing uplink synchronization, it involves managing the timing advance (TA) of the candidate cell during uplink synchronization. One way is for the source cell network device to trigger a non-contention random access process through a PDCCH order to obtain the timing advance (TA) of the candidate cell and manage the validity of the timing advance (TA) of the candidate cell.

[0153] S107. The terminal device performs L1 measurement on the source cell and the candidate cells and reports the measurement results to the source cell network device.

[0154] S108. The source cell network device determines the target cell according to the measurement result and issues an LTM handover command, where the LTM handover command includes a MAC CE.

[0155] S109. The terminal device disconnects from the source cell network device when the timing advance TA is included in the MAC CE.

[0156] S110. The terminal device initiates a handover instruction to the target cell to complete the LTM handover.

[0157] 4. Timing Advance: TA refers to the time required to advance the downlink transmission time of a terminal device during uplink synchronization. Terminal devices generally obtain TA in two ways. First, the source cell network equipment provides CFRA resources to the terminal device via a PDCCH order, enabling the terminal device to trigger a CFRA request based on the CFRA resources to obtain TA. Second, the source cell network equipment instructs the terminal device to measure TA independently, allowing the terminal device to measure TA accordingly.

[0158] It should be understood that the above two terminal devices obtain TA methods for example only and should not constitute any limitation to this application.

[0159] 5. TA validity management: When performing a handover, it should be ensured that the TA obtained by the terminal device is valid before the handover can be directly initiated to the target cell. The process of ensuring that the TA obtained by the terminal device is valid is called TA validity management.

[0160] 6. Non-contention random access process: CFRA, the process from when the terminal device starts sending a random access preamble index to the network device attempting to access, to when a connection is established between the terminal device and the network device. Specifically, the terminal device sends a random access preamble index (or random access preamble sequence) to the network device through PRACH. In the non-contention random access process, the random access preamble index is allocated to the terminal device in advance by the network device. In other words, the random access preamble index is dedicated. The network device sends a random access response to the terminal device. The random access response may include a TA for the response.

[0161] 7. CFRA with RAR: When a terminal device initiates a CFRA with a network device, it simultaneously initiates a request to obtain the RAR. Specifically, the terminal device sends the CFRA request to the network device based on the need to obtain the RAR. The network device then sends the RAR protocol including the TA to the terminal device.

[0162] 8. MAC CE signaling message: This message is required by the terminal device to perform handover. The MAC CE signaling message may include a timing advance (TA), a transmission configuration indicator, CFRA resource information, and a candidate cell configuration identifier. The timing advance (TA) is included in the MAC CE signaling message only if the source cell network equipment determines it is valid.

[0163] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0164] To facilitate understanding of the embodiments of the present application, the following description is first made:

[0165] First, to clearly describe the technical solutions of the embodiments of this application, the embodiments of this application use terms such as "first" and "second" to distinguish between identical or similar items with substantially identical functions and effects. For example, the first retention indication information and the second retention indication information are merely used to distinguish between different retention indication information and do not limit their order. Those skilled in the art will understand that terms such as "first" and "second" do not limit the quantity or execution order, and do not necessarily indicate differences.

[0166] Second, in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0167] Third, in the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, a--c, bc, or abc, where a, b, c can be single or multiple.

[0168] Fourth, in the embodiments of the present application, "when", "if" and "if" all mean that the device will perform corresponding processing under certain objective circumstances, which does not limit the time, nor does it require that the device must perform a judgment action when it is implemented, nor does it mean that there are other limitations.

[0169] Fifth, the "simultaneously" in the embodiments of the present application can be understood as at the same time point, or within a period of time, or within the same cycle, and can be understood specifically in conjunction with the context.

[0170] Sixth, in each embodiment of the present application, "A corresponds to B" means that B is associated with A. "Executing B according to A" does not mean executing B only according to A, but B can also be executed according to A and / or other information.

[0171] Seventh, "pre-definition" or "pre-configuration" can be achieved by pre-saving corresponding codes, tables or other methods that can be used to indicate relevant information in a device (for example, including a terminal device and a network device). This application does not limit its specific implementation method. Among them, "saving" may mean saving in one or more memories. One or more memories may be set separately, or integrated in an encoder or decoder, a processor, or a timing advance management device. One or more memories may also be partially set separately, and partially integrated in a decoder, a processor, or a timing advance management device. The type of memory may be any form of storage medium, and this application does not limit it.

[0172] The predefined in this application may be understood as defined, predefined, stored, pre-stored, pre-negotiated, pre-configured, solidified, or pre-burned.

[0173] Eighth, the "protocol" involved in the embodiments of the present application may refer to a standard protocol in the communication field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems. This application does not limit this.

[0174] Ninth, in an embodiment of the present application, "used for indication" may include direct indication and indirect indication, and may also include explicit indication and implicit indication. The information indicated by a certain information is called information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, such as but not limited to, the information to be indicated can be directly indicated, such as the information to be indicated itself or the index of the information to be indicated. The information to be indicated can also be indirectly indicated by indicating other information, wherein the other information and the information to be indicated have an association relationship. It is also possible to indicate only a part of the information to be indicated, while the other parts of the information to be indicated are known or agreed in advance. For example, it is also possible to implement the indication of the information to be indicated by means of a pre-agreement (such as a protocol provision) on whether a certain information element exists, thereby reducing the indication overhead to a certain extent.

[0175] Tenth, the following describes various embodiments in detail with reference to various flowcharts. However, it should be understood that these flowcharts and the descriptions of their corresponding embodiments are provided for ease of understanding only and should not constitute any limitation on this application. Not every step in each flowchart is necessarily required; for example, some steps can be skipped. Furthermore, the order in which the steps are executed is not fixed and is not limited to that shown in the figures. The order in which the steps are executed should be determined by their functions and inherent logic.

[0176] When the terminal device is in a network connection state, it may trigger a cell change due to the poor current network, which involves the uplink synchronization process between the terminal device and the candidate cell. In order to ensure that information can be transmitted synchronously during the change process, the terminal device will be triggered to execute the acquisition of the timing advance TA of the candidate cell, and it is necessary to manage the effectiveness of the acquired TA of the candidate cell. In this regard, one way to manage the effectiveness of the TA of the candidate cell is to manage it directly by the network device, which makes the flexibility of managing the effectiveness of the TA of the candidate cell less. In this regard, an embodiment of the present application provides a method for managing the timing advance, and its main inventive ideas are as follows:

[0177] In order to improve the flexibility of managing the effectiveness of the candidate cell's TA, instead of just the network device managing the effectiveness of the candidate cell's TA, a method for implementing terminal device management of the effectiveness of the candidate cell's TA is added. This allows the terminal device to manage the effectiveness of the candidate cell's TA based on the specific device indicated. When the terminal device is determined to be the indicated terminal device, the terminal device directly manages the effectiveness of the candidate cell's TA based on the indicated specific device. When the source cell network device is determined to be the indicated source cell network device, the terminal device notifies the source cell network device of the result of obtaining the candidate cell's TA. The source cell network device then manages the effectiveness of the candidate cell's TA. When the candidate cell network device is determined to be the indicated candidate cell network device, the terminal device notifies the candidate cell network device of the result of obtaining the candidate cell's TA. The terminal cell network device then manages the effectiveness of the candidate cell's TA. This allows both the terminal device and the network device to manage the timing advance, improving the flexibility of timing advance management.

[0178] The method provided in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0179] It should be understood that the following description is only for ease of understanding and explanation, and the method provided in the embodiment of the present application is described in detail using the interaction between a terminal device and a network device as an example. However, this does not constitute any limitation on the execution subject of the method provided in the present application. For example, the terminal device shown in the embodiment below can be replaced by a component (such as a chip or circuit) configured in the terminal device. The network device shown in the embodiment below can also be replaced by a component (such as a chip or circuit) configured in the network device.

[0180] The embodiments shown below do not particularly limit the specific structure of the execution subject of the method provided in the embodiments of the present application. As long as it is possible to communicate according to the method provided in the embodiments of the present application by running a program that records the code of the method provided in the embodiments of the present application, for example, the execution subject of the method provided in the embodiments of the present application can be a terminal device or a network device, or a functional module in the terminal device or the network device that can call and execute the program.

[0181] Figure 2 is a schematic flow chart illustrating a timing advance management method 200 provided by an embodiment of the present application from the perspective of device interaction. As shown in Figure 2, the method 200 may include steps 201 to 204. Each step in the method 200 is described in detail below.

[0182] In step 201, the first network device sends a first indication message to the terminal device, where the first indication message is used to indicate a device that manages the validity of the timing advance TA of the candidate cell. The device that manages the validity of the timing advance TA of the candidate cell is the terminal device or the first network device or the second network device, and the candidate cell is one or more.

[0183] It should be understood that the specific application scenario for managing the validity of the timing advance (TA) of a candidate cell is when a cell handover is currently being performed. This involves three devices: a terminal device, a first network device representing a source cell network device, and a second network device representing a candidate cell network device. Therefore, the device for managing the validity of the timing advance (TA) of the candidate cell can be selectively indicated in the first indication information. The specific indication method in the first indication information is described below.

[0184] In one example, the first indication information may include device information corresponding to a device that manages the validity of the timing advance TA of the candidate cell. When the first indication information includes device information corresponding to a terminal device, it indicates that the terminal device manages the validity of the timing advance TA of the candidate cell. Similarly, when the first indication information includes device information corresponding to a first network device, it indicates that the first network device manages the validity of the timing advance TA of the candidate cell. Similarly, when the first indication information includes device information corresponding to a second network device, it indicates that the second network device manages the validity of the timing advance TA of the candidate cell.

[0185] In another example, the first indication information may include device information corresponding to a device that does not perform validity management on the timing advance TA of the candidate cell. When the first indication information includes device information corresponding to the first network device and the second network device, it indicates that the terminal device performs validity management on the timing advance TA of the candidate cell. Similarly, when the first indication information includes device information corresponding to the terminal device and the second network device, it indicates that the first network device performs validity management on the timing advance TA of the candidate cell. Similarly, when the first indication information includes device information corresponding to the terminal device and the first network device, it indicates that the second network device performs validity management on the timing advance TA of the candidate cell.

[0186] In order to further save transmission resources, the device information in the first indication information may be replaced with an identifier or number corresponding to a device that manages the validity of the timing advance TA of the candidate cell, and this application does not impose any limitation on this.

[0187] In another example, the first indication information may include three predefined fields in a fixed order, and the device that performs validity management on the timing advance TA of the candidate cell is determined based on the values ​​of the predefined fields. For example, the fixed order is the predefined field corresponding to the terminal device, the predefined field corresponding to the first network device, and the predefined field corresponding to the second network device. When the value of the predefined field is the first numerical value, it indicates that the device corresponding to the predefined field is a device that performs validity management on the timing advance TA of the candidate cell. When the value of the predefined field is the second numerical value, it indicates that the device corresponding to the predefined field is not a device that performs validity management on the timing advance TA of the candidate cell. For example, the first numerical value can be 1, and the second numerical value can be 0. Or the first numerical value can be 0, the second numerical value can be 1, etc. The specific values ​​of the first numerical value and the second numerical value are not limited in this embodiment.

[0188] In another example, the first indication information may include a fixed predefined field, and the device that manages the validity of the timing advance TA of the candidate cell is determined based on the value of the predefined field. Exemplarily, when the value of the predefined field is a third numerical value, it indicates that the device that manages the validity of the timing advance TA of the candidate cell is a terminal device, when the value of the predefined field is a fourth numerical value, it indicates that the device that manages the validity of the timing advance TA of the candidate cell is a first network device, and when the value of the predefined field is a fifth numerical value, it indicates that the device that manages the validity of the timing advance TA of the candidate cell is a second network device. Exemplarily, the third numerical value may be 1, the fourth numerical value may be 2, and the fifth numerical value may be 3. It is understandable that the third numerical value, the fourth numerical value, or the fifth numerical value may also be other specific values, which are not limited in this embodiment.

[0189] It should be understood that the specific indication methods in the first indication information listed above are only examples and should not constitute any limitation to this application. This application does not limit the specific method of how the first network device instructs the device for managing the validity of the timing advance TA of the candidate cell.

[0190] In step 202, if the device that performs validity management on the TA of the candidate cell is a terminal device, the terminal device performs validity management on the TA of the candidate cell according to the first indication information.

[0191] In other words, the terminal device can determine the device for which validity management of the candidate cell's TA will be performed based on the content included in the first indication information. If the terminal device is determined to be the terminal device, the terminal device performs validity management of the candidate cell's TA based on the acquired candidate cell's TA. The process of acquiring the candidate cell's TA will be described in detail in the next embodiment.

[0192] In step 203, if the device performing validity management of the TA of the candidate cell is the first network device, the terminal device sends third indication information to the first network device, and the first network device performs validity management of the TA of the candidate cell according to the third indication information. The third indication information is used to indicate that the TA or TA value of the corresponding candidate cell has been obtained.

[0193] In other words, when the terminal device determines that the device for managing the validity of the TA of the candidate cell is the first network device, it forms a third indication information based on the TA of the candidate cell that has been acquired, and sends the third indication information to the first network device. The first network device manages the validity of the TA of the candidate cell based on the third indication information.

[0194] Then, when forming the third indication information, the following two implementation methods may be specifically included:

[0195] One possible implementation method is to form the third indication information according to the TA value of the candidate cell that has been obtained. Specifically, the TA value of the candidate cell is associated with the candidate cell identifier. For example, a mapping relationship is established between the TA value of the candidate cell and the corresponding candidate cell identifier to form the third indication information according to the association result.

[0196] Another possible implementation is to form the third indication information based on the result of obtaining the TA of the candidate cell. Specifically, a series of specific fields is formed based on the result of obtaining the TA of the candidate cell, and the specific fields corresponding to the candidate cell are associated with the candidate cell identifier. For example, a mapping relationship is established between the specific fields corresponding to the candidate cell and the corresponding candidate cell identifier, and the third indication information is formed based on the association result. The specific field indicates that the TA of the candidate cell has been obtained.

[0197] It is understandable that the mapping relationship may be expressed in the form of a mapping table or other forms, which is not limited in this embodiment.

[0198] The candidate cell identifier is an identifier indicating the identity of the candidate cell, for example, it can be the name of the candidate cell, or it can be a number, letter or other information representing the identity of the candidate cell, which is not limited in this application.

[0199] It should be understood that when there are multiple candidate cells, the third indication information can be formed according to the TA values ​​of all candidate cells that have been obtained. Alternatively, the third indication information can be formed according to the result of obtaining the TA values ​​of all candidate cells. Alternatively, the third indication information can be formed according to the result of obtaining the TA values ​​of some candidate cells and the result of obtaining the TA values ​​of another part of the candidate cells. The specific form of the third indication information is not limited in this application.

[0200] In step 204, if the device that manages the validity of the TA of the candidate cell is the second network device, the terminal device sends third indication information to the second network device, and the second network device manages the validity of the TA of the corresponding candidate cell according to the third indication information.

[0201] As before, when the terminal device determines that the device for managing the validity of the TA of the candidate cell is the second network device, it forms a third indication information based on the TA of the candidate cell that has been obtained, and sends the third indication information to the second network device. The second network device manages the validity of the TA of the candidate cell based on the third indication information.

[0202] It should be understood that the manner of forming the third indication information here is similar to the manner of forming the third indication information in step 203 , and will not be described in detail here.

[0203] Therefore, the timing advance management method provided in the embodiment of the present application provides three ways to manage the effectiveness of the TA of one or more candidate cells, namely, managing the effectiveness of the TA based on the terminal device, the first network device, or the second network device. By receiving the first indication information sent by the first network device, the terminal device can manage the effectiveness of the TA of the candidate cell when it is determined that the first indication information indicates the terminal device, the first network device can manage the effectiveness of the TA of the candidate cell when it is determined that the first indication information indicates the first network device, and the second network device can manage the effectiveness of the TA of the candidate cell when it is determined that the first indication information indicates the second network device. This makes it not limited to management by only the network device, and improves the flexibility of TA management.

[0204] In the method of the present application, the premise for managing the validity of the TA of the candidate cell is that the terminal device has acquired the TA of at least one candidate cell. Therefore, the method of acquiring the TA of at least one candidate cell is described.

[0205] In one possible implementation, as shown in Figure 3, when a first network device sends first indication information to a terminal device, in step 301, the first network device may also send second indication information to the terminal device. The second indication information is used to indicate whether the contention-free random access (CFRA) process includes a random access response (RAR). In step 302, the terminal device sends a CFRA request to a second network device based on the second indication information. The CFRA request is used to instruct the second network device to obtain the TA of the corresponding candidate cell. In step 303, the second network device determines whether the CFRA process includes an RAR based on the CFRA request. If so, in step 304, the second network device sends the RAR to the terminal device. The RAR includes the TA of the corresponding candidate cell.

[0206] It should be understood that the terminal device may send a CFRA request to the second network device according to the content included in the second indication information, wherein the second indication information includes: whether RAR is included in the CFRA process.

[0207] When the second indication information indicates whether the CFRA process includes RAR, the second indication information may include a predefined field containing the indication information indicating whether the CFRA process includes RAR. For example, the predefined field may be the sixth value or the seventh value. The sixth value or the seventh value may be other information such as predefined numbers, letters, or symbols, which is not limited in this application.

[0208] The sixth value may be information indicating that RAR is included in the CFRA process, and the seventh value may be information indicating that RAR is not included in the CFRA process. Alternatively, the seventh value may be information indicating that RAR is included in the CFRA process, and the sixth value may be information indicating that RAR is not included in the CFRA process. This application is not limited to this.

[0209] Exemplarily, if the value of the predefined field in the second indication information is 1, it indicates that the indication information of RAR is included in the CFRA process; if the value of the predefined field is 0, it indicates that the indication information of RAR is not included in the CFRA process.

[0210] In addition, the second indication information can also implicitly express whether the indication information of RAR is included in the CFRA process. For example, the second indication information can be information such as the field of "include RAR", the identifier of "include RAR", the index of "include RAR", etc., and the above indication information can be used to express that RAR is included in the CFRA process. If the second indication information is not the field of "include RAR", the identifier of "include RAR", the index of "include RAR", etc., but is information unrelated to "include RAR", such as NULL or the field of "not include RAR", the identifier of "not include RAR", the index of "not include RAR", etc., it can represent the indication information of not including RAR in the CFRA process.

[0211] Based on this, the terminal device has two options for initiating a CFRA request to the second network device. One is to initiate a CFRA process to the second network device without including a RAR, and the other is to initiate a CFRA process to the second network device with a RAR. Therefore, after receiving the CFRA request from the terminal device, the second network device needs to determine whether the CFRA process includes a RAR. If so, it stores the TA of the corresponding candidate cell in the RAR and sends the RAR to the terminal device.

[0212] When the second network device determines whether the CFRA process includes RAR, it can be performed in the following manner:

[0213] In one example, when a terminal device initiates a CFRA procedure that does not include a RAR, the terminal device does not include "include RAR"-related indication information in the CFRA request. For example, it includes "excluding RAR"-related indication information or sets a blank value. When a terminal device initiates a CFRA procedure that includes a RAR, the terminal device includes "include RAR"-related indication information in the CFRA request. Accordingly, when the second network device determines whether the CFRA procedure includes a RAR, it can determine whether the CFRA procedure includes a RAR based on the content of the received CFRA request.

[0214] In another example, when a terminal device initiates a CFRA process that includes RAR, the terminal device generates independent signaling related to "including RAR" and sends the signaling together with the CFRA request to the second network device. When a terminal device initiates a CFRA process that does not include RAR, the terminal device generates independent signaling related to "not including RAR" and sends the signaling together with the CFRA request to the second network device. Alternatively, the terminal device does not generate any signaling and only sends the CFRA request to the second network device. Accordingly, when the second network device determines whether the CFRA process includes RAR, it determines whether the CFRA process includes RAR based on the CFRA request or determines whether the CFRA process includes RAR based on the CFRA request and the signaling sent along with the CFRA request.

[0215] It should also be understood that this application does not limit the specific forms of the indication information related to "including RAR", the indication information related to "excluding RAR", the independent signaling related to "including RAR", and the independent signaling related to "excluding RAR". The above examples are merely illustrative and should not constitute any limitation on this application.

[0216] It should also be understood that the content included in the above-mentioned second indication information is only an example and should not constitute any limitation to this application. Therefore, in the above-mentioned method for obtaining the TA of at least one candidate cell, by using the second indication information to trigger the terminal device to decide whether the CFRA process includes RAR, the terminal device can use RAR to successfully obtain the TA returned by the second network device after initiating the CFRA process including RAR. Compared with sending a new instruction to obtain the TA, this saves transmission resources.

[0217] Another possible implementation is that the terminal device sends a CFRA request including an RAR to the second network device, where the CFRA request including the RAR is used to indicate that the CFRA process includes the RAR. The second network device sends the RAR to the terminal device, where the RAR includes the TA of the corresponding candidate cell.

[0218] It should be noted that, in this possible implementation, the terminal device triggers the CFRA process including the RAR on its own based on the first indication information to obtain the RAR including the TA of the corresponding candidate cell sent by the second network device.

[0219] In other words, the difference between this implementation and the previous implementation is that, in this implementation, the terminal device does not need to receive the second indication information sent by the first network device, and can spontaneously trigger the CFRA process including RAR after receiving the first indication information sent by the first network device. Among them, the spontaneous triggering of the CFRA process including RAR is similar to the method adopted when the terminal device initiates the CFRA process including RAR in the previous implementation, and will not be repeated here. Therefore, in the above-mentioned method for obtaining the TA of at least one candidate cell, the efficiency of obtaining the TA of the candidate cell is improved by triggering the terminal device to automatically send the execution action of the CFRA request including RAR.

[0220] It should be understood that the present application may adopt one of two methods to obtain the TA of the candidate cell, thereby effectively improving the flexibility of obtaining the TA of the candidate cell.

[0221] Based on the above two possible implementation methods, further explanation is required, that is, the premise for the terminal device to send a CFRA-related request to the second network device is that the terminal device has currently acquired CFRA resources. This involves the terminal device sending a CFRA resource acquisition request to the first network device, the first network device storing the CFRA resources in a PDCCH instruction, and returning the PDCCH instruction to the terminal device to enable it to obtain CFRA resources. The CFRA resource acquisition request is a request to obtain CFRA resources. The CFRA resource includes the random access occasion RACH occasion and the random access preamble index Preamble index. The RACH occasion is used to indicate at which time the terminal device initiates CFRA, and the Preamble index is used to indicate on which preamble the terminal device performs CFRA.

[0222] It should be understood that the term "CFRA-related request" is a general term for CFRA requests and CFRA requests that include RARs. References to CFRA-related requests should be understood as referring to either CFRA requests or CFRA requests that include RARs. References to CFRA-related requests should not be separated from CFRA requests or CFRA requests that include RARs.

[0223] It should also be understood that when the first network device sends the first indication information and the second indication information to the terminal device, they can be sent together or separately, and the specific sending method is not limited in this application. The transmission method of the first indication information and the second indication information is described in detail below.

[0224] In one example, the first indication information and the second indication information can be carried in a physical downlink control channel scheduling PDCCH instruction. Specifically, when the terminal device sends a CFRA resource acquisition request to the first network device, the first network device sends the first indication information and the second indication information together with the PDCCH instruction to the terminal device. In this case, the first indication information and the second indication information can be a predefined field in the PDCCH instruction. This method of carrying the first indication information and the second indication information in the PDCCH instruction at the same time can avoid resource waste caused by additional transmission.

[0225] In another example, the first indication information and the second indication information are carried in an RRC reconfiguration signaling message. Specifically, when the first network device obtains candidate cell configuration information under a certain cell handover mechanism and forms an RRC reconfiguration signaling message based on the candidate cell configuration information, the first network device sends the first indication information and the second indication information together with the RRC reconfiguration signaling message to the terminal device. In this case, the first indication information and the second indication information can each be a predefined field in the RRC reconfiguration signaling message. This method of carrying the first indication information and the second indication information simultaneously in the RRC reconfiguration signaling message can also avoid resource waste caused by additional transmission.

[0226] In another example, the first indication information is carried in a PDCCH instruction and the second indication information is carried in an RRC reconfiguration signaling message. Specifically, when the terminal device sends a CFRA resource acquisition request to the first network device, the first network device sends the first indication information together with the PDCCH instruction to the terminal device. When the first network device obtains the candidate cell configuration information under a certain cell switching mechanism and forms an RRC reconfiguration signaling message based on the candidate cell configuration information, the first network device sends the second indication information together with the RRC reconfiguration signaling message to the terminal device. Since both the PDCCH instruction and the RRC reconfiguration signaling message are content required to perform validity management of the TA of the candidate cell, this method of carrying the first indication information in the PDCCH instruction and the second indication information in the RRC reconfiguration signaling message can also avoid resource waste caused by additional transmission.

[0227] In another example, the first indication information is carried in an RRC reconfiguration signaling message and the second indication information is carried in a PDCCH instruction. Specifically, when the first network device obtains the candidate cell configuration information under a certain cell switching mechanism and forms an RRC reconfiguration signaling message based on the candidate cell configuration information, the first network device sends the first indication information together with the RRC reconfiguration signaling message to the terminal device. When the terminal device sends a CFRA resource acquisition request to the first network device, the first network device sends the second indication information together with the PDCCH instruction to the terminal device. Similarly, since the PDCCH instruction and the RRC reconfiguration signaling message are both required to perform validity management of the TA of the candidate cell, this method of carrying the first indication information in the RRC reconfiguration signaling message and carrying the second indication information in the PDCCH instruction can also avoid resource waste caused by additional transmission.

[0228] It should be understood that the above-mentioned multiple ways of sending the first indication information and the second indication information enable the first network device to send the first indication information and the second indication information according to different sending ways, thereby improving the flexibility of sending the first indication information and the second indication information.

[0229] It should be understood that the first indication information and the second indication information can also be sent to the terminal device as the same independent signaling through the first network device. They can also be sent to the terminal device as independent signaling through the first network device respectively. The specific sending method is not limited in this application.

[0230] It should also be understood that when the first indication information and the second indication information are simultaneously carried in the PDCCH instruction or the RRC reconfiguration signaling message, the first indication information and the second indication information can also be carried as the same indication information in the PDCCH instruction or the RRC reconfiguration signaling message, and the specific form of the same indication information is not limited in this application.

[0231] It should be noted that after obtaining the TA of at least one candidate cell, if the terminal device determines based on the first indication information that the terminal device is to perform validity management on the TA of the candidate cell, then the validity management of the TA of the corresponding candidate cell is performed based on the TA of the at least one candidate cell obtained. If it is determined based on the first indication information that the first network device is to perform validity management on the TA of the candidate cell, third indication information is formed based on the TA of the at least one candidate cell and sent to the first network device. If it is determined based on the first indication information that the second network device is to perform validity management on the TA of the candidate cell, third indication information is similarly formed based on the TA of the at least one candidate cell and sent to the second network device. This allows both the first network device and the second network device to perform validity management on the TA of the candidate cell based on the third indication information.

[0232] It should also be noted that, based on the different carrying modes of the first indication information, when the terminal device triggers the CFRA process including RAR by itself, if the first indication information is carried in a PDCCH instruction or an RRC reconfiguration signaling message, the terminal device can trigger the CFRA process including RAR by itself based on the PDCCH instruction, or it can trigger the CFRA process including RAR by itself based on the RRC reconfiguration signaling message. If the first indication information is an independent signaling, the terminal device can trigger the CFRA process including RAR by itself based on the independent signaling, or it can trigger the CFRA process including RAR by itself based on the PDCCH instruction, or it can trigger the CFRA process including RAR by itself based on the RRC reconfiguration signaling message. This application does not limit this.

[0233] The following describes in detail a solution for managing the effectiveness of the timing advance TA of a candidate cell when the device for managing the effectiveness of the timing advance TA of the candidate cell is a terminal device, a first network device, or a second network device.

[0234] 1. The device that manages the validity of the timing advance TA of the candidate cell is the terminal device.

[0235] In the timing advance management method provided in the above embodiment, in addition to the terminal device receiving the first indication information sent by the first network device and obtaining the TA of the candidate cell, in order to enable the terminal device to manage the effectiveness of the TA of the candidate cell, it is also necessary to obtain relevant information for effectiveness management.

[0236] Then the relevant information for effectiveness management may include first configuration information and second configuration information.

[0237] Therefore, optionally, obtaining the first configuration information and the second configuration information may specifically include:

[0238] The first network device sends first configuration information and second configuration information to the terminal device.

[0239] The first configuration information is configuration information indicating that the candidate cell's TA is valid, and includes: information about the candidate cell's TA public validity duration and information about the TA becoming invalid if the public validity duration is exceeded, or information about the corresponding candidate cell's TA private validity duration and information about the corresponding TA becoming invalid if the private validity duration is exceeded. The second configuration information is configuration information indicating that the candidate cell's TA is updated within its validity period, and includes a TA public update duration threshold for the candidate cell or a TA private update duration threshold for the corresponding candidate cell.

[0240] The information included in the first configuration information and the second configuration information is introduced in detail below.

[0241] The common validity duration is a common duration set for the TAs of all candidate cells, during which the TAs of all candidate cells are valid. This setting method can reduce the fields occupied by the first configuration information and save transmission resources.

[0242] The private validity duration is the corresponding duration set for the TA of the corresponding candidate cell. The TA of the corresponding candidate cell is valid during the private validity duration. This setting method can make the corresponding duration of the TA of each candidate cell more adaptable to each candidate cell and improve the accuracy of the setting.

[0243] The public update duration threshold is a shared update duration threshold set for all candidate cell TAs based on the public validity duration set for all candidate cell TAs. The private update duration threshold is a corresponding update duration threshold set for each candidate cell TA based on the corresponding private validity duration set for each candidate cell TA.

[0244] Furthermore, the TA public update duration threshold of the candidate cell is a value less than the public effective duration or a value less than the remaining public effective duration, where the remaining public effective duration is the difference between the public effective duration and the timer when the TA timer is started. The TA private update duration threshold of the corresponding candidate cell is a value less than the private effective duration or a value less than the remaining private effective duration, where the remaining private effective duration is the difference between the private effective duration and the timer when the TA timer is started.

[0245] In order to more clearly illustrate the setting rules of the TA public update duration threshold of the candidate cell or the TA private update duration threshold of the candidate cell, an exemplary scenario is cited below for detailed description.

[0246] In one scenario, it is necessary to trigger a TA update for a candidate cell 10 milliseconds before the TA of the candidate cell becomes invalid. If the public valid duration of the TA of the candidate cell is set to 50 milliseconds, there are two ways to set the public update duration threshold.

[0247] First, set the TA public update time threshold of the candidate cell to a value less than the public valid time. For example, set the TA public update time threshold of the candidate cell to 40 milliseconds. Then, when the timer reaches 40 milliseconds, the TA update of the candidate cell is triggered.

[0248] Second, the TA public update duration threshold of the candidate cell is set to the value of the remaining public valid duration.

[0249] It should be understood that in this scenario, the remaining public validity duration is the difference between the candidate cell's TA public validity duration of 50 milliseconds and the elapsed time of 40 milliseconds, that is, 10 milliseconds. Therefore, if the candidate cell's TA public update duration threshold is set to 10 milliseconds, then when the timer reaches 40 milliseconds, the candidate cell's TA update is triggered.

[0250] It should be understood that the first configuration information and the second configuration information exist at the same time, and the terminal device can manage the effectiveness of the candidate cell TA based on the first configuration information and the second configuration information. Then, for different first configuration information and different second configuration information, the obtained combination of the first configuration information and the second configuration information can be any one of the following two combinations:

[0251] (1) The first configuration information includes the TA public valid duration of the candidate cell and the information that the TA is invalid when the public valid duration is exceeded. The second configuration information includes the TA public update duration threshold of the candidate cell.

[0252] (2) The first configuration information includes the TA private validity period of the corresponding candidate cell and the information that the TA is invalid when the private validity period is exceeded. The second configuration information includes the TA private update period threshold of the corresponding candidate cell.

[0253] The specific meanings for different combinations are as follows:

[0254] If the first configuration information includes the common valid duration of the TA of the candidate cells and the information that the TA becomes invalid when the common valid duration is exceeded, and the second configuration information includes the common update duration threshold of the TA of the candidate cells, it means that the TAs of the candidate cells have the same valid duration and the same update duration threshold.

[0255] Similarly, if the first configuration information includes the private validity duration of the TA corresponding to the candidate cell and the information that the corresponding TA becomes invalid after exceeding the private validity duration, and the second configuration information includes the private update duration threshold of the TA corresponding to the candidate cell, it means that the TAs of the candidate cells can have different validity durations and, on this basis, can have different update duration thresholds. Therefore, this embodiment provides the first configuration information and the second configuration information, and on this basis, proposes a combination of multiple first configuration information and second configuration information, so that the terminal device can manage the validity of the TA of the candidate cell based on the combination of multiple first configuration information and second configuration information, thereby improving the flexibility of terminal device management.

[0256] It should also be understood that when the first network device sends the first configuration information and the second configuration information to the terminal device, they can be sent together or separately, and the specific sending method is not limited in this application. The transmission method of the first configuration information and the second configuration information is described in detail below.

[0257] In one example, the first configuration information and the second configuration information can be carried in a physical downlink control channel scheduling PDCCH instruction. Specifically, when the terminal device sends a CFRA resource acquisition request to the first network device, the first network device sends the first configuration information and the second configuration information together with the PDCCH instruction to the terminal device. In this case, the first configuration information and the second configuration information can be predefined fields in the PDCCH instruction respectively. This method of carrying the first configuration information and the second configuration information in the PDCCH instruction can avoid resource waste caused by additional transmission.

[0258] In another example, the first configuration information and the second configuration information are carried in an RRC reconfiguration signaling message. Specifically, when the first network device obtains candidate cell configuration information under a certain cell handover mechanism and forms an RRC reconfiguration signaling message based on the candidate cell configuration information, the first network device sends the first configuration information and the second configuration information together with the RRC reconfiguration signaling message to the terminal device. In this case, the first configuration information and the second configuration information can each be a predefined field in the RRC reconfiguration signaling message. This method of carrying the first configuration information and the second configuration information simultaneously in the RRC reconfiguration signaling message can also avoid resource waste caused by additional transmission.

[0259] In another example, the first configuration information is carried in a PDCCH instruction and the second configuration information is carried in an RRC reconfiguration signaling message. Specifically, when the terminal device sends a CFRA resource acquisition request to the first network device, the first network device sends the first configuration information together with the PDCCH instruction to the terminal device. When the first network device obtains the candidate cell configuration information under a certain cell switching mechanism and forms an RRC reconfiguration signaling message based on the candidate cell configuration information, the first network device sends the second configuration information together with the RRC reconfiguration signaling message to the terminal device. Since both the PDCCH instruction and the RRC reconfiguration signaling message need to interact when performing cell switching, and the validity management of the TA of the candidate cell is also the content during cell switching, this method of carrying the first configuration information in the PDCCH instruction and the second configuration information in the RRC reconfiguration signaling message can also avoid the waste of resources caused by additional transmission.

[0260] In another example, the first configuration information is carried in an RRC reconfiguration signaling message and the second configuration information is carried in a PDCCH instruction. Specifically, when the first network device obtains the candidate cell configuration information under a certain cell switching mechanism and forms an RRC reconfiguration signaling message based on the candidate cell configuration information, the first network device sends the first configuration information together with the RRC reconfiguration signaling message to the terminal device. When the terminal device sends a CFRA resource acquisition request to the first network device, the first network device sends the second configuration information together with the PDCCH instruction to the terminal device. Similarly, since the PDCCH instruction and the RRC reconfiguration signaling message are both required to perform validity management of the TA of the candidate cell, this method of carrying the first configuration information in the RRC reconfiguration signaling message and carrying the second configuration information in the PDCCH instruction can also avoid resource waste caused by additional transmission.

[0261] It should be understood that the above-mentioned multiple ways of sending the first configuration information and the second configuration information enable the first network device to send the first configuration information and the second configuration information according to different sending ways, thereby improving the flexibility of transmitting the first configuration information and the second configuration information.

[0262] It should also be understood that the first configuration information and the second configuration information can also be sent to the terminal device via the first network device as the same independent signaling. Alternatively, they can be sent to the terminal device via the first network device as independent signaling, thereby improving the efficiency of parsing the first configuration information and the second configuration information. The specific sending method is not limited in this application.

[0263] It should also be understood that when the first configuration information and the second configuration information are simultaneously carried in the PDCCH instruction or the RRC reconfiguration signaling message, the first configuration information and the second configuration information can also be carried as the same indication information in the PDCCH instruction or the RRC reconfiguration signaling message. The specific form of the same indication information is not limited in this application.

[0264] Based on this, the terminal device performs validity management of the TA of the candidate cell based on the first configuration information and the second configuration information according to the first indication information, which may specifically include:

[0265] The TA timer of the candidate cell is started to count. If the counted time reaches the TA public update duration threshold or the TA private update duration threshold, the update of the TA of the corresponding candidate cell is triggered.

[0266] Since the first configuration information and the second configuration information have different combinations, in order to more clearly illustrate that the terminal device performs the validity management of the TA of the candidate cell based on the first configuration information and the second configuration information, the following takes the different combinations of the first configuration information and the second configuration information as an example to give a detailed introduction to the execution of the validity management of the TA of the candidate cell.

[0267] When the first configuration information includes the public effective duration of the TA of the candidate cell and the information that the TA becomes invalid when the public effective duration is exceeded, and the second configuration information includes the public update duration threshold of the TA of the candidate cell, the terminal device starts the TA timer of the candidate cell for timing when the public effective duration is not exceeded, and triggers the update of the TA of the corresponding candidate cell when the timing time reaches the TA public update duration threshold. Similarly, when the first configuration information includes the private effective duration of the TA of the corresponding candidate cell and the information that the TA becomes invalid when the private effective duration is exceeded, and the second configuration information includes the private update duration threshold of the TA of the corresponding candidate cell, the terminal device starts the TA timer of the candidate cell for timing when the private effective duration of the TA of the corresponding candidate cell is not exceeded, and triggers the update of the TA of the corresponding candidate cell when the timing time reaches the TA private update duration threshold of the corresponding candidate cell.

[0268] It is understandable that if the TA private validity duration and TA private update duration threshold of each candidate cell are different, then the time point for starting the TA timer of each candidate cell may be different, and the time point for triggering the update of the corresponding candidate cell TA may also be different. Therefore, this embodiment provides a detailed description of the effectiveness management of the TA of the candidate cell by the terminal device, and more specifically introduces the steps for the terminal device to manage the effectiveness of the TA of the candidate cell. Then, when the terminal device manages the effectiveness of the TA of the candidate cell, by sending the first configuration information and the second configuration information to the terminal device by the first network device, the terminal device can trigger the update of the candidate cell TA according to the two configuration information, and there is no need to trigger the update of the candidate cell TA when the candidate cell TA is about to expire, thereby improving the timeliness of the terminal device updating the candidate cell TA.

[0269] In this embodiment, when the update of the corresponding candidate cell TA is triggered, the following implementation methods may be included:

[0270] In one possible implementation, the terminal device sends a CFRA request to the second network device, instructing the second network device to obtain the current TA of the corresponding candidate cell. The second network device sends a CFRA response to the terminal device, including the current TA of the corresponding candidate cell. The terminal device updates the TA of the corresponding candidate cell based on the current TA.

[0271] Among them, the current TA of the candidate cell is the TA of the candidate cell most recently obtained by the terminal device.

[0272] It should be understood that in this implementation, the terminal device's transmission of a CFRA request to the second network device is premised on the terminal device having already acquired CFRA resources. The manner in which this acquisition of CFRA resources is performed is similar to the aforementioned method for acquiring CFRA resources and will not be further described here. Based on this, the terminal device sends a CFRA request to the first network device based on the CFRA resources. The second network device obtains the current TA of the candidate cell based on the CFRA request and includes the current TA of the candidate cell in the CFRA response, thereby transmitting the current TA of the candidate cell to the terminal device.

[0273] Then, based on the CFRA response, the terminal device can update the corresponding candidate cell TA according to the current TA. The specific updating method can be achieved by replacing the corresponding candidate cell TA with the current TA, which is not limited in this application. Therefore, in the above-mentioned method for triggering the update of the corresponding candidate cell TA, the terminal device can obtain the latest current TA according to the CFRA request by sending a CFRA request to the second network device, and can use the current TA to update the corresponding candidate cell TA, thereby successfully obtaining the current TA returned by the second network device. Compared with sending a new instruction to obtain the current TA, this saves transmission resources.

[0274] Another possible implementation manner is that the terminal device performs a current TA measurement process of the candidate cell and obtains the current TA of the candidate cell, thereby updating the TA of the corresponding candidate cell according to the current TA.

[0275] Among them, when the terminal device executes the current TA measurement process of the candidate cell, it can specifically receive signals from the first network device and the second network device at the same time, and record the receiving time corresponding to the signals received from the first network device and the second network device, and determine the difference between the two receiving times as the current TA of the candidate cell.

[0276] Based on this, the terminal device obtains the current TA of the candidate cell and uses the current TA to update the TA of the corresponding candidate cell. Therefore, in the above method of triggering the update of the TA of the corresponding candidate cell, the terminal device can update the TA of the corresponding candidate cell by measuring the latest current TA of the corresponding candidate cell, thereby improving the efficiency of obtaining the latest TA of the candidate cell.

[0277] It should be understood that the present application may use one of two methods to trigger the update of the candidate cell TA, thereby effectively improving the flexibility of updating the candidate cell TA when managed by the terminal device.

[0278] 2. The device that manages the validity of the timing advance TA of the candidate cell is the first network device.

[0279] In the timing advance management method provided in the above embodiment, in addition to receiving the third indication information sent by the terminal and knowing that the terminal device has obtained the TA of the corresponding candidate cell or receiving the TA value of the candidate cell sent by the terminal device, in order to enable the first network device to manage the validity of the TA of the candidate cell, it is also necessary to obtain relevant information for validity management.

[0280] Then the relevant information for effectiveness management may include first configuration information and second configuration information.

[0281] Therefore, optionally, obtaining the first configuration information and the second configuration information may specifically include:

[0282] The second network device sends the first configuration information and the second configuration information to the first network device.

[0283] It should be understood that the first configuration information and the second configuration information here are similar to the first configuration information and the second configuration information used when the terminal device manages the TA of the corresponding candidate cell, and will not be repeated here.

[0284] It should also be understood that according to the aforementioned method, since the first configuration information and the second configuration information have multiple combinations, the first network device can manage the effectiveness of the TA of the candidate cell based on the multiple combinations of the first configuration information and the second configuration information, thereby improving the management flexibility of the first network device.

[0285] It should also be understood that the first configuration information and the second configuration information can be carried in a separate signaling, thereby avoiding resource waste caused by additional transmission. Alternatively, the first configuration information can be carried in a separate signaling and the second configuration information can be carried in another separate signaling, thereby improving the efficiency of parsing the first configuration information and the second configuration information.

[0286] It should also be understood that the present application provides two methods for transmitting the first configuration information and the second configuration information, which can effectively improve the flexibility of transmitting the first configuration information and the second configuration information.

[0287] Based on this, the first network device manages the validity of the TA of the candidate cell based on the first configuration information and the second configuration information and according to the third indication information, which may specifically include:

[0288] The TA timer of the candidate cell is started to count. If the counted time reaches the TA public update duration threshold or the TA private update duration threshold, the update of the TA of the corresponding candidate cell is triggered.

[0289] In other words, when the first network device receives the third indication information sent by the terminal device, it determines to perform validity management on the candidate cell's TA. Based on this, the first network device, based on the first and second configuration information obtained, starts the candidate cell's TA timer for timing, if the public validity duration or the corresponding private validity duration indicated by the first configuration information has not been exceeded. When the timing reaches the TA public update duration threshold or the TA private update duration threshold indicated by the second configuration information, it triggers an update of the corresponding candidate cell's TA. Therefore, this embodiment provides a detailed description of the validity management of the candidate cell's TA by the first network device, and more specifically describes the steps for the first network device to perform validity management on the candidate cell's TA. When the first network device performs validity management on the candidate cell's TA, by having the second network device send the first and second configuration information to the first network device, the first network device can trigger an update of the candidate cell's TA based on the two configuration information, eliminating the need to trigger an update of the candidate cell's TA when the candidate cell's TA is about to expire, thereby improving the timeliness of the first network device's update of the candidate cell's TA.

[0290] In this embodiment, when the update of the corresponding candidate cell TA is triggered, the following implementation methods may be included:

[0291] In one possible implementation, the first network device sends a PDCCH instruction to the terminal device, where the PDCCH instruction includes random access resource indication information, where the random access resource indication information is used to instruct the terminal device to obtain the current TA of the corresponding candidate cell from the second network device through a CFRA request. The terminal device sends fourth indication information to the first network device, where the fourth indication information is used to indicate that the TA of the corresponding candidate cell or the updated TA value has been updated.

[0292] Among them, the fourth indication information is relevant information indicating that the terminal device has completed the TA update of the corresponding candidate cell.

[0293] It should be understood that in this implementation, when the first network device decides to trigger an update of the corresponding candidate cell TA, it sends a PDCCH instruction including random access resource indication information to the terminal device, so that after receiving the PDCCH instruction, the terminal device sends a CFRA request to the second network device based on the CFRA resource, thereby obtaining the current TA of the corresponding candidate cell and using the current TA to complete the update of the corresponding candidate cell TA. Based on this, after completing the update of the corresponding candidate cell TA, the terminal device forms fourth indication information based on the updated candidate cell TA and sends the fourth indication information to the first network device.

[0294] Then, when the terminal device forms the fourth indication information, the corresponding fourth indication information may be formed according to the combination of the first configuration information and the second configuration information:

[0295] If the combination of the first configuration information and the second configuration information is that the first configuration information includes the public TA validity period of the candidate cell and the information that the TA will be invalid if the public validity period is exceeded, and the second configuration information includes the public TA update period threshold of the candidate cell, indicating that the TA values ​​of the updated candidate cells are the same, then the fourth indication information is directly formed according to the TA value of the updated candidate cell or the TA of the updated candidate cell. If the combination of the first configuration information and the second configuration information is that the first configuration information includes the private TA validity period of the corresponding candidate cell and the information that the TA will be invalid if the private validity period is exceeded, and the second configuration information includes the private TA update period threshold of the corresponding candidate cell, indicating that there are different TA values ​​of the updated candidate cells, then the fourth indication information is formed according to the TA value of each updated candidate cell or the TA of each updated candidate cell.

[0296] In one example, when the terminal device forms the fourth indication information according to the TA value of each updated candidate cell, the TA value of each updated candidate cell can be associated with the corresponding candidate cell identifier, for example, a mapping relationship between the updated candidate cell TA value and its corresponding candidate cell identifier is established to form the fourth indication information according to the association result.

[0297] In another example, when the terminal device forms the fourth indication information according to the TA of each updated candidate cell, a string of specific fields may be formed based on the result of updating the TA of each candidate cell, and the specific fields corresponding to the candidate cell may be associated with the corresponding candidate cell identifier, for example, a mapping relationship may be established between the specific fields corresponding to the candidate cell and its corresponding candidate cell identifier, so as to form the fourth indication information according to the association result. The specific field indicates that the TA of the candidate cell has been updated.

[0298] It is understandable that the mapping relationship may be expressed in the form of a mapping table or other forms, which is not limited in this embodiment.

[0299] It should be understood that when there are multiple candidate cells, when forming the fourth indication information according to the updated TA values ​​of each candidate cell or the TA of each updated candidate cell, the fourth indication information can be formed according to the updated TA values ​​of all candidate cells. Alternatively, the fourth indication information can be formed according to the updated TA values ​​of all candidate cells. Alternatively, the fourth indication information can be formed according to the updated TA values ​​of a portion of candidate cells and the updated TA values ​​of another portion of candidate cells. The specific form of the fourth indication information is not limited in this application. Therefore, in the above-mentioned method of triggering the update of the corresponding candidate cell TA, the first network device sends a PDCCH instruction to the terminal device, so that the terminal device can send a CFRA request to the first network device based on the CFRA resource in the PDCCH instruction, and enables the terminal device to use the current TA to update the corresponding candidate cell TA after obtaining the latest current TA, so that the terminal device can send the update result to the first network device, thereby enabling the first network device to successfully obtain the latest TA of the candidate cell after the terminal device obtains the current TA returned by the second network device. Compared with obtaining the latest TA of the candidate cell after the terminal device sends a new instruction to obtain the current TA, transmission resources are saved and the timeliness of the first network device obtaining the latest TA of the candidate cell is improved.

[0300] Another possible implementation is that the first network device sends a measurement instruction to the terminal device, where the measurement instruction is used to instruct the terminal device to perform a current TA measurement process of the candidate cell. The terminal device sends fourth indication information to the first network device.

[0301] It should be understood that in this implementation, when the first network device decides to trigger an update of the corresponding candidate cell TA, it sends a measurement instruction to the terminal device, causing the terminal device to perform a current TA measurement process for the candidate cell according to the measurement instruction. Based on this, the terminal device updates the candidate cell TA based on the measured current TA, and forms fourth indication information based on the updated candidate cell TA, and sends the fourth indication information to the first network device.

[0302] It should also be understood that the manner in which the fourth indication information is formed here is similar to the manner in which the fourth indication information is formed in the previous implementation, and will not be repeated here. Therefore, in the above-mentioned method for triggering the update of the corresponding candidate cell TA, the first network device sends a measurement instruction to the terminal device, so that the terminal device can measure the latest current TA of the corresponding candidate cell by itself, and the terminal device can use the current TA to update the corresponding candidate cell TA, so that the terminal device can send the update result to the first network device. This enables the first network device to obtain the latest TA of the candidate cell after the terminal device obtains the current TA by itself, thereby improving the efficiency of the first network device in obtaining the latest TA of the candidate cell.

[0303] It should be understood that the present application may use one of two methods to trigger the update of the candidate cell TA, thereby effectively improving the flexibility of updating the candidate cell TA when managed by the first network device.

[0304] 3. The device that manages the validity of the timing advance TA of the candidate cell is the second network device.

[0305] In the timing advance management method provided in the above embodiment, in addition to receiving the third indication information sent by the terminal and knowing that the terminal device has obtained the TA of the corresponding candidate cell or receiving the TA value of the candidate cell sent by the terminal device, in order to enable the second network device to manage the validity of the TA of the candidate cell, it is also necessary to obtain relevant information for validity management.

[0306] Then the relevant information for effectiveness management may include first configuration information and second configuration information.

[0307] Based on this, the second network device obtains the first configuration information and the second configuration information corresponding to the candidate cell.

[0308] It should be understood that the first configuration information and the second configuration information here are similar to the first configuration information and the second configuration information used when the terminal device or the first network device manages the TA of the corresponding candidate cell, and will not be repeated here.

[0309] It should also be understood that, as in the aforementioned method, the first configuration information and the second configuration information have multiple combinations, and the second network device can manage the effectiveness of the TA of the candidate cell based on the multiple combinations of the first configuration information and the second configuration information, thereby improving the flexibility of the management of the second network device.

[0310] Afterwards, the first network device performs validity management on the TA of the candidate cell based on the first configuration information and the second configuration information and according to the third indication information, which may specifically include:

[0311] The TA timer is started to count. If the counted time reaches the TA public update duration threshold or the TA private update duration threshold, the update of the corresponding candidate cell TA is triggered.

[0312] In other words, when the second network device receives the third indication information sent by the terminal device, it determines to perform validity management on the candidate cell's TA. Based on this, the second network device obtains the first and second configuration information corresponding to the controlled candidate cell, and starts the corresponding candidate cell's TA timer for timing if the public validity duration or the corresponding private validity duration indicated by the first configuration information has not exceeded. When the timing reaches the TA public update duration threshold or the TA private update duration threshold indicated by the second configuration information, it triggers an update of the corresponding candidate cell's TA. Therefore, this embodiment provides a detailed description of the second network device's performance of validity management on the candidate cell's TA, and more specifically describes the steps for the second network device to perform validity management on the candidate cell's TA. Therefore, when the second network device performs validity management on the candidate cell's TA, by obtaining the first and second configuration information, the second network device can trigger an update of the candidate cell's TA based on the two configuration information, eliminating the need to trigger an update of the candidate cell's TA when the candidate cell's TA is about to expire, thereby improving the timeliness of the second network device's updates to the candidate cell's TA.

[0313] In this embodiment, when the update of the corresponding candidate cell TA is triggered, the following implementation methods may be included:

[0314] In one possible implementation, the second network device sends a first message to the first network device, the first message being used to instruct the first network device to send a PDCCH instruction to the terminal device. The terminal device sends a CFRA request to the second network device, the CFRA request being used to instruct the second network device to obtain the current TA of the corresponding candidate cell. The second network device sends a CFRA response to the terminal device, the CFRA response including the current TA of the corresponding candidate cell. The terminal device sends fourth indication information to the second network device, the fourth indication information being used to indicate that the TA of the corresponding candidate cell or the updated TA value has been updated.

[0315] The first message is an indication message indicating that a PDCCH instruction is sent to a terminal device. For example, the first message may be an indication message including an identifier, index, or number indicating "sending a PDCCH instruction to a terminal device," or may be a field indicating "sending a PDCCH instruction to a terminal device." This application does not limit the specific form of the first message.

[0316] It should be understood that in this implementation, when the second network device decides to trigger an update of the TA of the corresponding candidate cell, it sends a first message to the first network device, causing the first network device to send a PDCCH instruction to the terminal device according to the content indicated by the first message, and then causing the terminal device to send a CFRA request to the second network device based on the CFRA resource in the PDCCH instruction. Then, after receiving the CFRA request, the second network device obtains the current TA of the controlled candidate cell and carries it in the CFRA response to send the current TA of the candidate cell to the terminal device.

[0317] Based on this, the terminal device obtains the current TA of the candidate cell through the CFRA response, and uses the current TA to update the TA of the corresponding candidate cell, and forms fourth indication information based on the updated TA of the candidate cell, and sends it to the second network device. Therefore, in the above-mentioned method for triggering the update of the corresponding candidate cell TA, the second network device sends a first message to the first network device, so that the first network device can send a PDCCH instruction to the terminal device according to the first message, and the terminal device can send a CFRA request to the first network device based on the CFRA resource in the PDCCH instruction, so that the terminal device can use the current TA to update the corresponding candidate cell TA after obtaining the latest current TA, and then the terminal device can send the update result to the second network device, thereby enabling the second network device to successfully obtain the latest TA of the candidate cell after the terminal device obtains the returned current TA. Compared with obtaining the latest TA of the candidate cell after the terminal device sends a new instruction to obtain the current TA, transmission resources are saved and the timeliness of the second network device obtaining the latest TA of the candidate cell is improved.

[0318] Another possible implementation is that the second network device sends a second message to the first network device, where the second message is used to instruct the first network device to send a measurement instruction to the terminal device. The terminal device sends fourth instruction information to the second network device.

[0319] The second message is an instruction message indicating that a measurement instruction is being sent to a terminal device. For example, the second message may include an identifier, index, or number indicating "sending a measurement instruction to a terminal device," or may include a field indicating "sending a measurement instruction to a terminal device." This application does not limit the specific form of the second message.

[0320] It should be understood that in this implementation, when the second network device decides to trigger an update of the TA of the corresponding candidate cell, it sends a second message to the first network device, causing the first network device to send a measurement instruction to the terminal device based on the second message, thereby causing the terminal device to perform a current TA measurement process for the candidate cell based on the measurement instruction. Based on this, the terminal device updates the TA of the candidate cell based on the measured current TA, and forms fourth indication information based on the updated candidate cell TA, and sends the fourth indication information to the first network device. Therefore, in the above-mentioned method for triggering an update of the TA of the corresponding candidate cell, the second network device sends the second message to the first network device, causing the first network device to send a measurement instruction to the terminal device based on the second message, and allowing the terminal device to independently measure the latest current TA of the corresponding candidate cell, thereby allowing the terminal device to use the current TA to update the TA of the corresponding candidate cell, and then allowing the terminal device to send the update result to the second network device. This enables the second network device to obtain the latest TA of the candidate cell after the terminal device obtains the current TA on its own, thereby improving the efficiency of the second network device in obtaining the latest TA of the candidate cell.

[0321] It should be understood that the present application may use one of two methods to trigger the update of the candidate cell TA, thereby effectively improving the flexibility of updating the candidate cell TA when managed by the second network device.

[0322] In the method of the present application, the purpose of managing the validity of the candidate cell's TA is to enable the terminal device to perform handover to the target cell according to the valid target cell's TA. Therefore, the method of performing handover to the target cell according to the valid target cell's TA is described.

[0323] First, the first network device sends a third message to the second network device, where the third message is used to indicate whether the target cell TA managed by the second network device is valid. The second network device then sends a fourth message to the first network device, where the fourth message includes information about whether the target cell TA is valid. This information about whether the target cell TA is valid is used to indicate whether the MAC CE signaling sent by the first network device to the terminal device includes the target cell TA value.

[0324] Among them, the third message is an indication message indicating whether the managed target cell TA is valid. The fourth message is indication information indicating whether the target cell TA is valid. For example, the third message can be an indication message such as an identifier, index, or number indicating whether the managed target cell TA is valid, or a field indicating whether the managed target cell TA is valid. The fourth message can be an indication message such as an identifier, index, or number indicating whether the managed target cell TA is valid or invalid, or a field indicating whether the managed target cell TA is valid or invalid. This application does not limit the specific form of the third and fourth messages.

[0325] It should be understood that the prerequisite for the terminal device to perform handover to the target cell based on the valid target cell's TA is to receive MAC CE signaling sent by the first network device. Therefore, the first network device sends a third message to the second network device, so that the second network device determines whether the TA of the controlled target cell is valid based on the third message, and forms a fourth message based on the validity result to inform the first network device of the validity of the target cell's TA. Therefore, by receiving the instruction sent by the first network device to determine the validity of the target cell's TA, the second network device can promptly learn the validity of the target cell's TA and promptly inform the first network device of the validity of the target cell's TA.

[0326] Then, after the first network device determines whether the target cell TA is valid according to the fourth message, the following two situations may occur:

[0327] One possible scenario is that if the first network device determines that there is a valid target cell TA, the first network device carries the target cell TA value in the MAC CE signaling and sends a MAC CE signaling to the terminal device. The MAC CE signaling is used to instruct the terminal device to send a switching indication to the second network device corresponding to the target cell.

[0328] It should be understood that when a valid target cell TA exists, the terminal device can directly perform a handover to the target cell based on the valid target cell TA. Therefore, when the first network device determines that a valid target cell TA exists, it carries the target cell TA value in the MAC CE signaling to instruct the terminal device to send a handover indication to the second network device corresponding to the target cell.

[0329] Another possible scenario is that if the first network device determines that there is no valid target cell TA, the first network device does not carry the target cell TA value in the MAC CE signaling, and sends a MAC CE signaling to the terminal device. The MAC CE signaling is used to instruct the terminal device to perform an uplink synchronization process with the second network device corresponding to the target cell.

[0330] It should be understood that when the terminal device determines that there is no valid target cell TA, the terminal device cannot perform handover and needs to determine the TA of the target cell again. Therefore, when the first network device determines that there is no valid target cell TA, it does not carry the target cell TA value in the MAC CE signaling to instruct the terminal device to perform an uplink synchronization process with the second network device corresponding to the target cell, thereby re-determining the TA of the target cell. Therefore, by knowing the result of the validity of the target cell TA, the first network device can carry the target cell TA value in the MAC CE signaling when it is determined to be valid, thereby instructing the terminal device to initiate handover. And when it is determined to be invalid, the target cell TA value can be not carried in the MAC CE signaling, thereby instructing the terminal device to perform an uplink synchronization process with the target cell, thereby improving the accuracy of the instruction.

[0331] Based on this, the terminal device determines the subsequent actions to be performed according to the MAC CE signaling.

[0332] It should be noted that, since the terminal device can directly learn whether the target cell's TA is valid or invalid when the terminal device manages the validity of the candidate cell's TA, and the time when the terminal device learns is after the time when the first network device learns. Therefore, if the current management situation is that the terminal device manages the validity of the candidate cell's TA, the terminal device determines the subsequent actions to be performed based on the MAC CE signaling, which may include:

[0333] If the terminal device determines that there is a valid target cell TA, it directly sends a handover instruction to the second network device corresponding to the target cell, where the handover instruction is used to instruct handover to the target cell. If the terminal device determines that there is no valid target cell TA, it further determines whether the MAC CE signaling includes the target cell TA value, and sends a handover instruction to the second network device corresponding to the target cell if it is determined that the MAC CE signaling includes the target cell TA value. If it is determined that the MAC CE signaling does not include the target cell TA value, it performs an uplink synchronization process with the target cell based on the result that the target cell TA is invalid.

[0334] It should be noted that the terminal device can determine whether there is a valid target cell TA based on the TA timer corresponding to the target cell. Specifically, when the TA timer corresponding to the target cell has not timed out, it is determined that there is a valid target cell TA. When the TA timer corresponding to the target cell has timed out, it is determined that there is no valid target cell TA.

[0335] It should be understood that there are two situations corresponding to the TA timer corresponding to the target cell not timing out:

[0336] (1) The TA of the target cell has not been updated and the timing duration does not exceed the public validity duration or private validity duration of the TA of the target cell.

[0337] (2) The TA of the target cell has been updated and the TA timer corresponding to the target cell has been restarted. After the restart, the TA of the target cell has not been updated and the timer duration exceeds the public validity period or private validity period of the TA of the target cell.

[0338] It should also be understood that the above description of the situation where the TA timer corresponding to the target cell has not timed out is only an example and should not constitute any limitation to this application.

[0339] It should also be understood that when a terminal device instructs handover to a target cell, indicating that the target cell TA is valid, an indication can be directly sent to the target cell to implement handover. This indication can be an RRC reconfiguration signaling complete message or any uplink data, and the specific content of the indication is not limited in this application. When the terminal device performs an uplink synchronization process with the target cell and indicates that the target cell TA is invalid, a CFRA request can be sent to the second network device to reacquire the target cell TA to implement uplink synchronization. This CFRA request can include a target cell identifier, which can be any identifier representing the identity of the target cell, such as the name or number of the target cell, and is not limited in this application. Therefore, when the terminal device manages candidate cell TAs, by confirming whether a valid target cell TA currently exists, the terminal device can directly initiate handover to the target cell if it determines that the target cell TA exists. If it determines that the target cell TA does not exist, the terminal device can further determine whether the MAC CE signaling includes the target cell TA value, thereby directly initiating handover to the target cell if it determines that the target cell TA is included, and performing uplink synchronization with the target cell if it determines that the target cell TA is not included, thereby improving the success rate of handover.

[0340] If the current management situation is that the first network device or the second network device manages the validity of the TA of the candidate cell, the terminal device determines the subsequent actions to be performed according to the MAC CE signaling, which may specifically include:

[0341] If the terminal device determines that the MAC CE signaling includes the target cell's TA value, it directly sends a handover instruction to the second network device corresponding to the target cell. If the terminal device determines that the MAC CE signaling does not include the target cell's TA value, it performs an uplink synchronization process with the target cell, including CFRA. Therefore, when the first network device or the second network device manages the candidate cell's TA, the terminal device can determine whether the MAC CE signaling includes the target cell's TA value. If it is determined that the target cell's TA value is included, it can directly initiate a handover to the target cell. If it is determined that the target cell's TA value is not included, it can perform an uplink synchronization process with the target cell, further improving the success rate of the handover.

[0342] The following describes in detail a scheme for managing the effectiveness of the timing advance TA of a candidate cell when the devices for managing the effectiveness of the timing advance TA of the candidate cell are a terminal device, a first network device, and a second network device in the form of a signaling interaction diagram.

[0343] FIG4 is a diagram of signaling interactions between a terminal device and various network devices when the terminal device manages the timing advance according to an embodiment of the present application.

[0344] Taking LTM switching as an example, first, the terminal device in the network connection state sends the measurement results to the first network device. The first network device decides to perform LTM switching based on the measurement results and the terminal device's support capability for LTM switching, and sends an LTM switching request to the second network device. The LTM switching request is used to instruct the second network device to obtain candidate cell configuration information. The second network device sends the candidate cell configuration information to the first network device. The first network device carries the candidate cell configuration information in the RRC reconfiguration signaling message and sends the RRC reconfiguration signaling message to the terminal device. And,

[0345] S401. A first network device sends a PDCCH instruction to a terminal device, where the PDCCH instruction includes a CFRA resource.

[0346] It should be understood that in addition to the RRC reconfiguration signaling message and the PDCCH instruction, the first network device also needs to send the first indication information, or the first indication information and the second indication information to the terminal device.

[0347] It should also be understood that according to the aforementioned method, the first indication information and the second indication information can be carried together in the RRC reconfiguration signaling message and sent to the terminal device, or can be carried together in the PDCCH instruction and sent to the terminal device, or can be sent together as an independent signaling to the terminal device, or can be carried separately in the RRC reconfiguration signaling message or PDCCH instruction or independent signaling and sent to the terminal device. This application does not limit this.

[0348] It should also be understood that when the first network device sends only the first indication information to the terminal device, the terminal device triggers the CFRA request with RAR on its own. When the first network device sends the first indication information and the second indication information to the terminal device, the terminal device triggers the CFRA request with RAR based on the second indication information. For the sake of simplicity, the figure only shows the case where the first network device carries the first indication information and the second indication information together in a PDCCH instruction and sends the PDCCH instruction to the terminal device, so that the terminal device triggers the CFRA request with RAR based on the second indication information.

[0349] S402: The terminal device sends a CFRA request with RAR to a second network device. The second network device is a candidate cell network device. The candidate cells include a target cell and a potential target cell. There are one or more candidate cells.

[0350] S403: The second network device sends a CFRA response with RAR to the terminal device.

[0351] S404. Before the TA of the candidate cell expires, the terminal device starts the TA timer of the candidate cell.

[0352] It should be understood that when instructing the terminal device to manage the timing advance, in addition to the RRC reconfiguration signaling message, PDCCH instruction, first indication information, and second indication information, the first network device also needs to send the first configuration information and the second configuration information to the terminal device before the terminal device starts the TA timer of the candidate cell.

[0353] It should also be understood that, according to the aforementioned method, the transmission method of the first configuration information and the second configuration information is similar to the transmission method of the first indication information and the second indication information, and will not be further described here. In addition, for the sake of simplicity, the figure only shows the case where the first configuration information and the second configuration information are carried together in the PDCCH instruction.

[0354] S405. The terminal device triggers an update of the candidate cell TA when determining that the update condition is currently met based on the first configuration information and the second configuration information.

[0355] S406. The terminal device sends the L1 measurement result to the first network device.

[0356] S407: The first network device sends an LTM switching command to the terminal device.

[0357] It should be understood that the LTM switching command includes MAC CE signaling.

[0358] S408: The terminal device disconnects from the first network device.

[0359] S409: The terminal device determines whether to initiate an uplink synchronization process with CFRA or directly switch based on whether there is a valid target cell TA.

[0360] It should be understood that when the target cell TA is valid, the terminal device directly initiates a handover to the target cell. When the target cell TA is invalid, the terminal device initiates an uplink synchronization process with CFRA to the target cell, thereby re-acquiring the target cell TA and initiating a handover to the target cell based on the TA.

[0361] S410: The terminal device completes LTM switching for the target cell.

[0362] It should be noted that the specific implementation scheme of the terminal device managing the timing advance in this embodiment is similar to the specific implementation scheme of the terminal device managing the effectiveness of the TA of the candidate cell in the above embodiment, and will not be repeated here.

[0363] FIG5 is a diagram of signaling interactions between a terminal device and each network device when the timing advance is managed by the first network device according to an embodiment of the present application.

[0364] Taking LTM switching as an example, as mentioned above, the terminal device in the network connection state sends the measurement results to the first network device. The first network device decides to perform LTM switching based on the measurement results and the terminal device's support capability for LTM switching, and sends an LTM switching request to the second network device. The LTM switching request is used to instruct the second network device to obtain candidate cell configuration information. The second network device sends the candidate cell configuration information to the first network device. The first network device carries the candidate cell configuration information in the RRC reconfiguration signaling message and sends the RRC reconfiguration signaling message to the terminal device. And,

[0365] S501. A first network device sends a PDCCH instruction to a terminal device, where the PDCCH instruction includes a CFRA resource.

[0366] As before, in addition to the RRC reconfiguration signaling message and the PDCCH instruction, the first network device also needs to send the first indication information, or the first indication information and the second indication information to the terminal device.

[0367] As before, according to the aforementioned method, the first indication information and the second indication information can be carried together in the RRC reconfiguration signaling message and sent to the terminal device, or can be carried together in the PDCCH instruction and sent to the terminal device, or can be sent together as an independent signaling to the terminal device, or can be carried separately in the RRC reconfiguration signaling message or PDCCH instruction or independent signaling and sent to the terminal device. This application does not limit this.

[0368] As before, when the first network device sends only the first indication information to the terminal device, the terminal device triggers a CFRA request with RAR on its own. When the first network device sends the first indication information and the second indication information to the terminal device, the terminal device triggers a CFRA request with RAR based on the second indication information. For the sake of simplicity, the figure only shows the case where the first network device carries the first indication information and the second indication information together in a PDCCH instruction and sends the PDCCH instruction to the terminal device, causing the terminal device to trigger a CFRA request with RAR based on the second indication information.

[0369] S502: The terminal device sends a CFRA request with RAR to a second network device. The second network device is a candidate cell network device. The candidate cells include a target cell and a potential target cell. There are one or more candidate cells.

[0370] S503: The second network device sends a CFRA response with RAR to the terminal device.

[0371] S504. The terminal device sends third indication information to the first network device, where the third indication information is used to indicate that the candidate cell TA or the TA value of the candidate cell has been obtained.

[0372] S505: Before the TA of the candidate cell expires, the first network device starts the TA timer of the candidate cell.

[0373] It should be understood that when instructing the first network device to manage the timing advance, the second network device also needs to send the first configuration information and the second configuration information to the first network device before the first network device starts the TA timer of the candidate cell.

[0374] It should also be understood that, according to the aforementioned method, the first configuration information and the second configuration information can be sent to the first network device as a separate signaling message, or can be sent to the first network device as separate signaling messages, and this application does not limit this. Furthermore, for the sake of simplicity, the figure only illustrates the case where the first configuration information and the second configuration information are sent as a separate signaling message.

[0375] S506. When the first network device determines that the update condition is currently met according to the first configuration information and the second configuration information, it sends a PDCCH instruction to the terminal device.

[0376] S507. The terminal device triggers the update of the candidate cell TA.

[0377] S508. The terminal device sends the L1 measurement result to the first network device.

[0378] S509: The first network device sends an LTM switching command to the terminal device.

[0379] It should be understood that the LTM switching command includes MAC CE signaling.

[0380] S510: The terminal device disconnects from the first network device.

[0381] S511. The terminal device determines whether to initiate an uplink synchronization process with CFRA or directly switch based on whether there is a valid target cell TA.

[0382] As before, when the target cell's TA is valid, the terminal device directly initiates a handover to the target cell. When the target cell's TA is invalid, the terminal device initiates an uplink synchronization process with CFRA to the target cell, thereby re-acquiring the target cell's TA and initiating a handover to the target cell based on the TA.

[0383] S512: The terminal device completes LTM switching for the target cell.

[0384] It should be noted that the specific implementation scheme of the first network device managing the timing advance in this embodiment is similar to the specific implementation scheme of the first network device managing the effectiveness of the TA of the candidate cell in the above embodiment, and will not be repeated here.

[0385] FIG6 is a diagram of signaling interactions between a terminal device and each network device when the timing advance is managed by the second network device according to an embodiment of the present application.

[0386] Taking LTM switching as an example, as mentioned above, the terminal device in the network connection state sends the measurement results to the first network device. The first network device decides to perform LTM switching based on the measurement results and the terminal device's support capability for LTM switching, and sends an LTM switching request to the second network device. The LTM switching request is used to instruct the second network device to obtain candidate cell configuration information. The second network device sends the candidate cell configuration information to the first network device. The first network device carries the candidate cell configuration information in the RRC reconfiguration signaling message and sends the RRC reconfiguration signaling message to the terminal device. And,

[0387] S601. A first network device sends a PDCCH instruction to a terminal device, where the PDCCH instruction includes a CFRA resource.

[0388] As before, in addition to the RRC reconfiguration signaling message and the PDCCH instruction, the first network device also needs to send the first indication information, or the first indication information and the second indication information to the terminal device.

[0389] As before, according to the aforementioned method, the first indication information and the second indication information can be carried together in the RRC reconfiguration signaling message and sent to the terminal device, or can be carried together in the PDCCH instruction and sent to the terminal device, or can be sent together as an independent signaling to the terminal device, or can be carried separately in the RRC reconfiguration signaling message or PDCCH instruction or independent signaling and sent to the terminal device. This application does not limit this.

[0390] It should also be understood that when the first network device sends only the first indication information to the terminal device, the terminal device triggers the CFRA request with RAR on its own. When the first network device sends the first indication information and the second indication information to the terminal device, the terminal device triggers the CFRA request with RAR based on the second indication information. For the sake of simplicity, the figure only shows the case where the first network device carries the first indication information and the second indication information together in a PDCCH instruction and sends the PDCCH instruction to the terminal device, so that the terminal device triggers the CFRA request with RAR based on the second indication information.

[0391] S602: The terminal device sends a CFRA request with RAR to a second network device. The second network device is a candidate cell network device. The candidate cells include a target cell and a potential target cell. There are one or more candidate cells.

[0392] S603: The second network device sends a CFRA response with RAR to the terminal device.

[0393] S604. The terminal device sends third indication information to the second network device, where the third indication information is used to indicate that the candidate cell TA or the TA value of the candidate cell has been obtained.

[0394] S605: Before the TA of the candidate cell expires, the second network device starts the TA timer of the candidate cell.

[0395] It should be understood that when the first network device is instructed to manage the timing advance, the second network device also needs to obtain the first configuration information and the second configuration information before starting the TA timer of the candidate cell.

[0396] S606: When determining that the update condition is currently met, the second network device sends random access procedure indication information to the first network device.

[0397] S607. The first network device sends a PDCCH instruction to the terminal device according to the random access procedure indication information.

[0398] S608. The terminal device triggers the update of the candidate cell TA.

[0399] S609. The terminal device sends the L1 measurement result to the first network device.

[0400] S610: The first network device sends an LTM switching command to the terminal device.

[0401] It should be understood that the LTM switching command includes MAC CE signaling.

[0402] S611: The terminal device disconnects from the first network device.

[0403] S612: The terminal device determines whether to initiate an uplink synchronization process with CFRA or directly switch based on whether there is a valid target cell TA.

[0404] As before, when the target cell's TA is valid, the terminal device directly initiates a handover to the target cell. When the target cell's TA is invalid, the terminal device initiates an uplink synchronization process with CFRA to the target cell, thereby re-acquiring the target cell's TA and initiating a handover to the target cell based on the TA.

[0405] S613: The terminal device completes LTM switching for the target cell.

[0406] It should be noted that the specific implementation scheme of the second network device managing the timing advance in this embodiment is similar to the specific implementation scheme of the second network device managing the effectiveness of the TA of the candidate cell in the above embodiment, and will not be repeated here.

[0407] The method provided by the embodiment of the present application is described in detail above with reference to Figures 2 to 6. The device provided by the embodiment of the present application is described in detail below with reference to Figure 7.

[0408] FIG7 is a schematic block diagram of a timing advance management device 70 provided in an embodiment of the present application. As shown in FIG7 , the timing advance management device 70 may include a processing unit 71 and a transceiver unit 72 .

[0409] In one possible design, the timing advance management device 70 can implement the operations corresponding to the terminal device in the above method embodiment. For example, the timing advance management device can be a terminal device, or a component configured in the terminal device, such as a chip or circuit.

[0410] The timing advance management device 70 can implement the corresponding operations of the terminal device in the method embodiments shown in Figures 2 to 6. For example, the transceiver unit 72 can be used to execute step 201 in method 200, and the processing unit 71 can be used to execute steps 202 to 204 in method 200. Furthermore, the various units in the timing advance management device 70 and the other operations and / or functions described above are respectively used to implement the corresponding processes in the method embodiment shown in Figure 2.

[0411] Specifically, when the timing advance management apparatus 70 is used to execute the method 200 in FIG. 2 , the transceiver unit 72 may be configured to receive first indication information sent by a first network device, the first indication information being used to indicate a device that manages the validity of the timing advance (TA) of a candidate cell, the device being a terminal device, a first network device, or a second network device, and the candidate cell being one or more. The processing unit 71 may be configured to manage the validity of the TA of the candidate cell according to the first indication information if the device managing the validity of the TA of the candidate cell is a terminal device, and may also be configured to send third indication information to the first network device if the device managing the validity of the TA of the candidate cell is the first network device, the third indication information being used to indicate that the TA or TA value of the corresponding candidate cell has been obtained, and may also be configured to send the third indication information to the second network device if the device managing the validity of the TA of the candidate cell is the second network device. The transceiver unit 72 may also be configured to communicate with the first network device and the second network device. The first network device is the network device to which the source cell belongs, and the second network device is the network device to which the candidate cell belongs.

[0412] In another possible design, the timing advance management device 70 can implement the operations corresponding to the first network device in the above method embodiment. For example, the timing advance management device can be the first network device, or a component configured in the first network device, such as a chip or circuit.

[0413] The timing advance management device 70 can implement the corresponding operations of the first network device in the method embodiment shown in Figure 2. For example, the transceiver unit 72 can be used to execute step 201 in method 200, and the processing unit 71 can be used to execute step 203 in method 200. Furthermore, the various units in the timing advance management device 70 and the other operations and / or functions described above are respectively used to implement the corresponding processes in the method embodiment shown in Figure 2.

[0414] Specifically, when the timing advance management apparatus 70 is used to execute the method 200 in FIG. 2 , the transceiver unit 72 may be configured to send first indication information to a terminal device, where the first indication information is used to indicate a device that manages the validity of the timing advance TA of a candidate cell, where the device that manages the validity of the timing advance TA of the candidate cell is the terminal device, the first network device, or the second network device, and the candidate cell is one or more. The processing unit 71 may be configured to enable the first network device to manage the validity of the TA of the candidate cell based on the third indication information, where the third indication information is used to indicate that the TA or TA value of the corresponding candidate cell has been obtained.

[0415] In another possible design, the timing advance management device 70 can implement the operations corresponding to the second network device in the above method embodiment. For example, the timing advance management device can be the second network device, or a component configured in the second network device, such as a chip or circuit.

[0416] The timing advance management device 70 can implement the corresponding operations of the second network device in the method embodiment shown in Figure 2. For example, the processing unit 71 can be used to execute step 204 in method 200. Furthermore, the various units in the timing advance management device 70 and the other operations and / or functions described above are respectively for implementing the corresponding processes in the method embodiment shown in Figure 2.

[0417] Specifically, when the timing advance management device 70 is used to execute the method 200 in Figure 2, the processing unit 71 can be used by the second network device to manage the validity of the TA of the candidate cell according to the third indication information, and the third indication information is used to indicate that the TA or TA value of the corresponding candidate cell has been obtained.

[0418] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0419] It should also be understood that the division of modules in the embodiments of the present application is illustrative and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the present application may be integrated into a single processor, or may exist physically separately, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or software functional modules.

[0420] It should be understood that the timing advance management device 70 may correspond to the terminal device 1001, the first network device 1002, or the second network device 1003 in the communication system 1000 shown in Figure 1. The terminal device 1001 may be an example of a terminal device, and the first network device 1002 may be an example of a first network device. The second network device 1003 may be an example of a second network device. The processing unit 71 in the timing advance management device 70 may correspond to a processor in the terminal device 1001, the first network device 1002, or the second network device 1003. The processor in the terminal device 1001, the first network device 1002, or the second network device 1003 may call instructions stored in the memory to implement the aforementioned functions, such as network coding and obtaining original packets. The transceiver unit 72 may correspond to an interface in the terminal device 1001, the first network device 1002, or the second network device 1003. The transceiver unit 72 may respond to instructions from the processor to implement the aforementioned functions of receiving and / or transmitting data.

[0421] Specifically, the transceiver unit 72 in the timing advance management device 70 can be implemented by a transceiver or a communication interface, and for example, can correspond to the transceiver 8002 in the terminal device 8000 shown in FIG8 and the transceiver 9002 in the network device 9000 shown in FIG9 . The processing unit 71 in the timing advance management device 70 can be implemented by at least one processor, and for example, can correspond to the processor 8001 in the terminal device 8000 shown in FIG8 and the processor 9006 in the network device 9000 shown in FIG9 . The network device can be a first network device or a second network device.

[0422] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0423] Figure 8 is a possible structural diagram of a terminal device 8000 provided in an embodiment of the present application. The terminal device 8000 can be applied to the system shown in Figure 1 to perform the functions of the terminal device in the above method embodiment. As shown in Figure 8, the terminal device 8000 includes a processor 8001 and a transceiver 8002. Optionally, the terminal device 8000 also includes a memory 8003. The processor 8001, the transceiver 8002 and the memory 8003 can communicate with each other through an internal connection path to transmit control and / or data signals. The memory 8003 is used to store computer programs, and the processor 8001 is used to call and run the computer program from the memory 8003 to control the transceiver 8002 to send and receive signals. Optionally, the terminal device 8000 may also include an antenna 8004 for sending the uplink data or uplink control signaling output by the transceiver 8002 via a wireless signal.

[0424] The processor 8001 and the memory 8003 may be combined into a processing device, and the processor 8001 is configured to execute program code stored in the memory 8003 to implement the aforementioned functions. In a specific implementation, the memory 8003 may also be integrated into the processor 8001 or independent of the processor 8001. The processor 8001 may correspond to the processing unit 71 in FIG. 7 .

[0425] The transceiver 8002 may correspond to the transceiver unit 72 in FIG7 . The transceiver 8002 may include a receiver (or receiver, receiving circuit) and a transmitter (or transmitter, transmitting circuit). The receiver is used to receive signals, and the transmitter is used to transmit signals.

[0426] It should be understood that the terminal device 8000 shown in FIG8 is capable of implementing the various processes involved in the terminal device in the method embodiments shown in FIG2 through FIG6 . The operations and / or functions of the various modules in the terminal device 8000 are respectively for implementing the corresponding processes in the above-mentioned method embodiments. For details, please refer to the description of the above-mentioned method embodiments; to avoid repetition, detailed descriptions are omitted here.

[0427] The processor 8001 can be used to execute the actions implemented within the terminal device described in the previous method embodiments, while the transceiver 8002 can be used to execute the actions of the terminal device sending to or receiving from the network device described in the previous method embodiments. For details, please refer to the description of the previous method embodiments and will not be repeated here.

[0428] Optionally, the terminal device 8000 may further include a power supply 8005 for providing power to various devices or circuits in the terminal device.

[0429] In addition, in order to make the functions of the terminal device more complete, the terminal device 8000 can also include one or more of an input unit 8006, a display unit 8007, an audio circuit 8008, a camera 8009 and a sensor 8010, and the audio circuit can also include a speaker 8011, a microphone 8012, etc.

[0430] Figure 9 is a possible structural diagram of a network device 9000 provided in an embodiment of the present application, for example, a structural diagram of a base station. The base station 9000 can be applied to the system shown in Figure 1 to perform the functions of the network device in the above method embodiment. As shown in Figure 9, the base station 9000 may include one or more radio frequency units, such as a remote radio unit (RRU) 9002 and one or more baseband units (BBU) (also referred to as distributed units (DU)) 9001. The RRU 9002 may be referred to as a transceiver unit, corresponding to the transceiver unit 72 in Figure 7. Optionally, the transceiver unit 9002 may also be referred to as a transceiver, a transceiver circuit, or a transceiver, etc., and may include at least one antenna 9003 and a radio frequency unit 9004. Optionally, the transceiver unit 9002 may include a receiving unit and a transmitting unit, the receiving unit may correspond to a receiver (or a receiver, a receiving circuit), and the transmitting unit may correspond to a transmitter (or a transmitter, a transmitting circuit). The RRU 9002 is primarily responsible for receiving and transmitting RF signals and converting RF signals into baseband signals, for example, for sending first indication information to a terminal device. The BBU 9001 is primarily responsible for baseband processing and base station control. The RRU 9002 and BBU 9001 can be physically located together or separately, forming a distributed base station.

[0431] BBU 9001 is the control center of the base station, also known as a processing unit, which may correspond to processing unit 71 in Figure 7 and is primarily responsible for performing baseband processing functions such as channel coding, multiplexing, modulation, and spread spectrum. For example, the BBU (processing unit) may be used to control the base station to execute the network device operation procedures in the above-mentioned method embodiments, such as generating the above-mentioned indication information.

[0432] In one example, the BBU 9001 can be composed of one or more single boards, and the multiple single boards can jointly support a wireless access network with a single access standard (such as an LTE network), or can separately support wireless access networks with different access standards (such as an LTE network, a 5G network, or other networks). The BBU 9001 also includes a memory 9005 and a processor 9006. The memory 9005 is used to store necessary instructions and data. The processor 9006 is used to control the base station to perform necessary actions, such as controlling the base station to execute the operation process of the network device in the above method embodiment. The memory 9005 and the processor 9006 can serve one or more single boards. That is, a memory and a processor can be set separately on each single board. Alternatively, multiple single boards can share the same memory and processor. In addition, necessary circuits can also be set on each single board.

[0433] It should be understood that base station 9000 shown in FIG9 is capable of implementing the various processes involving the target network device in the method embodiment shown in FIG2 . The operations and / or functions of the various modules in base station 9000 are respectively for implementing the corresponding processes in the above method embodiment. For details, please refer to the description of the above method embodiment; to avoid repetition, detailed descriptions are omitted here.

[0434] The BBU 9001 can be used to perform the actions implemented within the network device described in the previous method embodiments, while the RRU 9002 can be used to perform the actions described in the previous method embodiments in which the network device sends or receives data to or from the terminal device. For details, please refer to the description in the previous method embodiments and will not be repeated here.

[0435] It should be understood that the base station 9000 shown in Figure 9 is only one possible architecture of a network device and should not constitute any limitation to this application. The method provided in this application is applicable to network devices with other architectures. For example, network devices including CUs, DUs, and active antenna units (AAUs). This application does not limit the specific architecture of the network device.

[0436] An embodiment of the present application further provides a processing device, including a processor and an interface; the processor is used to execute the method in any of the above method embodiments.

[0437] It should be understood that the processing device may be one or more chips. For example, the processing device may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0438] During implementation, each step of the above method can be completed by an integrated logic circuit of the hardware in the processor or by instructions in the form of software. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it will not be described in detail here.

[0439] It should be noted that the processor in the embodiments of the present application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment can be completed by an integrated logic circuit of the hardware in the processor or by instructions in the form of software. The above processor can be a 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, a discrete gate or transistor logic device, or a discrete hardware component. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0440] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0441] According to the method provided in the embodiments of the present application, the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the computer executes the method of any one of the embodiments shown in Figures 2 to 6.

[0442] According to the method provided in the embodiments of the present application, the present application also provides a chip system, including at least one processor and a communication interface, the communication interface and the at least one processor are interconnected by lines, and the at least one processor is used to run a computer program or instruction so that the computer executes the method of any one of the embodiments shown in Figures 2 to 6.

[0443] According to the method provided in the embodiments of the present application, the present application also provides a computer program product, including a computer program, which, when run, enables the computer to execute the method of any one of the embodiments shown in Figures 2 to 6.

[0444] The network devices in the above-mentioned various apparatus embodiments completely correspond to the network devices or terminal devices in the terminal devices and method embodiments, and the corresponding steps are performed by the corresponding modules or units. For example, the communication unit (transceiver) performs the receiving or sending steps in the method embodiments, and other steps except sending and receiving can be performed by the processing unit (processor). The functions of the specific units can be referred to the corresponding method embodiments. Among them, there can be one or more processors.

[0445] As used in this specification, the terms "component," "module," "system," and the like are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. By way of illustration, both an application running on a computing device and a computing device can be a component. One or more components can reside in a process and / or an execution thread, and a component can be located on a computer and / or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component on a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0446] Those skilled in the art will appreciate that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented using electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0447] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0448] 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 units is only 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.

[0449] Units described as separate components may or may not be physically separate, and 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.

[0450] 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.

[0451] In the above embodiments, the functions of each functional unit 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 (programs). When the computer program instructions (program) are loaded and executed on a computer, the process or function according to 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 accessed by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. Available media may be magnetic media (eg, floppy disks, hard disks, tapes), optical media (eg, high-density digital video discs (DVDs)), or semiconductor media (eg, solid state disks (SSDs)).

[0452] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, and other media that can store program codes.

[0453] The above are only specific embodiments of the present application, but the scope of protection of this 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 timing advance management method, characterized in that: include: receiving first indication information sent by a first network device, where the first indication information is used to instruct a device for managing the validity of a timing advance TA of a candidate cell; The device for managing the validity of the timing advance TA of the candidate cell is a terminal device, a first network device, or a second network device; the candidate cell is one or more; If the device that performs validity management on the TA of the candidate cell is a terminal device, the validity management of the TA of the candidate cell is performed according to the first indication information.

2. The method according to claim 1, characterized in that Also includes: receiving second indication information sent by the first network device, where the second indication information is used to indicate whether the contention-free random access CFRA process includes a random access response RAR; Sending a CFRA request to the second network device, where the CFRA request is used to instruct the second network device to obtain a TA corresponding to the candidate cell; if the second indication information indicates that the CFRA process includes a RAR, receiving the RAR sent by the second network device, where the RAR includes the TA corresponding to the candidate cell; or; A CFRA request including an RAR is sent to a second network device, where the CFRA request including the RAR is used to indicate that the CFRA process includes the RAR; and a RAR sent by the second network device is received, where the RAR includes a TA corresponding to the candidate cell.

3. The method according to claim 2, characterized in that The first indication information and the second indication information are carried in a physical downlink control channel scheduling PDCCH instruction; Alternatively, the first indication information and the second indication information are carried in a radio resource control (RRC) reconfiguration signaling message; Alternatively, the first indication information is carried in a PDCCH instruction and the second indication information is carried in an RRC reconfiguration signaling message; Alternatively, the first indication information is carried in an RRC reconfiguration signaling message and the second indication information is carried in a PDCCH instruction.

4. The method according to claim 1, wherein Also includes: receiving first configuration information and second configuration information sent by the first network device; The first configuration information includes: Information about the public validity period of the TA of the candidate cell and the TA expiration after the public validity period; Or, information on the private validity period of the TA corresponding to the candidate cell and the TA expiration corresponding to the private validity period; The second configuration information is a TA public update duration threshold of the candidate cell or a TA private update duration threshold of the corresponding candidate cell; The TA public update duration threshold of the candidate cell is a value less than the public effective duration or a value of the remaining public effective duration; the remaining public effective duration is the difference between the public effective duration and the timing time when the TA timer is started; The TA private update duration threshold of the corresponding candidate cell is a value less than the private valid duration or a value less than the remaining private valid duration, and the remaining private valid duration is the difference between the private valid duration and the timing time when the TA timer is started.

5. The method according to claim 4, characterized in that The performing validity management on the TA of the candidate cell according to the first indication information includes: The TA timer of the candidate cell is started to count. If the counted time reaches the TA public update duration threshold or the TA private update duration threshold, the update of the TA of the corresponding candidate cell is triggered.

6. The method according to claim 4, characterized in that The first configuration information and the second configuration information are carried in a downlink control channel scheduling PDCCH instruction; Alternatively, the first configuration information and the second configuration information are carried in a wireless resource control RRC reconfiguration signaling message; Alternatively, the first configuration information is carried in a PDCCH instruction and the second configuration information is carried in an RRC reconfiguration signaling message; Alternatively, the first configuration information is carried in an RRC reconfiguration signaling message and the second configuration information is carried in a PDCCH instruction.

7. The method according to claim 5, characterized in that The triggering of updating the corresponding candidate cell TA includes: Sending a CFRA request to the second network device, the CFRA request being used to instruct the second network device to obtain a current TA of the corresponding candidate cell; receiving a CFRA response sent by the second network device, the CFRA response including the current TA of the corresponding candidate cell; and updating the TA of the corresponding candidate cell according to the current TA; or; A current TA measurement process of the candidate cell is performed, and the current TA of the candidate cell is obtained; and the TA of the corresponding candidate cell is updated according to the current TA.

8. The method according to any one of claims 1 to 7, characterized in that Also includes: receiving a MAC CE signaling sent by the first network device; If there is a valid target cell TA, or if there is no valid target cell TA and the MAC CE signaling includes the target cell TA value, sending a handover indication to the second network device corresponding to the target cell, where the handover indication is used to indicate handover to the target cell; If there is no valid target cell TA and the MAC CE signaling does not include the target cell TA value, an uplink synchronization process is performed with the target cell.

9. The method according to claim 2, characterized in that Also includes: If the device that manages the validity of the TA of the candidate cell is a first network device, sending third indication information to the first network device, where the third indication information is used to indicate that the TA or TA value of the corresponding candidate cell has been obtained; If the device that manages the validity of the TA of the candidate cell is a second network device, third indication information is sent to the second network device.

10. A timing advance management method, characterized in that: include: Sending first indication information to a terminal device, where the first indication information is used to indicate a device that manages the validity of a timing advance TA of a candidate cell; the device that manages the validity of a timing advance TA of a candidate cell is a terminal device, a first network device, or a second network device; and there are one or more candidate cells; If the device that manages the validity of the TA of the candidate cell is the first network device, receiving third indication information sent by the terminal device, where the third indication information is used to indicate that the TA or TA value of the corresponding candidate cell has been obtained; The validity of the TA of the candidate cell is managed according to the third indication information.

11. The method according to claim 10, characterized in that Also includes: Second indication information is sent to the terminal device, where the second indication information is used to indicate whether the contention-free random access CFRA process includes a random access response RAR.

12. The method according to claim 11, characterized in that The first indication information and the second indication information are carried in a physical downlink control channel scheduling PDCCH instruction; Alternatively, the first indication information and the second indication information are carried in a radio resource control (RRC) reconfiguration signaling message; Alternatively, the first indication information is carried in a PDCCH instruction and the second indication information is carried in an RRC reconfiguration signaling message; Alternatively, the first indication information is carried in an RRC reconfiguration signaling message and the second indication information is carried in a PDCCH instruction.

13. The method according to claim 10, characterized in that Also includes: receiving first configuration information and second configuration information sent by the second network device; The first configuration information includes: Information about the public validity period of the TA of the candidate cell and the TA expiration after the public validity period; Or, information on the private validity period of the TA corresponding to the candidate cell and the TA expiration corresponding to the private validity period; The second configuration information is a TA public update duration threshold of the candidate cell or a TA private update duration threshold of the corresponding candidate cell; The TA public update duration threshold of the candidate cell is a value less than the public effective duration or a value less than the remaining public effective duration; the remaining public effective duration is the difference between the public effective duration and the timing time when the TA timer is started; The TA private update duration threshold of the corresponding candidate cell is a value less than the private valid duration or a value less than the remaining private valid duration, and the remaining private valid duration is the difference between the private valid duration and the timing time when the TA timer is started.

14. The method according to claim 10, characterized in that The performing validity management on the TA of the candidate cell according to the third indication information includes: The TA timer of the candidate cell is started to count. If the counted time reaches the TA public update duration threshold or the TA private update duration threshold, the update of the TA of the corresponding candidate cell is triggered.

15. The method according to claim 13, characterized in that The first configuration information and the second configuration information are carried in an independent signaling; Alternatively, the first configuration information is carried in an independent signaling and the second configuration information is carried in another independent signaling.

16. The method according to claim 14, characterized in that The triggering of updating the corresponding candidate cell TA includes: Sending a PDCCH instruction to the terminal device, the PDCCH instruction including random access resource indication information; the random access resource indication information is used to instruct the terminal device to obtain the current TA of the corresponding candidate cell from the second network device through a CFRA request; receiving fourth indication information sent by the terminal device, the fourth indication information being used to indicate that the TA of the corresponding candidate cell or the updated TA value has been updated; or; Send a measurement instruction to the terminal device, where the measurement instruction is used to instruct the terminal device to perform the current TA measurement process of the candidate cell; receive fourth indication information sent by the terminal device, where the fourth indication information is used to indicate that the TA of the corresponding candidate cell or the updated TA value has been updated.

17. The method according to any one of claims 10 to 16, characterized in that: Also includes: If there is a valid target cell TA, the target cell TA value is carried in the MAC CE signaling; Sending MAC CE signaling to the terminal device; the MAC CE signaling is used to instruct the terminal device to send a handover instruction to the second network device corresponding to the target cell; If there is no valid target cell TA, the target cell TA value is not carried in the MAC CE signaling; Sending MAC CE signaling to the terminal device; the MAC CE signaling is used to instruct the terminal device to perform an uplink synchronization process with the second network device corresponding to the target cell.

18. A timing advance management method, characterized in that: include: If the device that manages the validity of the TA of the candidate cell is a second network device, receiving third indication information sent by the terminal device, where the third indication information is used to indicate that the TA or TA value of the corresponding candidate cell has been obtained; The validity management of the TA corresponding to the candidate cell is performed according to the third indication information.

19. The method according to claim 18, characterized in that Also includes: Receiving a CFRA request sent by a terminal device, where the CFRA request is used to instruct the second network device to obtain a TA of a corresponding candidate cell, where the CFRA request is sent by the terminal to the second network device after the first network device sends second indication information to the terminal, where the second indication information is used to indicate whether a contention-free random access CFRA process includes a random access response RAR; if the second indication information indicates that the CFRA process includes an RAR, sending the RAR to the terminal device, where the RAR includes the TA of the corresponding candidate cell; or; A CFRA request including an RAR is received from a terminal device, where the CFRA request including the RAR is used to indicate that the CFRA process includes the RAR; and a RAR is sent to the terminal device, where the RAR includes a TA corresponding to a candidate cell.

20. The method according to claim 19, characterized in that The second indication information is carried in a physical downlink control channel scheduling PDCCH instruction; Alternatively, the second indication information is carried in a radio resource control (RRC) reconfiguration signaling message.

21. The method according to claim 18, wherein The performing validity management on the TA of the candidate cell according to the third indication information includes: Obtaining first configuration information and second configuration information corresponding to the candidate cell; The first configuration information includes: Information on the public validity period of the TA of the candidate cell and the TA failure after exceeding the public validity period; or information on the private validity period of the TA of the corresponding candidate cell and the TA failure after exceeding the private validity period; The second configuration information is a TA public update duration threshold of the candidate cell or a TA private update duration threshold of the corresponding candidate cell; The TA public update duration threshold of the candidate cell is a value less than the public effective duration or a value less than the remaining public effective duration; the remaining public effective duration is the difference between the public effective duration and the timing time when the TA timer is started; The TA private update duration threshold of the corresponding candidate cell is a value less than the private valid duration or a value less than the remaining private valid duration, and the remaining private valid duration is the difference between the private valid duration and the timing time when the TA timer is started.

22. The method according to claim 18, wherein The performing validity management on the TA corresponding to the candidate cell according to the third indication information includes: The TA timer is started to count. If the counted time reaches the TA public update duration threshold or the TA private update duration threshold, the update of the corresponding candidate cell TA is triggered.

23. The method according to claim 22, characterized in that The triggering of updating the corresponding candidate cell TA includes: Sending a first message to a first network device, where the first message is used to instruct the first network device to send a PDCCH instruction to the terminal device; receiving a CFRA request sent by the terminal device, where the CFRA request is used to instruct the second network device to obtain the current TA of the corresponding candidate cell; sending a CFRA response to the terminal device, where the CFRA response includes the current TA of the corresponding candidate cell; and receiving fourth indication information sent by the terminal device, where the fourth indication information is used to indicate that the TA of the corresponding candidate cell or the updated TA value has been updated. or; Send a second message to the first network device, where the second message is used to instruct the first network device to send a measurement instruction to the terminal device; receive fourth indication information sent by the terminal device, where the fourth indication information is used to indicate that the TA of the corresponding candidate cell or the updated TA value has been updated.

24. The method according to any one of claims 18 to 23, characterized in that The method further comprises: receiving a third message sent by the first network device; wherein the third message is used to indicate whether the target cell TA managed by the second network device is valid; A fourth message is sent to the first network device, where the fourth message includes information on whether the target cell TA is valid; the information on whether the target cell TA is valid is used to indicate whether the MAC CE signaling sent by the first network device to the terminal device includes the target cell TA value.

25. A terminal device, characterized in that: include: processors, memory, and transceivers; The memory stores computer-executable instructions; the transceiver is used to transmit and receive data; The processor executes the computer-executable instructions stored in the memory, so that the terminal device performs the method according to any one of claims 1 to 9.

26. A first network device, characterized in that: include: processors, memory, and transceivers; The memory stores computer-executable instructions; the transceiver is used to transmit and receive data; The processor executes the computer-executable instructions stored in the memory, so that the first network device performs the method according to any one of claims 10 to 17.

27. A second network device, characterized in that: include: processors, memory, and transceivers; The memory stores computer-executable instructions; the transceiver is used to transmit and receive data; The processor executes the computer-executable instructions stored in the memory, so that the second network device performs the method according to any one of claims 18 to 24.

28. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 24 is implemented.

29. A chip system, characterized in that: The system comprises at least one processor and a communication interface, wherein the communication interface and the at least one processor are interconnected via a line, and the at least one processor is configured to run a computer program or instruction to execute the method according to any one of claims 1 to 24.

30. A computer program product, characterized in that The method comprises a computer program which, when being executed, causes a computer to execute the method according to any one of claims 1 to 24.

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