Information determination method, terminal device and network device

Abstract

The present application relates to an information determination method, a terminal device, a first network device, a second network device, a chip, a computer-readable storage medium, a computer program product, a computer program and a communication system. The method comprises: when a first condition is met, a terminal device determining a timing advance of a first cell by means of measurement, wherein the first condition comprises initiating a first process, and the first process is used for accessing or camping on the first cell. The embodiments of the present application can reduce signaling overheads and shorten the access delay.

Description

Information determination methods, terminal devices, and network devices Technical Field

[0001] This application relates to the field of communications, and more specifically, to an information determination method, a terminal device, a first network device, a second network device, a chip, a computer-readable storage medium, a computer program product, a computer program, and a communication system. Background Technology

[0002] In wireless communication networks, Timing Advance (TA) is a crucial parameter used to ensure efficient and accurate synchronization of communication signals between User Equipment (UE) and network equipment. When a UE needs to access a target cell, such as during initial access / handover, the UE obtains the TA value for communication with the target cell by initiating a random access procedure. Obtaining TA through random access requires multiple uplink / downlink interactions between the UE and the network, resulting in high signaling overhead and increased access latency.

[0003] Summary of the Invention

[0004] This application provides an information determination method that can reduce the signaling overhead and access latency of obtaining TA.

[0005] This application provides an information determination method, including:

[0006] If the first condition is met, the terminal device determines the TA of the first cell by measurement; wherein the first condition includes initiating a first procedure, the first procedure being used to access or camp on the first cell.

[0007] This application provides an information determination method, including:

[0008] The first network device sends a first message to the terminal device; wherein the first network device is the network device of the first cell, and the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0009] This application provides an information determination method, including:

[0010] The second network device sends a first message to the terminal device; wherein the second network device is the network device of the second cell, and the second cell is the source cell or the previous cell of the terminal device; the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0011] This application provides a terminal device, including:

[0012] The first processing module is used to determine the TA of the first cell by measurement when a first condition is met; wherein the first condition includes initiating a first process, the first process being used to access or camp on the first cell.

[0013] This application provides a first network device, including:

[0014] The second communication module is used to send a first message to the terminal device; wherein the first network device is the network device of the first cell, and the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0015] This application provides a second network device, including:

[0016] The third communication module is used to send a first message to the terminal device; wherein, the second network device is the network device of the second cell, and the second cell is the source cell or the previous cell of the terminal device; the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0017] This application provides a terminal device, including a transceiver, a processor, and a memory. The memory stores a computer program, the transceiver communicates with other devices, and the processor invokes the computer program stored in the memory to cause the terminal device to execute the aforementioned information determination method.

[0018] This application provides a first network device, including a transceiver, a processor, and a memory. The memory stores a computer program, the transceiver communicates with other devices, and the processor invokes the computer program stored in the memory to cause the first network device to execute the aforementioned information determination method.

[0019] This application provides a second network device, including a transceiver, a processor, and a memory. The memory stores a computer program, the transceiver communicates with other devices, and the processor invokes the computer program stored in the memory to cause the second network device to execute the aforementioned information determination method.

[0020] This application provides a chip for implementing the above-described information determination method.

[0021] Specifically, the chip includes a processor for calling a computer program from memory, causing a device equipped with the chip to execute the aforementioned information determination method.

[0022] This application provides a computer-readable storage medium for storing a computer program, which, when run by a device, causes the device to perform the aforementioned information determination method.

[0023] This application provides a computer program product, including computer program instructions that cause a computer to execute the information determination method described above.

[0024] This application provides a computer program that, when run on a computer, causes the computer to perform the aforementioned information determination method.

[0025] In this embodiment of the application, when a terminal device initiates access or camps on a first cell, it can determine the TA of the first cell by measurement, thereby eliminating the need for multiple interactions with network devices, reducing signaling overhead and access latency. Attached Figure Description

[0026] Figure 1 is a schematic diagram of an application scenario according to an embodiment of this application.

[0027] Figure 2 is a schematic flowchart of an information determination method according to an embodiment of this application.

[0028] Figure 3 is a schematic flowchart of an information determination method according to another embodiment of this application.

[0029] Figure 4 is a schematic flowchart of an information determination method according to another embodiment of this application.

[0030] Figure 5 is a schematic block diagram of a terminal device according to an embodiment of this application.

[0031] Figure 6 is a schematic block diagram of a terminal device according to another embodiment of this application.

[0032] Figure 7 is a schematic block diagram of a first network device according to an embodiment of this application.

[0033] Figure 8 is a schematic block diagram of a second network device according to an embodiment of the present application.

[0034] Figure 9 is a schematic block diagram of a communication device according to an embodiment of this application.

[0035] Figure 10 is a schematic block diagram of a chip according to an embodiment of this application.

[0036] Figure 11 is a schematic block diagram of a communication system according to an embodiment of this application. Detailed Implementation

[0037] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0038] The technical solutions of this application embodiment can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, Advanced Long Term Evolution (LTE-A) systems, New Radio (NR) systems, evolution systems of NR systems, LTE-based access to unlicensed spectrum (LTE-U) systems, NR-based access to unlicensed spectrum (NR-U) systems, Non-Terrestrial Networks (NTN) systems, Universal Mobile Telecommunication System (UMTS), Wireless Local Area Networks (WLAN), Wireless Fidelity (WiFi), 5th Generation (5G) systems, 6th Generation (6G) systems, or other communication systems.

[0039] Traditional communication systems typically support a limited number of connections and are easy to implement. However, with the development of communication technology, mobile communication systems will not only support traditional communication but also, for example, device-to-device (D2D) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), vehicle-to-vehicle (V2V) communication, or vehicle-to-everything (V2X) communication. The embodiments of this application can also be applied to these communication systems.

[0040] In one implementation, the communication system in this application embodiment can be applied to a carrier aggregation (CA) scenario, a dual connectivity (DC) scenario, or a standalone (SA) network deployment scenario.

[0041] In one embodiment, the communication system in this application can be applied to unlicensed spectrum, wherein the unlicensed spectrum can also be considered as shared spectrum; or, the communication system in this application can also be applied to licensed spectrum, wherein the licensed spectrum can also be considered as non-shared spectrum.

[0042] This application describes various embodiments in conjunction with network devices and terminal devices. 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, etc.

[0043] Terminal devices can be stations (STAION, STA) in WLANs, cellular phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistant (PDA) devices, handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, wearable devices, terminal devices in next-generation communication systems such as NR networks, or terminal devices in future evolved Public Land Mobile Network (PLMN) networks, etc.

[0044] In the embodiments of this application, the terminal device can be deployed on land, including indoor or outdoor, handheld, wearable or vehicle-mounted; it can also be deployed on water (such as ships); and it can also be deployed in the air (such as airplanes, balloons and satellites).

[0045] In the embodiments of this application, the terminal device may be a mobile phone, a tablet computer, a computer with wireless transceiver capabilities, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical care, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, or a wireless terminal device in a smart home, etc.

[0046] By way of example and not limitation, in this embodiment, the terminal device can also be a wearable device. Wearable devices, also known as wearable smart devices, are a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, 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 merely hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are feature-rich, large in size, and can achieve complete or partial functions without relying on a smartphone, such as smartwatches or smart glasses, as well as those that focus on a specific type of application function and require the use of other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0047] In the embodiments of this application, the network device can be a device for communicating with mobile devices, such as an access point (AP) in a WLAN, an evolved Node B (eNB or eNodeB) in LTE, a relay station or access point, or a vehicle-mounted device, a wearable device, a network device (gNB) in an NR network, or a network device in a future evolved PLMN network or an NTN network, etc.

[0048] By way of example and not limitation, in this embodiment, the network device may have mobility characteristics; for example, the network device may be a mobile device. Optionally, the network device may be a satellite or a balloon station. For example, the satellite may be a low Earth orbit (LEO) satellite, a medium Earth orbit (MEO) satellite, a geostationary earth orbit (GEO) satellite, a high elliptical orbit (HEO) satellite, etc. Optionally, the network device may also be a base station located on land, water, or other similar locations.

[0049] In this embodiment, the network device can provide services to a cell. The terminal device communicates with the network device through the transmission resources (e.g., frequency domain resources, or spectrum resources) used by the cell. The cell can be the cell corresponding to the network device (e.g., a base station). The cell can belong to a macro base station or to a base station corresponding to a small cell. The small cell can include: metro cell, micro cell, pico cell, femto cell, etc. These small cells have the characteristics of small coverage area and low transmission power, and are suitable for providing high-speed data transmission services.

[0050] Figure 1 illustrates an exemplary communication system 100. The communication system includes a network device 110 and two terminal devices 120. In one embodiment, the communication system 100 may include multiple network devices 110, and the coverage area of ​​each network device 110 may include other numbers of terminal devices 120; this embodiment does not limit the scope of the present application.

[0051] In one embodiment, the communication system 100 may also include other network entities such as a Mobility Management Entity (MME) and an Access and Mobility Management Function (AMF), which are not limited in this application.

[0052] It should be understood that devices with communication functions in the network / system of this application embodiment can be referred to as communication devices. Taking the communication system shown in Figure 1 as an example, the communication device may include network devices and terminal devices with communication functions. The network devices and terminal devices can be specific devices in this application embodiment, which will not be described in detail here. The communication device may also include other devices in the communication system, such as network controllers, mobility management entities, and other network entities. This application embodiment does not limit this.

[0053] It should be understood that the terms "system" and "network" are often used interchangeably in this document. The term "and / or" in this document merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Furthermore, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0054] It should be understood that the term "instruction" mentioned in the embodiments of this application can be a direct instruction, an indirect instruction, or an indication of a relationship. For example, A instructing B can mean that A directly instructs B, such as B being able to obtain information through A; it can also mean that A indirectly instructs B, such as A instructing C, so B can obtain information through C; or it can mean that there is a relationship between A and B.

[0055] In the description of the embodiments of this application, the term "correspondence" may indicate that there is a direct or indirect correspondence between two things, or that there is an association between two things, or that there is a relationship of instruction and being instructed, configuration and being configured, etc.

[0056] To facilitate understanding of the technical solutions of the embodiments of this application, the relevant technologies of the embodiments of this application are described below. The following relevant technologies are optional solutions and can be combined with the technical solutions of the embodiments of this application in any way, and they all fall within the protection scope of the embodiments of this application.

[0057] When a UE needs to access a target cell, such as during initial access / handover, the UE obtains the TA value for communication with the target cell by initiating random access. The specific process includes:

[0058] The UE sends a random access preamble to the network equipment (e.g., base station, eNodeB or gNodeB) of the target cell, wherein the preamble is sent through the random access channel (RACH).

[0059] The network device estimates the timing advance (TA) value that the UE needs to use by receiving the preamble, and feeds back the TA value to the UE through a Random Access Response (RAR) message.

[0060] To further improve uplink access efficiency, a UE-based TA measurement scheme can be introduced into the Layer 1 / L2 Triggered Mobility (LTM) process. Specifically, the UE can determine the propagation delay difference by receiving reference signals from the current serving cell and candidate cells, thereby calculating the TA value of the candidate cell. When the UE initiates LTM towards the target cell, i.e., when the network indicates a candidate cell as the target cell for the LTM process through the LTM Cell Switching Media Access Control Unit (LTM Cell Switch MAC CE), the UE can skip the random access procedure and directly initiate uplink data transmission to the target cell based on the calculated TA, thereby reducing the handover interruption latency caused by the random access procedure.

[0061] The LTM process requires the serving cell and candidate cells to be in downlink synchronization before the TA value of the candidate cell can be obtained through UE-based TA measurement. This means the two cells are transmitting downlink reference signals synchronously at the same time. To help the UE determine which candidate cells the serving cell is downlink synchronized with, i.e., which candidate cells the UE can obtain the TA value for through UE-based TA measurement, the network needs to include the candidate cell's packet information when providing LTM candidate cell configuration to the UE. Candidate cells belonging to the same packet are considered downlink synchronized and can undergo UE-based TA measurement.

[0062] Figure 2 is a schematic flowchart of an information determination method performed by a terminal device according to an embodiment of this application. This method can optionally be applied to the system shown in Figure 1, but is not limited thereto. The method includes at least a portion of the following:

[0063] S210. Under the condition that the first condition is met, the terminal device determines the TA of the first cell by measurement; wherein the first condition includes initiating a first procedure, the first procedure being used to access or camp on the first cell.

[0064] In one embodiment, the terminal device determines the TA of a first cell by measurement, which may include: the terminal device determining the first cell by measuring a reference signal of the first cell. Optionally, the terminal device can determine the propagation delay difference between the second cell and the first cell by measuring a reference signal of the second cell and a reference signal of the first cell, and determine the TA of the first cell based on the propagation delay difference and the TA of the second cell; wherein the second cell can be any cell with a known TA. Optionally, if the downlink timing of the second cell and the first cell is synchronized, the terminal device can determine the TA of the first cell based on the TA of the second cell and the propagation delay difference; if the downlink timing of the second cell and the first cell is not synchronized, the terminal device can determine the TA of the first cell based on the TA of the second cell, the downlink timing difference (DL timing difference) between the second cell and the first cell, and the propagation delay difference.

[0065] For example, the second cell mentioned above may be the serving cell of the terminal device or the cell where the terminal device is camped. Since the step of determining the TA of the first cell based on the measurement of the reference signal and the TA of the second cell is performed when the terminal device initiates the first process, which is used to access or camp on the first cell, the second cell may be the source cell of the terminal device or the cell where it was previously camped, and the first cell can be understood as the target cell of the first process.

[0066] Obtaining the TA (Target Acquisition) based on random access (Contention-Based Random Access (CBRA) / Contention-Free Random Access (CFRA)) requires multiple uplink / downlink interactions between the terminal device and the network, including sending a preamble, receiving a RAR (Range Access Receiver), sending a Msg3 containing the terminal device's identity, and receiving a contention resolution flag. This process not only increases signaling overhead but also significantly prolongs access latency, thus impacting user experience and network performance. In contrast, the method described in this application allows the terminal device to determine the TA of the first cell through measurement when it needs to access or camp on the first cell, eliminating the need for multiple interactions with the network device. This reduces signaling overhead and access latency, improving user experience and network performance.

[0067] In this embodiment of the application, the terminal device determines the TA of the first cell by measurement. It can also be described as obtaining the TA of the first cell by the terminal device measurement method, or obtaining the TA of the first cell by the UE-based TA measurement method.

[0068] In some embodiments, the first process includes one or more of the following:

[0069] (1) Cell handover;

[0070] (2) Radio Resource Control (RRC) establishment;

[0071] (3) RRC recovery;

[0072] (4) RRC reconstruction;

[0073] (5) Reselection of the community.

[0074] In one implementation, the first process may include one of (1)-(5) above, i.e., the first condition includes the terminal device initiating a cell handover to the first cell, or establishing an RRC, or restoring an RRC, or rebuilding an RRC, or the terminal device camping on the first cell through cell reselection. When the terminal device initiates a cell handover to the first cell, or establishes an RRC, or restores an RRC, or rebuilds an RRC, or camps on the first cell through cell reselection, the TA of the first cell can be determined by measurement.

[0075] In one implementation, the first process may include multiple items from (1)-(5) above. When the first process includes multiple items, a first condition can be determined to be met when any one of the first processes is initiated. For example, if the first process includes cell handover and cell reselection, the terminal device can determine the TA of the first cell by measurement when initiating cell handover to the first cell and when camping on the first cell through cell reselection. Optionally, the first process may include any multiple items from (1)-(5) above, and this application does not limit this.

[0076] Optionally, cell handover may include LTM handover.

[0077] According to the above embodiments, terminal devices can effectively utilize UE-based TA measurement technology in a wide range of scenarios, thereby reducing signaling overhead and access latency, and improving user experience and network performance in one or more scenarios.

[0078] In some embodiments, the first condition further includes one or more of the following:

[0079] The second cell is valid; where the second cell is the source cell or the previous cell where the user resides.

[0080] The first cell supports obtaining the TA (Transmission Aspect) of the first cell through measurement by terminal equipment.

[0081] For example, the first condition further includes the TA of the second cell being valid. If the terminal device initiates the first process and the TA of the second cell is valid, it determines the TA of the first cell through measurement. For instance, it measures the reference signals of the first and second cells to obtain the propagation delay difference, and determines the TA of the first cell based on the valid TA of the second cell and the propagation delay difference. By setting the TA of the first cell to be determined through measurement when the TA of the second cell is valid, the effectiveness of obtaining the TA using the UE-based TA measurement method can be improved.

[0082] For example, the first condition further includes that the first cell supports obtaining the TA of the first cell through measurement by the terminal device. In practical applications, one or more cells (neighboring cells / candidate cells, etc.) may support obtaining the TA of the first cell through measurement by the terminal device, and one or more cells (neighboring cells / candidate cells, etc.) may not support obtaining the TA of the first cell through measurement by the terminal device. When the terminal device initiates the first process and the first cell supports obtaining the TA of the first cell through measurement by the terminal device, the terminal device determines the TA of the first cell through measurement.

[0083] For example, the first condition also includes that the TA of the second cell is valid and the first cell supports obtaining the TA of the first cell through measurement by the terminal device. Then, when the terminal device initiates the first process and the TA of the second cell is valid and the first cell supports obtaining the TA of the first cell through measurement by the terminal device, the terminal device determines the TA of the first cell by measurement.

[0084] The terminal device can determine whether the above conditions are met through one or more methods. Specifically, regarding whether the TA of the second cell is valid, the terminal device can determine it based on the measurement results of the second cell and / or the Timing Advance Timer (TAT).

[0085] In some embodiments, the information determination method may include: if the change in the measurement result of the terminal device in the second cell is less than or equal to a first threshold and / or the TAT is in operation, determining that the TA of the second cell is valid.

[0086] For example, the terminal device determines that the TA of the second cell is valid if the change in the measurement result of the second cell is less than or equal to a first threshold. Alternatively, the terminal device determines that the TA of the second cell is valid if the TAT is running. Or, the terminal device determines that the TA of the second cell is valid if the change in the measurement result of the second cell is less than or equal to the first threshold and the TAT is running. Here, the change in the measurement result can refer to the amount of change between two or more measurement results. Optionally, the change can be understood as the absolute value of the difference. In practical applications, the change can include an increase and / or a decrease.

[0087] In some embodiments, the measurement results may include one or more of the following: Reference Signal Receiving Power (RSRP), Reference Signal Receiving Quality (RSRQ), Reference Signal Strength Indicator (RSSI), and Signal to Interference plus Noise Ratio (SINR).

[0088] In some embodiments, the change in the measurement result includes the change between two adjacent measurement results and / or the change between the current measurement result and the measurement result at the time of the last TA update. The change can be an increase or a decrease. In other words, the change in the measurement result can include: the absolute value of the difference between two adjacent measurement results, and / or the absolute value of the difference between the current measurement result and the measurement result at the time of the last TA update.

[0089] For example, the change in the measurement result includes the change between the currently measured RSRP of the second cell and the previously measured RSRP of the second cell. Alternatively, the change in the measurement result includes the change between the currently measured RSRP of the second cell and the RSRP measured during the last TA update. Or, the change in the measurement result includes the change between the currently measured RSRP of the second cell and the previously measured RSRP of the second cell, and the change between the currently measured RSRP of the second cell and the RSRP measured during the last TA update. When both changes are less than a preset threshold (the two differences can correspond to the same threshold or different thresholds), the TA of the second cell is determined to be valid. Determining the validity of the TA of the second cell based on the change in the measurement result avoids using the TA information of the second cell under unstable conditions to determine the TA of the first cell, improving the accuracy of obtaining the TA of the first cell through terminal device measurement.

[0090] Optionally, the TAT used to determine whether the TA of the second cell is valid can be a global TAT or a TAT specific to the second cell. For example, the terminal device maintains a TAT for the currently recorded TA. When the terminal device's serving cell is the second cell or the terminal device is camped on the second cell, this TAT ​​is used to determine whether the TA of the second cell is valid. When the terminal device successfully switches to the first cell or camps on the first cell, it will restart the TAT, which is then used to determine whether the TA of the first cell is valid. Alternatively, the terminal device maintains different TATs for different cells; that is, it maintains a TAT corresponding to the first cell for the first cell and a TAT corresponding to the second cell for the second cell. The terminal device determines whether the TA of the second cell is valid based on the TAT corresponding to the second cell.

[0091] In some embodiments, the information determination method may include: the terminal device restarting the time-of-use (TAT) when updating the TA of the second cell. Optionally, the terminal device restarts the TAT every time it updates the TA of the second cell. Therefore, the TAT can be used to determine whether the duration of the updated TA of the second cell has exceeded the duration of the TAT, thereby determining whether the TA of the second cell is valid based on the duration, avoiding the use of lagging second cell TA information to determine the TA of the first cell, and improving the accuracy of obtaining the TA of the first cell through terminal device measurement.

[0092] In some embodiments, the information determination method may include: the terminal device periodically or based on a first event to update the TA of the second cell within the second cell. For example, when the terminal device moves within the second cell (e.g., the source cell / source serving cell), it may trigger a TA update at regular intervals to avoid TA update lag in the second cell. Alternatively, when the terminal device moves within the second cell (e.g., the source cell / source serving cell), it may update the TA of the second cell based on a first event, wherein the first event may be an event characterizing a change in the terminal device's speed / location, or a failure of service in the second cell to meet requirements.

[0093] In some embodiments, the first event includes one or more of the following:

[0094] The measurement result of the second cell is less than the second threshold;

[0095] The change in the measurement results of two consecutive measurements in the second cell is greater than the third threshold;

[0096] The change in the position of the terminal device exceeds the fourth threshold.

[0097] The terminal device's moving speed exceeds the fifth threshold.

[0098] For example, the first event may include any of the above events. When any of these events occurs, the terminal device updates the TA (Telematics Acquisition) of the second cell (serving cell or camped cell) and restarts the TAT (Telematics Acquisition). Then, when initiating the first procedure to the first cell, it determines whether the TA of the second cell is valid based on the TAT. If the TA of the second cell is valid, it determines the TA of the first cell through measurement based on the TA of the second cell. The first event may also include any combination of the above events (e.g., the measurement result of the second cell is less than a second threshold and the terminal device's moving speed is greater than a fifth threshold). When multiple events occur (e.g., the measurement result of the second cell is less than the second threshold and the terminal device's moving speed is greater than the fifth threshold), the terminal device updates the TA of the second cell and restarts the TAT. In practical applications, the first event can be determined according to system requirements, protocol agreements, system conventions, network configurations, etc., and this application does not impose any restrictions on this.

[0099] Regarding whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device, the terminal device can determine this based on the message sent by the network.

[0100] In some embodiments, the information determination method may include: the terminal device determining whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device based on a first message sent by the first cell or the second cell.

[0101] In some embodiments, the first message includes an RRC message sent by the second cell. For example, when the terminal device is in the second cell (i.e., the second cell is the serving cell), the terminal device receives the RRC message sent by the second cell and determines, based on the RRC message, whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device. Optionally, the RRC message is a terminal device-specific RRC signaling.

[0102] In some embodiments, the RRC message is used to instruct the terminal device to switch to the first cell. For example, the RRC message can be a message sent by the network device of the second cell during the first process. For instance, the RRC message could be an RRC reconfiguration message, an RRC connection release message, etc.

[0103] In some embodiments, the first message includes a broadcast message sent by the first cell or the second cell. For example, when the terminal device is in an idle state, the terminal device receives a first message (e.g., a broadcast system message) sent by the first cell or the second cell, and determines whether the first cell supports obtaining the TA of the first cell by means of measurement by the terminal device based on the first message.

[0104] In some embodiments, the first message is used to indicate one or more of the following: whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device; whether the first cell and the second cell are downlink timing synchronized; and the downlink timing difference between the first cell and the second cell.

[0105] For example, the first message can directly indicate whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device. For instance, the first message includes relevant information about the first cell, which includes an indication indicating whether the TA of the first cell is supported through measurement by the terminal device (e.g., indicated by 0 or 1). Alternatively, the first message can implicitly indicate whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device. For instance, by indicating whether the downlink timing of the first cell and the second cell is synchronized and / or the downlink timing difference between the first cell and the second cell, the terminal device can determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0106] In some embodiments, the first message is used to determine whether the downlink timing of the second cell and the first cell is synchronized, and / or to obtain the downlink timing difference between the second cell and the first cell. Accordingly, the terminal device determines whether the first cell supports obtaining the TA of the first cell by measurement based on the first message sent by the first cell or the second cell, including: if the terminal device determines that the downlink timing of the second cell and the first cell is synchronized based on the first message, or obtains the downlink timing difference between the second cell and the first cell based on the first message, it determines that the first cell supports obtaining the TA of the first cell by measurement.

[0107] For example, the first message indicates whether the downlink timing of the second cell and the first cell is synchronized. If the downlink timing of the second cell and the first cell is synchronized based on the first message, the terminal device determines that the first cell supports obtaining the TA of the first cell through measurement by the terminal device; if the downlink timing of the second cell and the first cell is not synchronized based on the first message, the terminal device determines that the first cell does not support obtaining the TA of the first cell through measurement by the terminal device.

[0108] For example, the first message indicates the downlink timing difference between multiple cells. If the downlink timing difference between the first cell and the second cell can be determined based on the first message, the terminal device determines that the first cell supports obtaining the TA of the first cell through terminal device measurement; if the downlink timing difference between the first cell and the second cell cannot be determined based on the first message, the terminal device determines that the first cell does not support obtaining the TA of the first cell through terminal device measurement.

[0109] For example, the first message indicates whether downlink timing is synchronized between multiple cells and the downlink timing difference between multiple cells. If the first message determines that the downlink timing of the second cell is synchronized with that of the first cell, the terminal device determines that the first cell supports obtaining the TA of the first cell through terminal device measurement. If the first message determines that the downlink timing of the second cell is not synchronized with that of the first cell, but the downlink timing difference between the first cell and the second cell can be determined based on the first message, the terminal device determines that the first cell supports obtaining the TA of the first cell through terminal device measurement. If the first message determines that the downlink timing of the second cell is not synchronized with that of the first cell, and the downlink timing difference between the first cell and the second cell cannot be determined based on the first message, the terminal device determines that the first cell does not support obtaining the TA of the first cell through terminal device measurement.

[0110] In some embodiments, the first message includes one or more of the following:

[0111] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0112] Whether the downlink timing synchronization is between the first cell and the second cell;

[0113] Downlink timing difference between the first cell and the second cell;

[0114] Grouping information for candidate cells, neighboring cells, or frequency points;

[0115] Downlink timing difference between different groups;

[0116] A list of cells, frequencies, or groups that have the same downlink timing information as the first or second cell;

[0117] A list of cells, frequencies, or groups that have different downlink timing information from the first cell or the second cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the first cell or the second cell;

[0118] First indication information for a first cell or a second cell; wherein the first indication information is used to indicate the group to which the first cell or the second cell belongs.

[0119] In one or more of the above information, the first message may directly indicate whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device, whether the first cell and the second cell are downlink timing synchronized, and one or more of the downlink timing difference between the first cell and the second cell. Alternatively, it may indicate, through grouping, whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device, whether the first cell and the second cell are downlink timing synchronized, and one or more of the downlink timing difference between the first cell and the second cell. In some embodiments, the method further includes: if the terminal device determines that the second cell and the first cell belong to the same group based on the first message, then the second cell and the first cell are downlink timing synchronized. Optionally, the terminal device may determine whether the first cell and the second cell belong to the same group based on one or more of the grouping information in the first message, the downlink timing difference between different groups, a specific cell list / frequency point list / group list, and the first indication information.

[0120] To facilitate understanding of the application of the various information items in the first message, several examples of first messages are provided below.

[0121] Example 1: The first message is an instruction for both the first and second cells. For example, the first message is an RRC message sent by the second cell, which instructs the terminal device to switch to the first cell.

[0122] Optionally, the first message may include: whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device (e.g., indicating support or non-support through 1 bit information), and / or whether the first cell and the second cell are downlink timing synchronized, and / or the downlink timing difference between the first cell and the second cell.

[0123] For example, the first message can directly indicate whether the first cell supports or does not support obtaining the TA of the first cell through measurement by the terminal device using 1 bit information (0 or 1).

[0124] For example, the first message uses 1 bit (0 or 1) to indicate whether the downlink timing of the first cell and the second cell is synchronized. If the downlink timing of the first cell and the second cell is synchronized, the terminal device can determine that the first cell supports obtaining the TA of the first cell through measurement by the terminal device. If the downlink timing of the first cell and the second cell is not synchronized, the first message indicates that the first cell does not support obtaining the TA of the first cell through measurement by the terminal device. Alternatively, the downlink timing difference between the first cell and the second cell is optional. If the first message also includes the downlink timing difference between the first cell and the second cell, it indicates that the first cell supports obtaining the TA of the first cell through measurement by the terminal device. If the first message does not include the downlink timing difference between the first cell and the second cell, it indicates that the first cell does not support obtaining the TA of the first cell through measurement by the terminal device.

[0125] Example 2: The first message indicates multiple candidate cells, multiple neighboring cells, or cells on multiple frequency points. For example, the first message is an RRC message or broadcast message sent by the serving cell (second cell), which is used to indicate information about candidate cells / neighboring cells / frequency points.

[0126] Optionally, the first message may include: grouping information of candidate cells / neighboring cells / frequency points, and / or, downlink timing difference between different groups, and / or, first indication information of the second cell. Cells / frequency points within the same group have the same downlink timing information, i.e., downlink timing synchronization of cells or frequency points (including one or more cells on a frequency point) within the same group. If the first cell belongs to a certain cell group / or the frequency point corresponding to the first cell belongs to a certain frequency point group, the terminal device can obtain the TA of the first cell through terminal device measurement.

[0127] For example, the first message may include grouping information for candidate cells / neighboring cells / frequency points. This grouping information may be a list of candidate cells, a list of neighboring cells, or a list of frequency points corresponding to each group, enabling the terminal device to determine which group each cell belongs to. The terminal device may pre-determine the group to which the second cell belongs (e.g., through other messages), or determine the group to which the second cell belongs through the aforementioned list. Alternatively, the first message may also include first indication information for the second cell. Based on this, if the first cell is one of the cells or a cell on one of the frequency points, the terminal device can determine whether that cell belongs to the same group as the second cell, thereby determining whether the first cell and the second cell are in downlink timing synchronization.

[0128] For example, the first message may include grouping information for candidate cells / neighboring cells / frequency points and downlink timing differences between different groups, enabling the terminal device to determine which group each cell belongs to and the downlink timing differences between different groups. The terminal device may predetermine the group to which the second cell belongs (e.g., through other messages), or determine the group to which the second cell belongs through the aforementioned list, or the first message may also include first indication information for the second cell. Based on this, if the first cell is one of the cells or a cell on one of the frequencies, the terminal device can determine whether that cell belongs to the same group as the second cell, and can also determine the downlink timing difference in the case of different groups. Thus, the terminal device can determine downlink timing synchronization between the first cell and the second cell or obtain the downlink timing difference.

[0129] For example, the first message may include the downlink timing difference between different groups. The terminal device can determine the group to which each cell belongs through other messages or pre-configured information, thereby determining whether the first cell and the second cell belong to the same group. In the case of different groups, the downlink timing difference between the first cell and the second cell can be obtained from the first message.

[0130] In one implementation, the aforementioned grouping information includes a list of cells or a list of frequencies associated with each group. Specifically, the aforementioned grouping information is a list of cells or frequencies under each group. For example, the first message includes: Group 1: {Cell 1, Cell 2, Cell 3}; Group 2: {Cell 4, Cell 5, Cell 6}.

[0131] In another implementation, the aforementioned grouping information includes first indication information associated with a cell or frequency point. Specifically, the first message may include first indication information associated with each candidate cell / neighboring cell / frequency point, and / or, first indication information associated with a second cell. Cells with the same first indication information value have the same downlink timing information. Here, the first indication information can be understood as a group identifier, that is, the aforementioned grouping information includes the group identifier of each cell / frequency point among multiple cells / frequency points. If two cells have the same group identifier, they can be considered to be cells in the same group, and the two cells have the same downlink timing information / downlink timing synchronization. Optionally, when the first indication information associated with a cell or frequency point is used as the grouping information, the first message may further include the downlink timing difference between cells / frequency points corresponding to different first indication information values, that is, the downlink timing difference between different groups.

[0132] Example 3: The first message is an instruction directed to the second cell. For example, the first message is a broadcast message or RRC message sent by the second cell.

[0133] Optionally, the first message may include: a list of cells, frequency points, or groups that have the same downlink timing information as the second cell. If the first cell is in the cell list, or the frequency point where the first cell is located is in the frequency point list, or the group where the first cell is located is in the group list, the terminal device can determine that the first cell and the second cell have the same downlink timing information, i.e., downlink timing is synchronized, and the terminal device can obtain the TA of the first cell by measurement. If the first cell is not in the cell list, or the frequency point where the first cell is located is not in the frequency point list, or the group where the first cell is located is not in the group list, the terminal device can determine that the downlink timing of the first cell and the second cell is not synchronized, and the terminal device cannot obtain the TA of the first cell by measurement.

[0134] Optionally, the first message may include: a list of cells, frequencies, or groups that have the same downlink timing information as the second cell, a list of cells, frequencies, or groups that have different downlink timing information as the second cell, and the downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information as the second cell. The terminal device can determine whether the downlink timing of the first cell is synchronized with that of the second cell based on the list of cells, frequencies, or groups that have the same downlink timing information as the second cell. If they are not synchronized, the terminal device can also determine whether the downlink timing difference between the first cell and the second cell can be obtained based on the list of cells, frequencies, or groups that have different downlink timing information as the second cell and the downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information as the second cell, thereby determining whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0135] Optionally, the first message may include a list of cells, frequencies, or groups that have different downlink timing information from the second cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the second cell. Thus, the terminal device can determine whether it can obtain the downlink timing difference between the first cell and the second cell based on whether the first cell is in the cell list or whether the frequency of the first cell is in the frequency list, thereby determining whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0136] Example 4: The first message is an instruction directed to the first cell. For example, the first message is a broadcast message sent by the first cell.

[0137] Optionally, the first message may include: a list of cells, frequency points, or groups that have the same downlink timing information as the first cell. If the second cell is in the cell list, or the frequency point where the second cell is located is in the frequency point list, or the group where the second cell is located is in the group list, the terminal device can determine that the first cell and the second cell have the same downlink timing information, i.e., downlink timing is synchronized, and the terminal device can obtain the TA of the first cell by measurement. If the second cell is not in the cell list, or the frequency point where the second cell is located is not in the frequency point list, or the group where the second cell is located is not in the group list, the terminal device can determine that the downlink timing of the first cell and the second cell is not synchronized, and the terminal device cannot obtain the TA of the first cell by measurement.

[0138] Optionally, the first message may include: a list of cells, frequencies, or groups with the same downlink timing information as the first cell, a list of cells, frequencies, or groups with different downlink timing information than the first cell, and the downlink timing difference corresponding to the list of cells, frequencies, or groups with different downlink timing information than the first cell. The terminal device can determine whether the downlink timing of the first cell is synchronized with that of the second cell based on the list of cells, frequencies, or groups with the same downlink timing information as the first cell. If they are not synchronized, the terminal device can also determine whether the downlink timing difference between the first cell and the second cell can be obtained based on the list of cells, frequencies, or groups with different downlink timing information as the first cell, and the downlink timing difference corresponding to the list of cells, frequencies, or groups with different downlink timing information as the first cell, thereby determining whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0139] Optionally, the first message may include a list of cells, frequencies, or groups that have different downlink timing information from the first cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the first cell. Thus, the terminal device can determine whether it can obtain the downlink timing difference between the first cell and the second cell based on whether the second cell is in the cell list or whether the frequency of the second cell is in the frequency list, thereby determining whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0140] Optionally, the first message may include: packet information of candidate cells, neighboring cells, or frequency points, and / or, packet information of the first cell, and / or, downlink timing difference between different packets. For example, the first message may include first indication information associated with candidate cells, neighboring cells, or frequency points, and / or, first indication information associated with the first cell. The terminal device can determine whether the downlink timing of the first cell and the second cell is synchronized, and / or, the downlink timing difference between the first cell and the second cell, based on the first indication information associated with each cell and the downlink timing difference between different packets.

[0141] Optionally, the above examples can be implemented independently or in combination. For example, in one implementation, the terminal device determines whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device based on any of the above examples; in another implementation, the RRC message sent by the second cell includes downlink timing relationships between multiple cells (e.g., Cell1-Cell8). When the terminal device moves between these multiple cells (e.g., Cell1-Cell8), it can determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device (i.e., TA measurement configuration based on the UE) based on the configuration provided by the RRC message. When the terminal device moves from any of the multiple cells to another cell outside the multiple cells based on cell reselection (e.g., from Cell8 to Cell9 based on cell reselection), the terminal device can determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device based on a broadcast message (e.g., a broadcast message of Cell8). Optionally, at this time, the terminal device can release the information obtained through the RRC message (release the TA measurement configuration based on the UE obtained through the RRC message).

[0142] It should be noted that the above examples are some optional implementations of the first message. In actual applications, the first message can also include other content or other information combinations. Specifically, the content of the first message can be set according to system requirements, protocol agreements, system conventions, network configurations, etc. For the sake of brevity, they will not be listed one by one here.

[0143] In some embodiments, the information determination method may further include: the terminal device restarting the TAT after successfully obtaining the TA of the first cell.

[0144] Optionally, the TAT is used to determine whether the latest recorded TA is valid. For example, the TAT is a global TAT; when the terminal device moves within the second cell, the terminal device can periodically or based on the triggering of the first event update the TA of the second cell, restarting the TAT each time it is updated, and restarting the TAT when the terminal device successfully obtains the TA of the first cell.

[0145] The process of determining whether the terminal device has successfully obtained the TA of the first cell can be implemented by the terminal device itself, or it can be implemented through communication.

[0146] In some embodiments, the information determination method may include: after determining the TA of the first cell by measurement, the terminal device sends data and / or signaling to the network device of the first cell; upon receiving feedback information from the network device, the terminal device determines that it has successfully obtained the TA of the first cell.

[0147] That is, based on the acquired TA, the terminal device sends uplink data / signaling to the first cell. If the terminal device receives downlink feedback from the first cell (this downlink feedback can be downlink data / signaling or uplink transmission scheduling), it is considered that the TA of the first cell has been successfully acquired.

[0148] In some embodiments, the terminal device transmits the aforementioned data and / or signaling based on CB-CG resources.

[0149] In some embodiments, the information determination method may further include: the terminal device stopping TAT if it fails to acquire the TA of the first cell, and / or if it fails to acquire downlink timing synchronization information or downlink timing difference between the first cell and the second cell. Optionally, if the terminal device fails to acquire the TA of the first cell, and / or if it fails to acquire downlink timing synchronization information or downlink timing difference between the first cell and the second cell, it stops TAT ​​when the terminal device initiates a first procedure to camp on or access the first cell. Based on this, the TA of the second cell is invalidated, avoiding the subsequent use of delayed TA information.

[0150] In some embodiments, the information determination method may include: upon successfully acquiring the TA of a first cell, the terminal device initiates a TAT associated with the first cell. In this embodiment, the terminal device may maintain corresponding TATs for each cell separately, including maintaining a TAT associated with the first cell and a TAT associated with the second cell. This effectively utilizes the acquired TA information of each cell, reducing redundant measurements and repeated random access TA acquisition processes, thereby reducing resource / signaling overhead and access latency.

[0151] In some embodiments, the information determination method may include: the terminal device storing the TA of the second cell and maintaining the TAT associated with the second cell in operation. Specifically, when the terminal device initiates a first process to camp on or access the first cell, the terminal device stores the TA of the second cell and maintains the TAT associated with the second cell in operation.

[0152] For example, if the terminal device is currently camped in Cell 1 (the second cell), based on RRC messages or system broadcast messages, the terminal device determines that the cells whose TA can be obtained through measurement include Cell 3, Cell 4, and Cell 5. The terminal device determines the target cell (the first cell) as Cell 2 (not necessarily a cell whose TA can be obtained through measurement) based on cell reselection criteria. Therefore, when the terminal device accesses Cell 2, it needs to initiate RACH to establish uplink synchronization with the target Cell 2. Simultaneously, the terminal device stores the TA of Cell 1 and maintains the TAT associated with that TA. When the terminal device moves back to Cell 1, if the TAT remains active, the TA of Cell 1 is considered still valid, thus eliminating the need to obtain the TA of Cell 1 through measurement or RACH.

[0153] Optionally, the TAT associated with the first / second cell can also be the TAT associated with the packet / set to which the first / second cell belongs. That is, the terminal device uses different TATs to maintain the TA of different cell sets / packets. For example, Cell1 / 3 / 4 / 5 use TAT1. When the terminal device moves between these cells, it updates the TA of these cells by measurement and restarts TAT1. Cell2 / 6 / 7 / 8 use TAT2. When the terminal device moves between these cells, it updates the TA of these cells by measurement and restarts TAT2.

[0154] Figure 3 is a schematic flowchart of an information determination method performed by a first network device according to an embodiment of this application. This method can optionally be applied to the system shown in Figure 1, but is not limited thereto. The method includes at least a portion of the following:

[0155] S310, The first network device sends a first message to the terminal device; wherein, the first network device is the network device of the first cell, and the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0156] In some embodiments, the first message is used by the terminal device to determine whether the first cell supports obtaining the TA of the first cell by means of terminal device measurement, so as to obtain the TA of the first cell by means of terminal device measurement when initiating the first process for camping on or accessing the first cell.

[0157] In some embodiments, the first message includes a broadcast message.

[0158] In some embodiments, the first message is used to indicate one or more of the following:

[0159] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0160] Whether the downlink timing synchronization is between the first cell and the second cell;

[0161] Downlink timing difference between the first cell and the second cell.

[0162] In some embodiments, the first message includes one or more of the following:

[0163] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0164] Whether the downlink timing synchronization is between the first cell and the second cell;

[0165] Downlink timing difference between the first cell and the second cell;

[0166] Grouping information for candidate cells, neighboring cells, or frequency points;

[0167] Downlink timing difference between different groups;

[0168] A list of cells, frequencies, or groups that have the same downlink timing information as the first cell;

[0169] A list of cells, frequencies, or groups that have different downlink timing information from the first cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the second cell;

[0170] First indication information for the first cell or the second cell; wherein, the first indication information is used to indicate the group to which the first cell or the second cell belongs.

[0171] In some embodiments, the group information includes a list of cells or a list of frequencies associated with the group.

[0172] In some embodiments, the packet information includes first indication information associated with a cell or frequency point, and cells with the same first indication information value have the same downlink timing information.

[0173] In some embodiments, the information determination method may include:

[0174] The first network device receives data and / or signaling sent by the terminal device;

[0175] The first network device sends feedback information to the terminal device; the feedback information is used to determine that the terminal device has successfully obtained the TA of the first cell.

[0176] Specific examples of the method executed by the first network device in this application embodiment can be found in the descriptions of the first cell sending a first message and the terminal device determining whether it has successfully obtained the TA of the first cell in the foregoing embodiments. For the sake of brevity, they will not be repeated here.

[0177] Figure 4 is a schematic flowchart of an information determination method performed by a second network device according to an embodiment of this application. This method can optionally be applied to the system shown in Figure 1, but is not limited thereto. The method includes at least a portion of the following:

[0178] S410, the second network device sends a first message to the terminal device; wherein, the second network device is the network device of the second cell, and the second cell is the source cell or the previous camped cell of the terminal device; the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0179] In some embodiments, the first message is used by the terminal device to determine whether the first cell supports obtaining the TA of the first cell by means of terminal device measurement, so as to obtain the TA of the first cell by means of terminal device measurement when initiating the first process for camping on or accessing the first cell.

[0180] In some embodiments, the first message includes an RRC message sent by the second cell.

[0181] In some embodiments, the RRC message is used to instruct the terminal device to switch to the first cell.

[0182] In some embodiments, the first message includes a broadcast message sent by the second cell.

[0183] In some embodiments, the first message is used to indicate one or more of the following:

[0184] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0185] Whether the downlink timing synchronization is between the first cell and the second cell;

[0186] Downlink timing difference between the first cell and the second cell.

[0187] In some embodiments, the first message includes one or more of the following:

[0188] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0189] Whether the downlink timing synchronization is between the first cell and the second cell;

[0190] Downlink timing difference between the first cell and the second cell;

[0191] Grouping information for candidate cells, neighboring cells, or frequency points;

[0192] Downlink timing difference between different groups;

[0193] A list of cells, frequencies, or groups that have the same downlink timing information as the second cell;

[0194] A list of cells, frequencies, or groups that have different downlink timing information from the second cell, and the downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the second cell;

[0195] First indication information for the first cell or the second cell; wherein, the first indication information is used to indicate the group to which the first cell or the second cell belongs.

[0196] In some embodiments, the group information includes a list of cells or a list of frequencies associated with the group.

[0197] In some embodiments, the packet information includes first indication information associated with a cell or frequency point, and cells with the same first indication information value have the same downlink timing information.

[0198] For specific examples of the method executed by the second network device in this application embodiment, please refer to the relevant description of the second cell sending the first message in the foregoing embodiments. For the sake of brevity, it will not be repeated here.

[0199] Obtaining the TA (Target Acquisition) based on random access (CBRA / CFRA) requires multiple uplink / downlink interactions between the terminal device and the network, including sending a preamble, receiving a RAR (Range Access Receiver), sending a Msg3 containing the UE's identity identifier, and receiving a contention resolution identifier. This process not only increases signaling overhead but also significantly prolongs access latency, thus impacting user experience and network performance. In contrast, the method described in this application allows the terminal device to determine the TA of the first cell through measurement when it needs to access or camp on the first cell. This eliminates the need for multiple interactions with the network device, reducing signaling overhead and access latency, and improving user experience and network performance.

[0200] Figure 5 is a schematic block diagram of a terminal device 500 according to an embodiment of the present application. The terminal device 500 may include:

[0201] The first processing module 510 is used to determine the TA of the first cell by measurement when a first condition is met; wherein the first condition includes initiating a first process, the first process being used to access or camp on the first cell.

[0202] In some embodiments, the first process includes one or more of the following:

[0203] Cell handover;

[0204] RRC established;

[0205] RRC recovery;

[0206] RRC reconstruction;

[0207] The neighborhood was re-selected.

[0208] In some embodiments, the first condition further includes one or more of the following:

[0209] The second cell is valid; where the second cell is the source cell or the previous cell where the user resides.

[0210] The first cell supports obtaining the TA (Transmission Aspect) of the first cell through measurement by terminal equipment.

[0211] In some embodiments, the first processing module 510 is further configured to:

[0212] If the change in the measurement result of the second cell is less than or equal to the first threshold and / or the TAT is in operation, the TA of the second cell is determined to be valid.

[0213] In some embodiments, the change in the measurement result includes the change between two consecutive measurement results and / or the change between the current measurement result and the measurement result at the time of the last TA update.

[0214] In some embodiments, the first processing module 510 is further configured to:

[0215] Restart the TAT when updating the TA of the second cell.

[0216] In some embodiments, the first processing module 510 is further configured to:

[0217] Within the second cell, the TA of the second cell is updated periodically or based on the triggering of the first event.

[0218] In some embodiments, the first event includes one or more of the following:

[0219] The measurement result of the second cell is less than the second threshold;

[0220] The change in the measurement results of two consecutive measurements in the second cell is greater than the third threshold;

[0221] The change in the position of the terminal device exceeds the fourth threshold.

[0222] The terminal device's moving speed exceeds the fifth threshold.

[0223] In some embodiments, the first processing module 510 is further configured to:

[0224] Based on the first message sent by the first cell or the second cell, determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0225] In some embodiments, the first message includes an RRC message sent by the second cell.

[0226] In some embodiments, the RRC message is used to instruct the terminal device to switch to the first cell.

[0227] In some embodiments, the first message includes a broadcast message sent by a first cell or a second cell.

[0228] In some embodiments, the first message is used to indicate one or more of the following:

[0229] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0230] Whether the downlink timing synchronization is between the first cell and the second cell;

[0231] Downlink timing difference between the first cell and the second cell.

[0232] In some embodiments, the first processing module 510 is further configured to:

[0233] If the downlink timing synchronization between the second cell and the first cell is determined based on the first message, or if the downlink timing difference between the second cell and the first cell is obtained based on the first message, it is determined that the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0234] In some embodiments, the first message includes one or more of the following:

[0235] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0236] Whether the downlink timing synchronization is between the first cell and the second cell;

[0237] Downlink timing difference between the first cell and the second cell;

[0238] Grouping information for candidate cells, neighboring cells, or frequency points;

[0239] Downlink timing difference between different groups;

[0240] A list of cells, frequencies, or groups that have the same downlink timing information as the first or second cell;

[0241] A list of cells, frequencies, or groups that have different downlink timing information from the first or second cell;

[0242] Downlink timing difference corresponding to a list of cells, frequency points, or groups that have different downlink timing information from the first or second cell;

[0243] First indication information for the first cell or the second cell; wherein, the first indication information is used to indicate the group to which the first cell or the second cell belongs.

[0244] In some embodiments, the group information includes a list of cells or a list of frequencies associated with the group.

[0245] In some embodiments, the packet information includes first indication information associated with a cell or frequency point, and cells with the same first indication information value have the same downlink timing information.

[0246] In some embodiments, the first processing module 510 is further configured to:

[0247] If the second cell and the first cell belong to the same group based on the first message, the downlink timing synchronization between the second cell and the first cell is determined.

[0248] In some embodiments, the first processing module 510 is further configured to:

[0249] If the TA of the first cell is successfully obtained, restart the TAT.

[0250] In some embodiments, the first processing module 510 is further configured to:

[0251] If the TA of the first cell is not successfully obtained, and / or if the downlink timing synchronization information or downlink timing difference between the first cell and the second cell is not obtained, the TAT shall be stopped.

[0252] In some embodiments, the first processing module 510 is further configured to:

[0253] If the TA of the first cell is successfully obtained, the TAT associated with the first cell is started.

[0254] In some embodiments, the first processing module 510 is further configured to:

[0255] Store the TA of the second cell and keep the TAT associated with the second cell running.

[0256] In some embodiments, as shown in FIG6, the terminal device 500 further includes a first communication module 610:

[0257] The first communication module 610 is used to send data and / or signaling to the network equipment of the first cell after determining the TA of the first cell through measurement;

[0258] The first processing module 510 is also used to determine that the TA of the first cell has been successfully obtained upon receiving feedback information from the network device.

[0259] The terminal device 500 of this application embodiment can implement the corresponding functions of the terminal device in the foregoing method embodiments. The processes, functions, implementation methods, and beneficial effects of each module (sub-module, unit, or component, etc.) in the terminal device 500 can be found in the corresponding descriptions in the above method embodiments, and will not be repeated here. It should be noted that the functions described for each module (sub-module, unit, or component, etc.) in the terminal device 500 of the application embodiment can be implemented by different modules (sub-modules, units, or components, etc.) or by the same module (sub-module, unit, or component, etc.).

[0260] Figure 7 is a schematic block diagram of a first network device 700 according to an embodiment of the present application. The first network device 700 may include:

[0261] The second communication module 710 is used to send a first message to the terminal device; wherein the first network device is the network device of the first cell, and the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0262] In some embodiments, the first message includes a broadcast message.

[0263] In some embodiments, the first message is used to indicate one or more of the following:

[0264] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0265] Whether the first cell and the second cell are synchronized for downlink timing; wherein, the second cell is the source cell or the previous camped cell of the terminal device;

[0266] Downlink timing difference between the first cell and the second cell.

[0267] In some embodiments, the first message includes one or more of the following:

[0268] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0269] Whether the downlink timing synchronization is between the first cell and the second cell;

[0270] Downlink timing difference between the first cell and the second cell;

[0271] Grouping information for candidate cells, neighboring cells, or frequency points;

[0272] Downlink timing difference between different groups;

[0273] A list of cells, frequencies, or groups that have the same downlink timing information as the first cell;

[0274] A list of cells, frequencies, or groups that have different downlink timing information from the first cell;

[0275] Downlink timing difference corresponding to the list of cells, frequency points, or groups that have different downlink timing information from the first cell;

[0276] First indication information for the first cell or the second cell; wherein, the first indication information is used to indicate the group to which the first cell or the second cell belongs.

[0277] In some embodiments, the group information includes a list of cells or a list of frequencies associated with the group.

[0278] In some embodiments, the packet information includes first indication information associated with a cell or frequency point, and cells with the same first indication information value have the same downlink timing information.

[0279] In some embodiments, the second communication module 710 is further configured to:

[0280] Receive data and / or signaling sent by terminal devices;

[0281] Send feedback information to the terminal device; the feedback information is used to confirm that the terminal device has successfully obtained the TA of the first cell.

[0282] The first network device 700 of this application embodiment can realize the corresponding functions of the first network device in the foregoing method embodiments. The processes, functions, implementation methods, and beneficial effects of each module (sub-module, unit, or component, etc.) in the first network device 700 can be found in the corresponding descriptions in the above method embodiments, and will not be repeated here. It should be noted that the functions described for each module (sub-module, unit, or component, etc.) in the first network device 700 of the application embodiment can be implemented by different modules (sub-modules, units, or components, etc.) or by the same module (sub-module, unit, or component, etc.).

[0283] Figure 8 is a schematic block diagram of a second network device 800 according to an embodiment of the present application. The second network device 800 may include:

[0284] The third communication module 810 is used to send a first message to the terminal device; wherein, the second network device is the network device of the second cell, and the second cell is the source cell or the previous camped cell of the terminal device; the first message is used to determine whether the first cell supports obtaining the TA of the first cell through the measurement method of the terminal device.

[0285] In some embodiments, the first message includes an RRC message sent by the second cell.

[0286] In some embodiments, the RRC message is used to instruct the terminal device to switch to the first cell.

[0287] In some embodiments, the first message includes a broadcast message sent by the second cell.

[0288] In some embodiments, the first message is used to indicate one or more of the following:

[0289] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0290] Whether the downlink timing synchronization is between the first cell and the second cell;

[0291] Downlink timing difference between the first cell and the second cell.

[0292] In some embodiments, the first message includes one or more of the following:

[0293] Does the first cell support obtaining the TA of the first cell through measurement by terminal equipment?

[0294] Whether the downlink timing synchronization is between the first cell and the second cell;

[0295] Downlink timing difference between the first cell and the second cell;

[0296] Grouping information for candidate cells, neighboring cells, or frequency points;

[0297] Downlink timing difference between different groups;

[0298] A list of cells, frequencies, or groups that have the same downlink timing information as the second cell;

[0299] A list of cells, frequencies, or groups that have different downlink timing information from the second cell;

[0300] Downlink timing difference corresponding to the list of cells, frequency points, or groups that have different downlink timing information from the second cell;

[0301] First indication information for the first cell or the second cell; wherein, the first indication information is used to indicate the group to which the first cell or the second cell belongs.

[0302] In some embodiments, the group information includes a list of cells or a list of frequencies associated with the group.

[0303] In some embodiments, the packet information includes first indication information associated with a cell or frequency point, and cells with the same first indication information value have the same downlink timing information.

[0304] The second network device 800 in this application embodiment can implement the corresponding functions of the second network device in the foregoing method embodiments. The processes, functions, implementation methods, and beneficial effects of each module (sub-module, unit, or component, etc.) in the second network device 800 can be found in the corresponding descriptions in the above method embodiments, and will not be repeated here. It should be noted that the functions described for each module (sub-module, unit, or component, etc.) in the second network device 800 of this application embodiment can be implemented by different modules (sub-modules, units, or components, etc.) or by the same module (sub-module, unit, or component, etc.).

[0305] Figure 9 is a schematic structural diagram of a communication device 900 according to an embodiment of this application. The communication device 900 includes a processor 910, which can call a computer program from a memory to enable the communication device 900 to implement the methods in the embodiments of this application.

[0306] In one embodiment, the communication device 900 may further include a memory 920. The processor 910 can retrieve computer programs from the memory 920 to enable the communication device 900 to implement the methods described in the embodiments of this application.

[0307] The memory 920 can be a separate device independent of the processor 910, or it can be integrated into the processor 910.

[0308] In one embodiment, the communication device 900 may further include a transceiver 930, which the processor 910 may control to communicate with other devices. Specifically, it may send information or data to other devices or receive information or data sent by other devices.

[0309] The transceiver 930 may include a transmitter and a receiver. The transceiver 930 may further include antennas, and the number of antennas may be one or more.

[0310] In one embodiment, the communication device 900 may be a first network device and / or a second network device in the embodiments of this application, and the communication device 900 may implement the corresponding processes implemented by the first network device and / or the second network device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0311] In one embodiment, the communication device 900 may be a terminal device in the embodiments of this application, and the communication device 900 may implement the corresponding processes implemented by the terminal device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0312] Figure 10 is a schematic structural diagram of a chip 1000 according to an embodiment of this application. The chip 1000 includes a processor 1010, which can call computer programs from memory to implement the methods in the embodiments of this application.

[0313] In one embodiment, chip 1000 may further include memory 1020. Processor 1010 can retrieve computer programs from memory 1020 to implement the methods executed by the terminal device or network device in this embodiment.

[0314] The memory 1020 can be a separate device independent of the processor 1010, or it can be integrated into the processor 1010.

[0315] In one embodiment, the chip 1000 may further include an input interface 1030. The processor 1010 can control the input interface 1030 to communicate with other devices or chips; specifically, it can acquire information or data sent by other devices or chips.

[0316] In one embodiment, the chip 1000 may further include an output interface 1040. The processor 1010 can control the output interface 1040 to communicate with other devices or chips; specifically, it can output information or data to other devices or chips.

[0317] In one implementation, the chip can be applied to the first network device and / or the second network device in the embodiments of this application, and the chip can implement the corresponding processes implemented by the first network device and / or the second network device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0318] In one implementation, the chip can be applied to the terminal device in the embodiments of this application, and the chip can implement the corresponding processes implemented by the terminal device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0319] The chips used in the first network device, the second network device, and the terminal device can be the same chip or different chips.

[0320] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0321] The processors mentioned above can be general-purpose processors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), or other programmable logic devices, transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processors mentioned above can be microprocessors or any conventional processor.

[0322] The aforementioned memory can be volatile memory or non-volatile memory, or a combination of both. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM).

[0323] It should be understood that the above-described memory is exemplary and not a limiting description. For example, the memory in the embodiments of this application may also be static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DR RAM), etc. That is to say, the memory in the embodiments of this application is intended to include, but is not limited to, these and any other suitable types of memory.

[0324] Figure 11 is a schematic block diagram of a communication system 1100 according to an embodiment of the present application. The communication system 1100 includes a terminal device 1110 and a network device 1120.

[0325] The first network device 1120 is used to send a first message to the terminal device; wherein, the first network device is the network device of the first cell, and the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0326] The second network device 1130 is used to send a first message to the terminal device; wherein, the second network device is the network device of the second cell, and the second cell is the source cell or the previous cell of the terminal device; the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device.

[0327] Terminal device 1110 is used to determine the timing advance (TA) of a first cell by measurement when a first condition is met; wherein the first condition includes initiating a first process, the first process being used to access or camp on the first cell.

[0328] Specifically, the terminal device 1110 can be used to implement the corresponding functions implemented by the terminal device in the above method, the first network device 1120 can be used to implement the corresponding functions implemented by the first network device in the above method, and the second network device 1130 can be used to implement the corresponding functions implemented by the second network device in the above method. For the sake of brevity, further details are omitted here.

[0329] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. This computer program product includes one or more computer instructions. When these computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. 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. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

[0330] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0331] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0332] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

An information determination method, comprising: If a first condition is met, the terminal device determines the timing advance (TA) of the first cell by measurement; wherein the first condition includes initiating a first procedure for accessing or camping on the first cell. According to the method of claim 1, wherein, The first process includes one or more of the following: Cell handover; Radio Resource Control (RRC) establishment; RRC recovery; RRC reconstruction; The neighborhood was re-selected. The method according to claim 1 or 2, wherein, The first condition also includes one or more of the following: The second cell's TA is valid; where the second cell is the source cell or the previous stationed cell; The first cell supports obtaining the TA of the first cell through measurement by terminal equipment. The method according to any one of claims 1-3, wherein, The method further includes: If the change in the measurement result of the terminal device in the second cell is less than or equal to the first threshold and / or the timing advance timer (TAT) is in operation, the TA of the second cell is determined to be valid. The method according to claim 4, wherein, The change in the measurement result includes the change between two consecutive measurement results and / or the change between the current measurement result and the measurement result at the time of the last TA update. The method according to claim 4 or 5, wherein, The method further includes: When updating the TA of the second cell, the terminal device restarts the TA. The method according to claim 6, wherein, The method further includes: The terminal device updates the TA of the second cell periodically or based on the triggering of the first event within the second cell. The method according to claim 7, wherein, The first event includes one or more of the following: The measurement result of the second cell is less than the second threshold; The change in the measurement results of two consecutive measurements in the second cell is greater than the third threshold; The position change of the terminal device is greater than the fourth threshold. The terminal device's moving speed is greater than the fifth threshold. The method according to any one of claims 1-8, wherein, The method further includes: The terminal device determines whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device based on the first message sent by the first cell or the second cell. The method according to claim 9, wherein, The first message includes the RRC message sent by the second cell. The method according to claim 10, wherein, The RRC message is used to instruct the terminal device to switch to the first cell. The method according to any one of claims 9-11, wherein, The first message includes broadcast messages sent by the first cell or the second cell. The method according to any one of claims 9-12, wherein, The first message is used to indicate one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell. The method according to any one of claims 9-13, wherein, The terminal device determines whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device based on a first message sent by the first cell or the second cell, including: When the terminal device determines that the downlink timing of the second cell is synchronized with that of the first cell based on the first message, or when it obtains the downlink timing difference between the second cell and the first cell based on the first message, it determines that the first cell supports obtaining the TA of the first cell through measurement by the terminal device. The method according to any one of claims 9-14, wherein, The first message includes one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell; Grouping information for candidate cells, neighboring cells, or frequency points; Downlink timing difference between different groups; A list of cells, frequencies, or groups that have the same downlink timing information as the first cell or the second cell; A list of cells, frequencies, or groups that have different downlink timing information from the first cell or the second cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the first cell or the second cell; The first indication information of the first cell or the second cell; wherein the first indication information is used to indicate the group to which the first cell or the second cell is located. The method according to claim 15, wherein, The group information includes a list of cells or a list of frequencies associated with the group. The method according to claim 15, wherein, The grouping information includes first indication information associated with a cell or frequency point, and cells with the same value of the first indication information have the same downlink timing information. The method according to any one of claims 15-17, wherein, The method further includes: When the terminal device determines that the second cell and the first cell belong to the same group based on the first message, it determines that the downlink timing of the second cell and the first cell is synchronized. The method according to any one of claims 1-18, wherein, The method further includes: If the terminal device successfully obtains the TA of the first cell, it restarts the TAT. The method according to any one of claims 1-19, wherein, The method further includes: If the terminal device fails to obtain the TA of the first cell, and / or fails to obtain downlink timing synchronization information or downlink timing difference between the first cell and the second cell, it shall stop TAT. The method according to any one of claims 1-18, wherein, The method further includes: If the terminal device successfully obtains the TA of the first cell, it initiates the TAT associated with the first cell. The method according to claim 21, wherein, The method further includes: The terminal device stores the TA of the second cell and keeps the TAT associated with the second cell running. The method according to any one of claims 1-22, wherein, The method further includes: After determining the TA of the first cell by measurement, the terminal device sends data and / or signaling to the network device of the first cell. Upon receiving feedback information from the network device, the terminal device determines that it has successfully obtained the TA of the first cell. An information determination method, comprising: A first network device sends a first message to a terminal device; wherein the first network device is a network device of a first cell, and the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device. The method according to claim 24, wherein, The first message includes broadcast messages. The method according to claim 24 or 25, wherein, The first message is used to indicate one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; wherein, the second cell is the source cell or the previous cell of the terminal device; Downlink timing difference between the first cell and the second cell. The method according to any one of claims 24-26, wherein, The first message includes one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell; Grouping information for candidate cells, neighboring cells, or frequency points; Downlink timing difference between different groups; A list of cells, frequencies, or groups that have the same downlink timing information as the first cell; A list of cells, frequencies, or groups that have different downlink timing information from the first cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the first cell; The first indication information of the first cell or the second cell; wherein the first indication information is used to indicate the group to which the first cell or the second cell is located. The method according to claim 27, wherein, The group information includes a list of cells or a list of frequencies associated with the group. The method according to claim 27, wherein, The grouping information includes first indication information associated with a cell or frequency point, and cells with the same value of the first indication information have the same downlink timing information. The method according to any one of claims 24-27, wherein, The method further includes: The first network device receives data and / or signaling sent by the terminal device; The first network device sends feedback information to the terminal device; wherein, the feedback information is used to determine that the terminal device has successfully acquired the TA of the first cell. An information determination method, comprising: The second network device sends a first message to the terminal device; wherein, the second network device is the network device of the second cell, and the second cell is the source cell or the previous cell of the terminal device; the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device. The method according to claim 31, wherein, The first message includes the RRC message sent by the second cell. The method according to claim 32, wherein, The RRC message is used to instruct the terminal device to switch to the first cell. The method according to any one of claims 31-33, wherein, The first message includes broadcast messages sent by the second cell. The method according to any one of claims 31-34, wherein, The first message is used to indicate one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell. The method according to any one of claims 31-35, wherein, The first message includes one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell; Grouping information for candidate cells, neighboring cells, or frequency points; Downlink timing difference between different groups; A list of cells, frequencies, or groups that have the same downlink timing information as the second cell; A list of cells, frequencies, or groups that have different downlink timing information from the second cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the second cell; The first indication information of the first cell or the second cell; wherein the first indication information is used to indicate the group to which the first cell or the second cell is located. The method according to claim 36, wherein, The group information includes a list of cells or a list of frequencies associated with the group. The method according to claim 36, wherein, The grouping information includes first indication information associated with a cell or frequency point, and cells with the same value of the first indication information have the same downlink timing information. A terminal device, comprising: A first processing module is configured to determine the TA of a first cell by measurement when a first condition is met; wherein the first condition includes initiating a first process, the first process being used to access or camp on the first cell. The terminal device according to claim 39, wherein, The first process includes one or more of the following: Cell handover; RRC established; RRC recovery; RRC reconstruction; The neighborhood was re-selected. The terminal device according to claim 39 or 40, wherein, The first condition also includes one or more of the following: The second cell's TA is valid; where the second cell is the source cell or the previous stationed cell; The first cell supports obtaining the TA of the first cell through measurement by terminal equipment. The terminal device according to any one of claims 39-41, wherein, The first processing module is further configured to: If the change in the measurement result of the second cell is less than or equal to the first threshold and / or the TAT is in operation, the TA of the second cell is determined to be valid. The terminal device according to claim 42, wherein, The change in the measurement result includes the change between two consecutive measurement results and / or the change between the current measurement result and the measurement result at the time of the last TA update. The terminal device according to claim 42 or 43, wherein, The first processing module is further configured to: When updating the TA of the second cell, the TA is restarted. The terminal device according to claim 44, wherein, The first processing module is further configured to: Within the second cell, the TA of the second cell is updated periodically or based on the triggering of the first event. The terminal device according to claim 45, wherein, The first event includes one or more of the following: The measurement result of the second cell is less than the second threshold; The change in the measurement results of two consecutive measurements in the second cell is greater than the third threshold; The position change of the terminal device is greater than the fourth threshold. The terminal device's moving speed is greater than the fifth threshold. The terminal device according to any one of claims 39-46, wherein, The first processing module is further configured to: Based on the first message sent by the first cell or the second cell, determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device. The terminal device according to claim 47, wherein, The first message includes the RRC message sent by the second cell. The terminal device according to claim 48, wherein, The RRC message is used to instruct the terminal device to switch to the first cell. The terminal device according to any one of claims 47-49, wherein, The first message includes broadcast messages sent by the first cell or the second cell. The terminal device according to any one of claims 47-50, wherein, The first message is used to indicate one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell. The terminal device according to any one of claims 47-51, wherein, The first processing module is further configured to: If the downlink timing synchronization between the second cell and the first cell is determined based on the first message, or if the downlink timing difference between the second cell and the first cell is obtained based on the first message, it is determined that the first cell supports obtaining the TA of the first cell through measurement by the terminal device. The terminal device according to any one of claims 47-52, wherein, The first message includes one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell; Grouping information for candidate cells, neighboring cells, or frequency points; Downlink timing difference between different groups; A list of cells, frequencies, or groups that have the same downlink timing information as the first cell or the second cell; A list of cells, frequencies, or groups that have different downlink timing information from the first cell or the second cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the first cell or the second cell; The first indication information of the first cell or the second cell; wherein the first indication information is used to indicate the group to which the first cell or the second cell is located. The terminal device according to claim 53, wherein, The group information includes a list of cells or a list of frequencies associated with the group. The terminal device according to claim 53, wherein, The grouping information includes first indication information associated with a cell or frequency point, and cells with the same value of the first indication information have the same downlink timing information. The terminal device according to any one of claims 53-55, wherein, The first processing module is further configured to: If it is determined from the first message that the second cell and the first cell belong to the same group, then the downlink timing synchronization between the second cell and the first cell is determined. The terminal device according to any one of claims 39-56, wherein, The first processing module is further configured to: If the TA of the first cell is successfully obtained, restart the TAT. The terminal device according to any one of claims 39-57, wherein, The first processing module is further configured to: If the TA of the first cell is not successfully obtained, and / or if the downlink timing synchronization information or downlink timing difference between the first cell and the second cell is not obtained, the TAT shall be stopped. The terminal device according to any one of claims 39-56, wherein, The first processing module is further configured to: If the TA of the first cell is successfully obtained, the TAT associated with the first cell is started. The terminal device according to claim 59, wherein, The first processing module is further configured to: Store the TA of the second cell and keep the TAT associated with the second cell running. The terminal device according to any one of claims 39-60, wherein, The terminal device further includes a first communication module: The first communication module is used to send data and / or signaling to the network equipment of the first cell after determining the TA of the first cell through measurement; The first processing module is further configured to determine, upon receiving feedback information from the network device, that the TA of the first cell has been successfully acquired. A first network device includes: The second communication module is used to send a first message to the terminal device; wherein the first network device is the network device of the first cell, and the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device. The first network device according to claim 62, wherein, The first message includes broadcast messages. The first network device according to claim 62 or 63, wherein, The first message is used to indicate one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; wherein, the second cell is the source cell or the previous cell of the terminal device; Downlink timing difference between the first cell and the second cell. The first network device according to any one of claims 62-64, wherein, The first message includes one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell; Grouping information for candidate cells, neighboring cells, or frequency points; Downlink timing difference between different groups; A list of cells, frequencies, or groups that have the same downlink timing information as the first cell; A list of cells, frequencies, or groups that have different downlink timing information from the first cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the first cell; The first indication information of the first cell or the second cell; wherein the first indication information is used to indicate the group to which the first cell or the second cell is located. The first network device according to claim 65, wherein, The group information includes a list of cells or a list of frequencies associated with the group. The first network device according to claim 65, wherein, The grouping information includes first indication information associated with a cell or frequency point, and cells with the same value of the first indication information have the same downlink timing information. The first network device according to any one of claims 62-67, wherein, The second communication module is also used for: Receive data and / or signaling sent by the terminal device; Send feedback information to the terminal device; wherein the feedback information is used to determine that the terminal device has successfully obtained the TA of the first cell. A second network device, comprising: The third communication module is used to send a first message to the terminal device; wherein the second network device is the network device of the second cell, and the second cell is the source cell or the previous camped cell of the terminal device; the first message is used to determine whether the first cell supports obtaining the TA of the first cell through measurement by the terminal device. The second network device according to claim 69, wherein, The first message includes the RRC message sent by the second cell. The second network device according to claim 70, wherein, The RRC message is used to instruct the terminal device to switch to the first cell. The second network device according to any one of claims 69-71, wherein, The first message includes broadcast messages sent by the second cell. The second network device according to any one of claims 69-72, wherein, The first message is used to indicate one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell. The second network device according to any one of claims 69-73, wherein, The first message includes one or more of the following: Does the first cell support obtaining the TA of the first cell through measurement by a terminal device? Whether the first cell and the second cell are synchronized for downlink timing; Downlink timing difference between the first cell and the second cell; Grouping information for candidate cells, neighboring cells, or frequency points; Downlink timing difference between different groups; A list of cells, frequencies, or groups that have the same downlink timing information as the second cell; A list of cells, frequencies, or groups that have different downlink timing information from the second cell, and a downlink timing difference corresponding to the list of cells, frequencies, or groups that have different downlink timing information from the second cell; First indication information for the first cell or the second cell; wherein, the first indication information is used to indicate the first cell or The group to which the second cell belongs. The second network device according to claim 74, wherein, The group information includes a list of cells or a list of frequencies associated with the group. The second network device according to claim 74, wherein, The grouping information includes first indication information associated with a cell or frequency point, and cells with the same value of the first indication information have the same downlink timing information. A terminal device, comprising: A transceiver, a processor, and a memory, wherein the memory is used to store a computer program, the transceiver is used to communicate with other devices, and the processor is used to invoke the computer program stored in the memory to cause the terminal device to perform the method as described in any one of claims 1 to 23. A first network device includes: A transceiver, a processor, and a memory, wherein the memory is used to store a computer program, the transceiver is used to communicate with other devices, and the processor is used to invoke the computer program stored in the memory to cause the first network device to perform the method as described in any one of claims 24 to 30. A second network device, comprising: A transceiver, a processor, and a memory, wherein the memory is used to store a computer program, the transceiver is used to communicate with other devices, and the processor is used to invoke the computer program stored in the memory to cause the second network device to perform the method as described in any one of claims 31 to 38. A chip, comprising: A processor for calling a computer program from memory, causing a device on which the chip is mounted to perform the method as described in any one of claims 1 to 23. A chip, comprising: A processor for calling a computer program from memory, causing a device on which the chip is mounted to perform the method as described in any one of claims 24 to 30. A chip, comprising: A processor for calling a computer program from memory, causing a device on which the chip is mounted to perform the method as described in any one of claims 31 to 38. A computer-readable storage medium for storing a computer program that, when run by a device, causes the device to perform the method as described in any one of claims 1 to 23. A computer-readable storage medium for storing a computer program that, when run by a device, causes the device to perform the method as described in any one of claims 24 to 30. A computer-readable storage medium for storing a computer program that, when run by a device, causes the device to perform the method as described in any one of claims 31 to 38. A computer program product includes computer program instructions that cause a computer to perform the method as described in any one of claims 1 to 23. A computer program product includes computer program instructions that cause a computer to perform the method as described in any one of claims 24 to 30. A computer program product includes computer program instructions that cause a computer to perform the method as described in any one of claims 31 to 38. A computer program that causes a computer to perform the method as described in any one of claims 1 to 23. A computer program that causes a computer to perform the method as described in any one of claims 24 to 30. A computer program that causes a computer to perform the method as described in any one of claims 31 to 38. A communication system, comprising: A terminal device for performing the method as described in any one of claims 1 to 23; A first network device is configured to perform the method as described in any one of claims 24 to 30; A second network device is configured to perform the method as described in any one of claims 31 to 38.

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