A communication method and a communication device

Abstract

The application provides a communication method and a communication device, which are applied to the technical field of communication. In the communication method, a terminal device can receive an activation instruction of a TCI state of a target network device sent by a service network device before sending a cell switching instruction, so as to activate the TCI state. The terminal device can track TRS sent by the target network device based on the TCI state according to a predetermined tracking mode. The predetermined tracking mode is determined from a plurality of preset tracking modes, and in any tracking mode of the plurality of preset tracking modes, the earliest sending time of the TRS is later than the sending time of the activation instruction. The communication method can avoid resource waste caused by the target network device sending the TRS too early, and at the same time, ensure that the terminal can quickly use the TRS for accurate synchronization in the switching key stage, effectively balancing the switching performance and resource efficiency.

Description

Technical Field

[0001] This application relates to the field of communication technology, and more specifically, to a communication method and a communication device. Background Technology

[0002] In modern wireless communication systems (such as 5G NR), cell handover is a crucial technology to ensure communication continuity for mobile terminal devices. To achieve smooth and fast handover, terminals need to synchronize their signals with the target cell (or "candidate cell") in advance. The tracking reference signal (TRS) is a more accurate reference signal than the synchronization signal block (SSB), and using TRS for tracking significantly improves synchronization accuracy and handover performance. In Rel-18, while it is recommended to use TRS for signal tracking as early as possible, a problem exists: the candidate cell is unaware whether the TRS transmitted to terminal devices connected to it is being monitored by terminal devices connected to neighboring cells. This prevents the candidate cell from pausing TRS transmission, resulting in poor handover performance and wasted resources.

[0003] To address the aforementioned issues, existing solutions either save resources but suffer from low switching performance, or guarantee switching performance but waste resources, failing to simultaneously meet the two key requirements of high switching performance and high resource efficiency. Summary of the Invention

[0004] This application provides a communication method and communication device that enables the simultaneous fulfillment of two key requirements—high handover performance and high resource efficiency—during cell handover.

[0005] In a first aspect, a communication method is provided. This method can be executed by a terminal device, or by a component (such as a circuit, chip, or chip system) configured in the terminal device, or by a logic module or software capable of implementing all or part of the functions of the terminal device. In this first aspect and its possible implementations, the communication method is described as being executed by a terminal device.

[0006] The method includes: receiving an activation instruction for the transmission configuration indicator (TCI) status of a target network device sent by a serving network device of the terminal device; activating the TCI status; and tracking a tracking reference signal (TRS) sent by the target network device based on the TCI status according to a predetermined tracking mode. The target network device is the network device that the terminal device will switch to. For example, the target network device can be the most suitable candidate network device selected by the serving network device from multiple candidate network devices. After the serving network device selects the target network device, it can instruct the terminal device to activate the TCI status of the target network device, allowing the terminal device to know the target network device it will switch to.

[0007] The activation command is received earlier than the cell handover command is sent. This allows the terminal device to prepare for tracking TRS as soon as it receives the cell handover command. Compared to activating the TCI state of the target network device only after receiving the cell handover command, the handover performance is better.

[0008] The predetermined tracking mode is selected from a variety of preset tracking modes, and in any of these preset tracking modes, the earliest transmission time of the TRS signal is later than the transmission time of the activation command. In other words, this application supports multiple preset tracking modes, and the most suitable preset tracking mode can be selected for TRS tracking each time according to the actual situation. Therefore, it has good adaptability and robustness to different wireless scenarios and service requirements. Furthermore, regardless of the preset tracking mode, the earliest transmission time of the TRS signal is always later than the transmission time of the activation command, avoiding premature transmission of the TRS signal and thus avoiding resource waste.

[0009] In summary, the above scheme activates the TCI state before the cell handover process is completed, and the terminal device does not immediately track the TRS after activating the TCI state. Instead, it triggers tracking under specific conditions based on a pre-determined tracking mode suitable for the current situation. This achieves delayed activation of TRS tracking (or decoupling of TRS configuration and physical transmission), thereby avoiding resource waste caused by the target network device sending the TRS too early. At the same time, it ensures that the terminal can quickly use the TRS for accurate synchronization during the critical handover phase, effectively balancing handover performance and resource efficiency. It also has good adaptability and robustness to different wireless scenarios and services.

[0010] In an optional implementation, the predetermined tracking mode is a tracking mode determined and specified by the serving network device from a variety of preset tracking mechanisms.

[0011] In the above scheme, the service network device, as the core control node on the network side, can obtain more comprehensive global information. Therefore, by having the service network device determine and specify the tracking mode from a variety of preset tracking mechanisms, it can ensure that the selected mode is highly adapted to the current communication scenario, thereby more accurately balancing switching performance and resource efficiency.

[0012] In an optional implementation, the predetermined tracking mode is the tracking mode determined by the terminal device from a variety of preset tracking modes.

[0013] In the above scheme, the terminal device, as the direct user of the communication service, has the most intuitive and timely perception of its own real-time status. Therefore, the terminal device can autonomously determine the tracking mode from a variety of preset tracking modes, which allows the terminal to flexibly adjust according to its own actual situation. This not only reduces the decision-making pressure and signaling interaction overhead of the service network equipment, but also makes the selection of tracking mode more in line with the real-time needs of the terminal.

[0014] In an optional implementation, if the predetermined tracking mode is determined by the serving network device, before receiving the activation instruction for the Transmission Configuration Indication (TCI) status of the target network device sent by the serving network device to the terminal device, the method further includes: receiving tracking indication information sent by the serving network device. The tracking indication information is used to indicate the predetermined tracking mode.

[0015] In the above scheme, when the serving network device determines the tracking mode, the terminal device determines the tracking mode by receiving tracking instruction information in advance. This allows the terminal device to understand the subsequent tracking logic before receiving the TCI state activation command and prepare for tracking in advance. This advance notification method avoids the delay caused by the terminal device temporarily determining the tracking mode after activating the TCI state, ensuring that the terminal device can quickly and accurately track the TRS when the triggering conditions are met. This further guarantees the timeliness and smoothness of the handover, reduces handover latency, and improves the user communication experience.

[0016] In an optional implementation, the tracking indication information is carried in radio resource control (RRC) signaling.

[0017] In the above scheme, by utilizing existing RRC signaling to transmit tracking indication information, there is no need to establish a new signaling transmission channel, which reduces implementation complexity, improves the efficiency and reliability of signaling transmission, and maintains compatibility with existing protocols.

[0018] In an optional implementation, the tracking indication information is carried in the RRC reconfiguration message.

[0019] In the above scheme, by utilizing the existing RRC reconfiguration message passing trace indication information, there is no need to establish a new signaling transmission channel, which reduces the implementation complexity, improves the efficiency and reliability of signaling transmission, and maintains compatibility with existing protocols.

[0020] In an optional implementation, the RRC reconfiguration message includes TCI status configuration information, which includes quasi-co-address information and carries tracking indication information.

[0021] In the above scheme, since the quasi-co-address information is directly associated with the signal association logic required for TRS tracking, the tracking indication information is embedded in it, which can realize the coordinated transmission of TCI status configuration, quasi-co-address signal and tracking mode indication, avoid information asynchrony caused by multiple signaling being sent in a scattered manner, and ensure that the terminal device can obtain the complete logic at one time when receiving TRS tracking-related configuration.

[0022] In an optional implementation, when the predetermined tracking mode is a cell handover instruction triggering mode, the target network device's TRS is tracked based on the TCI state according to the predetermined tracking mode, including: receiving a cell handover instruction; and tracking the TRS based on the TCI state, wherein the TRS is issued by the target network device based on a cell handover request.

[0023] In the above-mentioned cell handover command-triggered mode, the terminal device does not immediately track the TCI state after activating it, thereby avoiding the waste of terminal device resources and improving network resource utilization. At the same time, the terminal device activates the TCI state in advance to prepare, and quickly and accurately tracks the TRS after the cell handover command is issued, thereby avoiding the synchronization delay and handover failure risk of relying on SSB, and ensuring handover performance and communication continuity.

[0024] In an optional implementation, when the predetermined tracking mode is the emergency trigger mode, the TRS sent by the target network device based on the TCI state is tracked according to the predetermined tracking mode. This includes: when a cell handover command is received or an abnormal signal quality of the serving network device is detected, the target network device sends a TRS in response to a cell handover request sent by the serving network device based on the TCI state. The cell handover request is sent simultaneously with or after the activation command but before the activation of the TCI state.

[0025] In the aforementioned emergency trigger mode, the logic of tracking TRS based on cell handover instructions is retained to ensure performance in normal handover scenarios, while an emergency tracking mechanism is added for situations with abnormal signal quality. When sudden situations such as a sudden deterioration of the serving network equipment signal occur, the terminal device can promptly and accurately track the signal through TRS, avoiding handover failures or communication interruptions caused by the inability to synchronize in a timely manner. This improves the robustness of the communication system in sudden link failure scenarios and ensures the continuity of communication for users in complex wireless environments.

[0026] In an optional implementation, signal quality anomalies include: signal quality being less than a quality threshold, or the rate of change of signal quality being greater than a rate of change threshold.

[0027] The above scheme clearly defines the judgment criteria for signal quality anomalies, enabling the terminal to accurately trigger the emergency tracking mechanism, avoiding false triggering or missed triggering due to ambiguous judgment criteria, ensuring timely response when emergency tracking TRS is truly needed, further improving the accuracy and reliability of the emergency triggering mode, and ensuring the success rate of handover and communication continuity in scenarios with abnormal signal quality.

[0028] In an optional implementation, when the predetermined tracking mode is a request-triggered mode, the tracking of the TRS sent by the target network device based on the TCI state, according to the predetermined tracking mode, includes: receiving a cell handover instruction; sending a TRS transmission activation request signal to the target network device; and tracking the TRS based on the TCI state. The TRS is issued in response to the TRS transmission activation request signal.

[0029] In the aforementioned request-triggered mode, the target network device only sends a TRS after receiving an activation request from the terminal device. This allows the terminal to activate TRS transmission on demand, avoiding resource waste caused by the target network device sending a TRS when the terminal device is not ready to receive it. At the same time, it ensures that the terminal device can accurately receive and track the TRS after sending the request, reducing resource loss caused by the asynchrony between TRS transmission and terminal reception, and improving network resource utilization and handover accuracy.

[0030] In an optional implementation, sending a TRS transmission activation request signal to the target network device includes: sending the TRS transmission activation request signal on the physical uplink control channel (PUCCH) resource associated with the target network device.

[0031] In the above scheme, PUCCH, as a channel dedicated to transmitting uplink control information, has the characteristics of low transmission latency and high reliability. By using the PUCCH associated with the target network device to send an activation request signal, it can ensure that the request signal is transmitted to the target network device quickly and reliably, reduce the transmission latency of the request signal, and enable the target network device to respond to the request and send TRS in a timely manner.

[0032] Secondly, a communication method is provided, which can be executed by a network device, or by a component (such as a circuit, chip, or chip system) configured in the network device, or by a logic module or software capable of implementing all or part of the functions of a terminal device. In this second aspect and its possible implementations, the example of the communication method being executed by the serving network device of the terminal device is described.

[0033] The method includes: sending an activation command for the Transmission Configuration Indicator (TCI) status of the target network device to a terminal device communicating with the serving network device; sending a cell handover request and identification information of a pre-determined tracking mode to the target network device; and, upon receiving a successful cell handover response from the target network device, sending a cell handover command to the terminal device. The target network device is the network device to which the terminal device will hand over, and the pre-determined tracking mode is one selected from multiple preset tracking modes, wherein at least two preset tracking modes have different transmission timings for their corresponding Tracking Reference Signals (TRS).

[0034] In the above scheme, the serving network device informs the target network device of the tracking mode in advance, enabling the target network device to prepare for TRS transmission and avoiding TRS transmission delays caused by information asynchrony. Simultaneously, activation and handover commands are sent in stages to ensure coordinated actions between the terminal device and the target network device during the handover process. Therefore, by coordinating the behavior of the terminal device and the target network device through the serving network device, flexible configuration and triggering of the TRS tracking mode are achieved, ensuring that TRS is sent only when necessary during the handover process, improving resource utilization, and guaranteeing a smooth handover.

[0035] In an optional implementation, the pre-determined tracking mode is the tracking mode selected and specified by the serving network device from a variety of preset tracking mechanisms. In the above scheme, the serving network device, as the core control node on the network side, can obtain more comprehensive global information. Therefore, having the serving network device select and specify the tracking mode from a variety of preset tracking mechanisms ensures that the selected mode is highly adapted to the current communication scenario, thereby more accurately balancing switching performance and resource efficiency.

[0036] In an optional implementation, the predetermined tracking mode is the tracking mode selected by the terminal device from a variety of preset tracking modes. In the above scheme, the terminal device, as the direct user of the communication service, has the most intuitive and timely perception of its own real-time status. Therefore, allowing the terminal device to autonomously determine the tracking mode from a variety of preset tracking modes allows the terminal to flexibly adjust according to its own actual situation. This not only reduces the decision-making pressure and signaling interaction overhead of the service network equipment, but also makes the selection of the tracking mode more in line with the real-time needs of the terminal.

[0037] In an optional implementation, if the predetermined tracking mode is determined by the serving network device, the method further includes: determining the predetermined tracking mode from a variety of preset tracking modes based on one or more of the terminal device's wireless channel and link quality information, terminal information, service type, network topology information, and historical data.

[0038] In the above scheme, the service network equipment can comprehensively consider multi-dimensional information to ensure that the selected tracking mode is highly matched with the current communication scenario, maximize the advantages of different tracking modes, and improve switching performance and resource utilization.

[0039] In an optional implementation, if the predetermined tracking mode is determined by the serving network device, before sending an activation instruction for the Transmission Configuration Indication (TCI) state of the target network device to the terminal device communicating with the serving network device, the method further includes: sending tracking indication information to the terminal device. The tracking indication information is used to indicate the predetermined tracking mode, and the tracking indication information corresponds to identification information to ensure that the tracking mode indicated to the terminal device and the tracking mode indicated to the target network device are the same.

[0040] In the above scheme, the serving network device sends tracking indication information to the terminal device before sending the TCI state activation command. This, combined with the terminal device's advance receipt and parsing of the tracking indication information, achieves advance synchronization of tracking mode information. This advance synchronization ensures that the terminal device has already defined the tracking logic when activating the TCI state, eliminating the need to temporarily acquire tracking mode information after activation. This avoids the impact of information acquisition delays on TRS tracking, enabling the terminal device to respond quickly when the triggering conditions are met, ensuring timely and smooth handover, and reducing the risk of communication interruption during the handover process.

[0041] In an optional implementation, the tracking indication information is carried in radio resource control (RRC) signaling.

[0042] In the above scheme, by utilizing existing RRC signaling to transmit tracking indication information, there is no need to establish a new signaling transmission channel, which reduces implementation complexity, improves the efficiency and reliability of signaling transmission, and maintains compatibility with existing protocols.

[0043] In an optional implementation, the tracking indication information is carried in the Radio Resource Control (RRC) reconfiguration message.

[0044] In the above scheme, by utilizing the existing RRC reconfiguration message passing trace indication information, there is no need to establish a new signaling transmission channel, which reduces the implementation complexity, improves the efficiency and reliability of signaling transmission, and maintains compatibility with existing protocols.

[0045] In an optional implementation, the RRC reconfiguration message includes TCI status configuration information, which includes quasi-co-address information and carries tracking indication information.

[0046] In the above scheme, since the quasi-co-address information is directly associated with the signal association logic required for TRS tracking, the tracking indication information is embedded in it, which can realize the coordinated transmission of TCI status configuration, quasi-co-address signal and tracking mode indication, avoid information asynchrony caused by multiple signaling being sent in a scattered manner, and ensure that the terminal device can obtain the complete logic at one time when receiving TRS tracking-related configuration.

[0047] In an optional implementation, the cell handover request and identification information are carried in the HANDOVER REQUEST message.

[0048] In the above scheme, by reusing the existing HANDOVER REQUEST message to transmit tracking mode information, signaling complexity and latency are reduced, ensuring that the target network device is informed of the tracking mode in a timely manner, which facilitates its preparation for TRS transmission.

[0049] In an optional implementation, when the predetermined tracking mode is a cell handover command-triggered mode, the identification information is used to instruct the target network device to prepare to send a TRS. Simultaneously or subsequently, the method further includes sending first triggering information to the target network device. The first triggering information is used to trigger the target network device to send a TRS.

[0050] In the cell handover command-triggered mode, the identification information instructs the target network device to prepare for TRS transmission, thereby realizing phased control of TRS transmission. The target network device prepares in advance and accurately sends the TRS after receiving the trigger information, avoiding the waste of resources caused by the target network device sending the TRS too early. It also ensures that the terminal device can receive the TRS in time for tracking after receiving the cell handover command, achieving a balance between resource efficiency and handover performance, and further improving the practicality and effectiveness of the cell handover command-triggered mode.

[0051] In an optional implementation, the first trigger information is carried in the SN STATUS TRANSFER message.

[0052] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the first triggering information.

[0053] In an optional implementation, when the predetermined tracking mode is an emergency trigger mode, the identification information is used to trigger the target network device to send a TRS. Simultaneously or subsequently, the method further includes sending second trigger information to the target network device. The second trigger information is used to trigger the target network device to continue sending TRS.

[0054] In emergency trigger mode, the identification information triggers the target network device to send a TRS, thereby ensuring that the target network device can send a TRS in advance in emergency scenarios, providing a guarantee for rapid tracking when the terminal device detects abnormal signal quality. At the same time, the second trigger information ensures that the TRS can be continuously transmitted after the handover command is issued, meeting the tracking needs of the terminal device during the handover process, avoiding handover failure due to TRS interruption, further enhancing the stability and reliability of the communication system in emergency trigger mode, and ensuring the continuity of user communication.

[0055] In an optional implementation, the second triggering information is carried in the SN STATUS TRANSFER message.

[0056] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the second triggering information.

[0057] In an optional implementation, signal quality anomalies include: signal quality being less than a quality threshold, or the rate of change of signal quality being greater than a rate of change threshold.

[0058] The above scheme clearly defines the judgment criteria for signal quality anomalies, enabling the terminal to accurately trigger the emergency tracking mechanism, avoiding false triggering or missed triggering due to ambiguous judgment criteria, ensuring timely response when emergency tracking TRS is truly needed, further improving the accuracy and reliability of the emergency triggering mode, and ensuring the success rate of handover and communication continuity in scenarios with abnormal signal quality.

[0059] In an optional implementation, when the predetermined tracking mode is a request-triggered mode, the identification information is used to instruct the target network device to prepare for sending a TRS. Simultaneously or subsequently, the method further includes sending third triggering information to the target network device. The third triggering information instructs the target network device to continue preparing for sending a TRS, so as to send a TRS when a TRS transmission activation request signal is detected from the terminal device.

[0060] In request-triggered mode, the identification information instructs the target network device to prepare for TRS transmission. This allows the serving network device to further confirm the target network device's readiness status through third-party triggering information, ensuring that the target network device remains ready during the phase when the terminal device may send a request. This avoids the inability to respond to terminal requests in a timely manner due to the target network device canceling its preparation. Simultaneously, combined with the terminal device's request mechanism, on-demand TRS transmission is achieved, maximizing resource utilization and ensuring the smooth operation of request-triggered mode.

[0061] In an optional implementation, the third triggering information is carried in the SN STATUS TRANSFER message.

[0062] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the third triggering information.

[0063] The second aspect is the implementation on the service network device side, which corresponds to the first aspect. The explanations, supplements, and descriptions of the beneficial effects of the first aspect also apply to the second aspect, and will not be repeated here.

[0064] Thirdly, a communication method is provided, which can be executed by a network device, or by a component (such as a circuit, chip, or chip system) configured in the network device, or by a logic module or software capable of implementing all or part of the functions of a terminal device. In this third aspect and its possible implementations, the example of the communication method being executed by the target network device to which the terminal device is to be switched is described.

[0065] The method includes: receiving a cell handover request and identification information of a predetermined tracking mode sent by the serving network device of the terminal device; and sending a Tracking Reference Signal (TRS) according to the predetermined tracking mode. The predetermined tracking mode is one selected from a variety of preset tracking modes, and at least two preset tracking modes have different timings for sending the TRS.

[0066] In the above scheme, the target network device can flexibly adjust the timing of TRS transmission according to the received tracking mode identifier, ensuring that TRS is sent only when necessary, avoiding TRS transmission chaos caused by missing information, providing reliable support for TRS tracking of terminal devices, ensuring synchronization accuracy during handover, improving handover success rate, and reducing handover latency.

[0067] In an optional implementation, the predetermined tracking mode is a tracking mode determined and specified by the serving network device from a variety of preset tracking mechanisms.

[0068] In the above scheme, the service network device, as the core control node on the network side, can obtain more comprehensive global information. Therefore, by having the service network device determine and specify the tracking mode from a variety of preset tracking mechanisms, it can ensure that the selected mode is highly adapted to the current communication scenario, thereby more accurately balancing switching performance and resource efficiency.

[0069] In an optional implementation, the predetermined tracking mode is the tracking mode determined by the terminal device from a variety of preset tracking modes.

[0070] In the above scheme, the terminal device, as the direct user of the communication service, has the most intuitive and timely perception of its own real-time status. Therefore, the terminal device can autonomously determine the tracking mode from a variety of preset tracking modes, which allows the terminal to flexibly adjust according to its own actual situation. This not only reduces the decision-making pressure and signaling interaction overhead of the service network equipment, but also makes the selection of tracking mode more in line with the real-time needs of the terminal.

[0071] In an optional implementation, the cell handover request and identification information are carried in the HANDOVER REQUEST message.

[0072] In the above scheme, by reusing the existing HANDOVER REQUEST message to transmit tracking mode information, signaling complexity and latency are reduced, ensuring that the target network device is informed of the tracking mode in a timely manner, which facilitates its preparation for TRS transmission.

[0073] In an optional implementation, when the predetermined tracking mode is a cell handover instruction triggering mode, sending a TRS according to the predetermined tracking mode includes: preparing to send a TRS in response to identification information; receiving first trigger information sent by the serving network device; and sending a TRS in response to the first trigger information. The sending time of the first trigger information is later than or equal to the time when the serving network device sends a cell handover instruction to the terminal device.

[0074] In the cell handover command-triggered mode, the target network device first responds to the identification information to prepare for TRS transmission, and then sends the TRS after receiving the first trigger information. This prevents the target network device from sending the TRS prematurely, avoiding resource waste when the terminal device is not ready to receive it. At the same time, the TRS is sent immediately after receiving the first trigger information, ensuring that the terminal device can obtain the TRS in a timely manner for tracking when it receives the cell handover command. This achieves precise synchronization between TRS transmission and terminal reception, balances resource efficiency and handover performance, and improves the operating efficiency of the cell handover command-triggered mode.

[0075] In an optional implementation, the first trigger information is carried in the SN STATUS TRANSFER message.

[0076] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the first triggering information.

[0077] In an optional implementation, if the predetermined tracking mode is an emergency trigger mode, sending a TRS according to the predetermined tracking mode includes: sending a TRS in response to identification information.

[0078] In emergency trigger mode, the target network device immediately sends a TRS response identification information, thus enabling the target network device to quickly provide a TRS in emergency scenarios, providing a guarantee for emergency tracking when the terminal device detects abnormal signal quality of the serving network device.

[0079] In an optional implementation, after sending a TRS in response to the identification information, sending a TRS according to a predetermined tracking mode further includes: if the handover is successful, receiving a second triggering message sent by the serving network device and continuing to send a TRS.

[0080] In emergency trigger mode, after a successful handover, the target network device receives the second trigger information and continues to send TRS, thereby meeting the synchronization needs of the terminal device in the early stage of the handover, ensuring that the terminal device can stably and continuously track the TRS, guaranteeing the communication stability after the handover, and reducing the risk of communication interruption caused by synchronization problems after the handover.

[0081] In an optional implementation, sending TRS according to a predetermined tracking mode further includes: stopping sending TRS in the event of a switching failure.

[0082] In the above scheme, if the handover fails, the target network device stops sending TRS, thus avoiding the waste of resources caused by continuing to send TRS when the handover cannot be completed normally.

[0083] In an optional implementation, the second triggering information is carried in the SN STATUS TRANSFER message.

[0084] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the second triggering information.

[0085] In an optional implementation, when the predetermined tracking mode is a request-triggered mode, sending a TRS according to the predetermined tracking mode includes: preparing to send a TRS in response to identification information; listening for whether a TRS transmission activation request signal sent by the terminal device is received; and sending a TRS when a TRS transmission activation request signal is received.

[0086] In request-triggered mode, the target network device prepares its response identification information and sends a TRS when it hears a terminal request, thereby reducing invalid TRS transmissions and improving resource utilization.

[0087] In an optional implementation, after preparing to send TRS in response to the identification information and monitoring whether a TRS transmission activation request signal sent by the terminal device is received, sending TRS according to a predetermined tracking mode, the method further includes: after sending a cell handover success response, receiving a third triggering information sent by the serving network device, and responding to the third triggering information to continue preparing to send TRS.

[0088] In request-triggered mode, the target network device responds with identification information to prepare, then receives a third trigger information to continue preparing, and finally sends a TRS when it hears a terminal request. This ensures that the terminal device's request can be responded to in a timely manner, guarantees the accuracy and timeliness of TRS tracking during the handover process, and improves the handover success rate.

[0089] In an optional implementation, the third triggering information is carried in the SN STATUS TRANSFER message.

[0090] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the third triggering information.

[0091] The third aspect is the implementation on the target network device side, which corresponds to the first aspect. The explanations, supplements, and descriptions of the beneficial effects of the first aspect also apply to the third aspect, and will not be repeated here.

[0092] Fourthly, a communication method is provided, which can be executed by a terminal device, or by a component (such as a circuit, chip, or chip system) configured in the terminal device, or by a logic module or software capable of implementing all or part of the functions of the terminal device. In this fourth aspect and its possible implementations, the example of the communication method being executed by a terminal device is provided.

[0093] The method includes: receiving an activation instruction for the Transmission Configuration Indicator (TCI) state of the target network device sent by the serving network device of the terminal device; activating the TCI state; and, upon receiving a cell handover instruction sent by the serving network device or detecting an abnormal signal quality of the serving network device, tracking the tracking reference signal (TRS) issued by the target network device in response to the cell handover request sent by the serving network device based on the TCI state.

[0094] In the above scheme, after activating the TCI state, the terminal device receives the TRS sent by the target network device, and tracks the TRS when it receives a cell handover command or detects abnormal signal quality of the serving network device. Receiving the TRS in advance prepares the signal for subsequent tracking by the terminal device, avoiding synchronization delays caused by receiving the TRS on short notice. Simultaneously, the dual triggering conditions ensure tracking requirements under normal handover scenarios while also addressing situations where the serving network device's signal suddenly deteriorates. This ensures that the terminal device can accurately synchronize via TRS in various scenarios, significantly improving handover success rate and communication continuity, and enhancing system reliability in complex wireless environments.

[0095] In an optional implementation, signal quality anomalies include: signal quality being less than a quality threshold, or the rate of change of signal quality being greater than a rate of change threshold.

[0096] The above scheme clearly defines the judgment criteria for signal quality anomalies, enabling the terminal to accurately trigger the emergency tracking mechanism, avoiding false triggering or missed triggering due to ambiguous judgment criteria, ensuring timely response when emergency tracking TRS is truly needed, further improving the accuracy and reliability of the emergency triggering mode, and ensuring the success rate of handover and communication continuity in scenarios with abnormal signal quality.

[0097] Fifthly, a communication method is provided, which may be executed by a network device, or by a component (such as a circuit, chip, or chip system) configured in the network device, or by a logic module or software capable of implementing all or part of the functions of a terminal device. In this fifth aspect and its possible implementations, the communication method is described as being executed by the serving network device of the terminal device.

[0098] The method includes: sending an activation command for the Transmission Configuration Indicator (TCI) status of the target network device to a terminal device communicating with the serving network device; sending a cell handover request to the target network device; sending a cell handover command to the terminal device upon receiving a successful cell handover response from the target network device; and sending fourth trigger information to the target network device. The fourth trigger information is used to trigger the target network device to continue transmitting TRS.

[0099] In the above scheme, the serving network device sends a TCI status activation command to the terminal device, sends a cell handover request to the target network device, and sends a cell handover command and fourth trigger information after successful handover. This achieves unified coordination and control of the terminal device and the target network device by the serving network device, ensuring that the target network device can send a TRS in advance to support emergency tracking for the terminal device. Simultaneously, the second trigger information ensures continuous transmission of the TRS after handover. This collaborative control mechanism improves the consistency of actions of each node during handover, reduces handover problems caused by information asynchrony, and ensures communication continuity and stability.

[0100] In an optional implementation, the fourth trigger information is carried in the SN STATUS TRANSFER message.

[0101] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the fourth triggering information.

[0102] The fifth aspect is the implementation on the service network device side, which corresponds to the fourth aspect. The explanations, supplements, and descriptions of the beneficial effects of the fourth aspect also apply to the fifth aspect, and will not be repeated here.

[0103] In a sixth aspect, a communication method is provided, which may be executed by a network device, or by a component (such as a circuit, chip, or chip system) configured in the network device, or by a logic module or software capable of implementing all or part of the functions of a terminal device. In this sixth aspect and its possible implementations, the example of the communication method being executed by the target network device to which the terminal device is to be switched is described.

[0104] The method includes: receiving a cell handover request sent by the serving network device of the terminal device; sending a TRS in response to the cell handover request; and, if the handover is successful, continuing to send a TRS in response to a fourth triggering information sent by the serving network device.

[0105] In the above scheme, the target network device sends a TRS in response to the cell handover request, and continues to send TRS after receiving the fourth trigger information following a successful handover. This allows the target network device to provide TRS early in the handover process, meeting the emergency tracking needs of terminal devices when the serving network device's signal is abnormal and avoiding handover failure. Simultaneously, continuous sending after a successful handover ensures stable synchronization of the terminal device in the initial handover phase, reducing the risk of communication interruption after handover. This phased sending strategy of the target network device not only guarantees communication needs in emergency scenarios but also supports stable communication after handover, improving the reliability of the entire communication system.

[0106] In an optional implementation, the fourth trigger information is carried in the SN STATUS TRANSFER message.

[0107] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the fourth triggering information.

[0108] The sixth aspect is the implementation on the target network device side, which corresponds to the fourth aspect. The explanations, supplements, and descriptions of the beneficial effects of the fourth aspect also apply to the sixth aspect, and will not be repeated here.

[0109] In a seventh aspect, a communication method is provided, which may be executed by a terminal device, or by a component (such as a circuit, chip, or chip system) configured in the terminal device, or by a logic module or software capable of implementing all or part of the functions of the terminal device. In this seventh aspect and its possible implementations, the example of the communication method being executed by a terminal device is provided.

[0110] The method includes: receiving an activation instruction for the Transmission Configuration Indicator (TCI) state of a target network device sent by the serving network device of the terminal device; activating the TCI state; receiving a cell handover instruction sent by the serving network device; sending a Tracking Reference Signal (TRS) Transmission Activation Request Signal to the target network device; and tracking the TRS based on the TCI state. Here, the target network device is the network device that the terminal device will hand over to, and the TRS is issued based on the response to the TRS Transmission Activation Request Signal.

[0111] In the above scheme, after activating the TCI state and receiving the cell handover command, the terminal device triggers the reception and tracking TRS by sending a TRS transmission activation request signal. This proactive request mechanism allows the terminal device to accurately trigger TRS transmission based on its own reception readiness, avoiding resource waste caused by the target network device blindly sending TRS. Simultaneously, by sending the request before receiving the tracking TRS, the terminal device ensures it is ready to receive, enabling rapid and accurate synchronization, reducing synchronization latency, improving handover efficiency, and guaranteeing the user's communication experience during handover.

[0112] In an optional implementation, sending a TRS transmission activation request signal to the target network device includes: sending the TRS transmission activation request signal on the physical uplink control channel (PUCCH) resource associated with the target network device.

[0113] In the above scheme, PUCCH, as a channel dedicated to transmitting uplink control information, has the characteristics of low transmission latency and high reliability. By using the PUCCH associated with the target network device to send an activation request signal, it can ensure that the request signal is transmitted to the target network device quickly and reliably, reduce the transmission latency of the request signal, and enable the target network device to respond to the request and send TRS in a timely manner.

[0114] In an eighth aspect, a communication method is provided, which may be executed by a network device, or by a component (such as a circuit, chip, or chip system) configured in the network device, or by a logic module or software capable of implementing all or part of the functions of a terminal device. In this eighth aspect and its possible implementations, the communication method is described as being executed by a serving network device of the terminal device.

[0115] The method includes: sending an activation command for the Transmission Configuration Indicator (TCI) status of the target network device to a terminal device communicating with the serving network device; sending a cell handover request to the target network device; sending a cell handover command to the terminal device upon receiving a successful cell handover response from the target network device; and sending a fifth triggering message to the target network device. The target network device is the network device to which the terminal device will hand over, and the fifth triggering message instructs the target network device to continue preparing to send a Transmission Activation Request (TRS) signal, so that it can send a TRS upon detecting a TRS transmission activation request signal sent by the terminal device.

[0116] In the above scheme, the serving network device sends a TCI status activation command to the terminal device, sends a cell handover request to the target network device, and sends a cell handover command and fifth trigger information after a successful handover. This allows the serving network device to coordinate the readiness status of the target network device in advance, ensuring that the target network device is ready when the terminal device may send a request, avoiding request response delays caused by the target network device not being ready. Simultaneously, the third trigger information further confirms the readiness status, ensuring the smooth operation of the request-based triggering mode and improving resource utilization and handover success rate.

[0117] In an optional implementation, the fifth trigger information is carried in the SN STATUS TRANSFER message.

[0118] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the fifth triggering information.

[0119] The eighth aspect is the implementation of the service network equipment side, which corresponds to the seventh aspect. The explanations, supplements, and descriptions of the beneficial effects of the seventh aspect also apply to the eighth aspect, and will not be repeated here.

[0120] In a ninth aspect, a communication method is provided, which may be executed by a network device, or by a component (such as a circuit, chip, or chip system) configured in the network device, or by a logic module or software capable of implementing all or part of the functions of a terminal device. In the ninth aspect and its possible implementations, the example described is that the communication method is executed by the target network device to which the terminal device is to be switched.

[0121] The method includes: receiving a cell handover request sent by the serving network device of the terminal device; preparing to send a TRS in response to the cell handover request; after sending a successful cell handover response, continuing to prepare to send a TRS in response to the fifth trigger information sent by the serving network device; listening for whether a TRS transmission activation request signal sent by the terminal device is received; and sending a TRS if a TRS transmission activation request signal is received.

[0122] In the above scheme, the target network device prepares to send a TRS (Transaction Responder) based on the response identifier information, continues preparation after receiving the third trigger information, and finally sends the TRS when it detects a terminal request. This multi-stage preparation and request-response mechanism ensures that the target network device is always in a responsive state and will not miss any terminal device requests; at the same time, sending the TRS only after receiving a request enables on-demand allocation of TRS resources and avoids unnecessary resource consumption. This mechanism not only ensures timely response to terminal device requests but also improves network resource utilization, ensuring the accuracy and efficiency of handover in the request-triggered mode.

[0123] In an optional implementation, the fifth trigger information is carried in the SN STATUS TRANSFER message.

[0124] In the above scheme, the existing signaling process is reused and the triggering efficiency is improved by using the SN STATUS TRANSFER message to transmit the fifth triggering information.

[0125] The ninth aspect is the implementation on the target network device side, which corresponds to the seventh aspect. The explanations, supplements, and descriptions of the beneficial effects of the seventh aspect also apply to the ninth aspect, and will not be repeated here.

[0126] In a tenth aspect, embodiments of this application provide a communication device comprising: a module for performing the methods of any one of the first to ninth aspects, such as a transceiver module and a processing module. The transceiver module is used to instruct the transceiver functions of the communication device, and the processing module is used to perform functions of the communication device other than the transceiver functions.

[0127] In an optional implementation, the transceiver module may include a transmitting module and a receiving module. The transmitting module implements the transmitting function of the communication device according to the tenth aspect, and the receiving module implements the receiving function of the communication device according to the tenth aspect.

[0128] Furthermore, the technical effects of the communication device in the tenth aspect can be referenced from the technical effects of any of the implementation methods in the first to ninth aspects, and will not be elaborated here.

[0129] Eleventhly, a communication device is provided, including a processor. The processor is coupled to a memory and can be used to execute instructions or data in the memory to implement the methods in any of the possible implementations of the first to ninth aspects described above.

[0130] Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, to which the processor is coupled.

[0131] In one implementation, the communication interface can be a transceiver, or an input / output interface.

[0132] In another implementation, the communication device is a chip configured in a terminal device. When the communication device is a chip configured in a terminal device, the communication interface can be an input / output interface.

[0133] In a twelfth aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is used to receive signals through the input circuit and to transmit signals through the output circuit, causing the processor to execute a method in any possible implementation of any aspect.

[0134] In specific implementation, the processor can be one or more chips, the input circuit can be input pins, the output circuit can be output pins, and the processing circuit can be transistors, gate circuits, flip-flops, and various logic circuits. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to and transmitted by a transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as both the input circuit and the output circuit at different times. This application does not limit the specific implementation of the processor and various circuits.

[0135] In a thirteenth aspect, a communication device is provided, including a processor and a memory. The processor is used to read instructions stored in the memory and to receive signals via a receiver and transmit signals via a transmitter to execute the method in any possible implementation of any of the preceding aspects.

[0136] Optionally, the processor may be one or more, and the memory may be one or more.

[0137] In a fourteenth aspect, a computer program product is provided, the computer program product comprising: a computer program (also referred to as code or instructions) that, when the computer program is run, causes a computer to perform a method in any possible implementation of any of the above aspects.

[0138] In a fifteenth aspect, a computer-readable storage medium is provided that stores a computer program (also referred to as code or instructions) that, when run on a computer, causes the computer to perform the methods in any possible implementation of any of the preceding aspects.

[0139] In a sixteenth aspect, embodiments of this application provide a chip system including one or more processors for calling and executing instructions stored in memory, causing the methods in any of the above aspects or any possible implementations of the above aspects to be executed. The chip system may be composed of chips or may include chips and other discrete devices.

[0140] The chip system may include input circuits or interfaces for transmitting information or data, and output circuits or interfaces for receiving information or data.

[0141] In a seventeenth aspect, a communication system is provided, including the aforementioned terminal device, serving network device, and target network device. Optionally, the communication system may further include other devices that communicate with the terminal device and / or network device.

[0142] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, embodiments of this application are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0143] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings.

[0144] Figure 1 A schematic diagram of a communication system provided in an embodiment of this application;

[0145] Figure 2 A schematic diagram illustrating terminal behavior during two cell handover scenarios provided by existing technologies;

[0146] Figure 3 An interaction diagram of the first communication method provided in the embodiments of this application;

[0147] Figure 4 An interaction diagram for the second communication method provided in the embodiments of this application;

[0148] Figure 5 An interaction diagram for the third communication method provided in the embodiments of this application;

[0149] Figure 6 An interaction diagram for the fourth communication method provided in the embodiments of this application;

[0150] Figure 7 An interaction diagram for the fifth communication method provided in the embodiments of this application;

[0151] Figure 8 An interaction diagram for the sixth communication method provided in the embodiments of this application;

[0152] Figure 9 An interaction diagram for the seventh communication method provided in the embodiments of this application;

[0153] Figure 10 An interaction diagram for the eighth communication method provided in the embodiments of this application;

[0154] Figure 11 A schematic block diagram of a communication device provided in the embodiments of this application;

[0155] Figure 12 Another schematic block diagram of the communication device provided in the embodiments of this application. Detailed Implementation

[0156] The technical solutions provided in this application can be applied to various communication systems, such as: Global System for Mobile Communications (GSM) systems, General Packet Radio Service (GPRS), Wireless Local Area Network (WLAN), Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, sidelink communication systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, non-terrestrial network (NTN) communication systems, 5th generation (5G) mobile communication systems, or new radio access technology (NR). Among these, 5G mobile communication systems can include non-standalone (NSA) and / or standalone (SA) networking. The technical solutions provided in this application can also be applied to future communication systems. This application does not limit the scope of these applications.

[0157] Please refer to Figure 1 , Figure 1 This is a schematic diagram of a communication system provided in an embodiment of this application. The communication system 100 may include two network devices, such as... Figure 1 The shown network devices are a serving network device 110 and a target network device 130. The serving network device 110 is the network device currently providing services to the terminal device 120, while the target network device 130 is the network device to which the terminal device 120 will switch. The communication system 100 may also include terminal devices, such as… Figure 1 The terminal device 120 shown. The serving network device 110 and the target network device 130 can communicate with the terminal device 120 via a wireless link, and the serving network device 110 and the target network device 130 can communicate via the Xn interface.

[0158] Figure 1Two network devices 110 and one terminal device 120 are illustrated exemplarily. Optionally, the communication system 100 may include multiple network devices and / or multiple terminal devices; for example, the communication system may include multiple candidate network devices, and the target network device 130 is one of the multiple candidate network devices.

[0159] In the cell handover method provided in the embodiments of this application, Figure 1 The serving network device 110 shown can be used to issue a cell handover command to the terminal device 120, while the target network device 130 can be used to send a tracking reference signal, so that the terminal device 120 can start tracking the tracking reference signal after receiving the cell handover command, thereby completing the cell handover process from the serving network device 110 to the target network device 130.

[0160] The network equipment in this application can be network-side equipment such as access network equipment and core network equipment. Access network equipment is sometimes also called access node. Access network equipment has wireless transceiver capabilities and is used to communicate with terminals. Access network equipment includes, but is not limited to, base stations, evolved NodeBs (eNodeBs), transmission reception points (TRPs) in the above-mentioned communication systems, next-generation NodeBs (gNBs) in 5G mobile communication systems, access network equipment or modules of access network equipment in open RAN (ORAN) systems, satellites in NTN communication systems, base stations in future mobile communication systems, or access nodes in WiFi systems. Access network equipment can also be modules or units capable of implementing some functions of a base station. Access network equipment can be macro base stations, micro base stations, or indoor stations, relay nodes or donor nodes, or wireless controllers in cloud radioaccess network (CRAN) scenarios. Optionally, access network equipment can also be servers, wearable devices, or vehicle-mounted equipment, etc. Multiple access network equipment in a communication system can be base stations of the same type or different types. Base stations can communicate with terminals directly, or they can communicate with terminals through relay stations. Terminals can communicate with multiple base stations using different access technologies. The embodiments of this application do not limit the specific technologies or device forms used in the access network equipment. In this application, the access network equipment is referred to as a network device.

[0161] In this application, the means for implementing the functions of a network device can be a network device itself, or a means capable of supporting the network device in implementing those functions, such as a processor, circuit, chip, or chip system. This means can be installed in or connected to the network device. In the technical solutions provided in this application, the example of a network device being used to implement the functions of a network device is used to describe the technical solutions provided in this application.

[0162] The terminal device in this application can be a wireless terminal device capable of receiving network device scheduling and instruction information. The wireless terminal device can be a device providing voice and / or data connectivity to a user, a handheld device with wireless connectivity, or other processing devices connected to a wireless modem. For example, the terminal device can communicate with one or more core networks or the Internet via a radio access network (RAN). The terminal device can also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), machine-type communication (MTC), Internet of Things (IoT), ultra-reliable low-latency communication (URLLC), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, or satellite communication, etc. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, wearable device, vehicle, aircraft (such as drone, helicopter, airplane), hot air balloon, ship, robot, robotic arm, or smart home device, etc. The embodiments of this application do not limit the form of the terminal device.

[0163] In this application, the apparatus for implementing the functions of a terminal device can be the terminal device itself, or any apparatus capable of supporting the terminal device in implementing those functions, such as a processor, circuit, chip, or chip system. This apparatus can be installed in or connected to the terminal device. In the technical solutions provided in this application, the example of a terminal device being used to implement the functions of a terminal device is used to describe the technical solutions provided in this application.

[0164] Access network equipment and / or terminal equipment can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites. This application does not limit the application scenarios of the access network equipment and terminal equipment. They can be deployed in the same or different scenarios; for example, both can be deployed on land simultaneously; or the access network equipment can be deployed on land while the terminal equipment is deployed on water, etc., and so on.

[0165] In practical applications, multiple network devices can collaborate to assist terminals in achieving wireless access, with different network devices each implementing a portion of the base station's functions. For example, network devices can be central units (CUs), distributed units (DUs), CUs (control planes, CPs), CUs (user planes, UPs), or radio units (RUs), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0166] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (Open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. CU (or CU-CP and CU-UP), DU, and RU can implement different protocol layer functions.

[0167] In existing technologies, to address the problem that candidate cells are unaware of whether the TRS transmitted to terminal devices connected to them is being monitored by terminal devices connected to neighboring cells, thus preventing candidate cells from pausing TRS transmission, Rel-18 introduces the following two terminal behaviors: Figure 2The examples show terminal behavior 1 and terminal behavior 2. Please refer to... Figure 2 , Figure 2 This diagram illustrates the terminal behavior during two cell handover scenarios provided by existing technologies.

[0168] In terminal behavior 1, the serving cell configures a TCI state containing candidate cell TRS information for the terminal device. To ensure the terminal device can perform early tracking at any time, the candidate cell begins to continuously and unconditionally transmit TRS signals immediately after receiving this configuration. Upon receiving this configuration, the terminal device can immediately track the candidate cell's TRS even before a cell handover command is issued, thus making full preparations for handover. While this behavior ensures a seamless handover experience on the terminal side, it causes significant resource waste on the network side. The candidate cell needs to continuously broadcast the TRS, but this broadcast is ineffective most of the time because the potential handover does not actually occur most of the time.

[0169] In terminal behavior 2, the serving cell does not configure the candidate cell's TRS for the terminal device before issuing the handover command. The terminal device relies on the more basic SSB, which is always broadcast on the network, for initial tracking. Only after the formal handover process is completed, i.e., after the terminal device receives the cell handover command sent by the serving cell, does the terminal device activate the new TCI state in the new cell and begin using the TRS for precise tracking. Although this behavior solves the problem of resource waste by not sending the TRS in advance, it sacrifices handover performance. During the critical stages of handover decision and execution, the terminal device cannot use the TRS for precise tracking, which may lead to slower synchronization speed, increased handover latency, and even handover failure in complex signal environments, thereby reducing user experience and network reliability.

[0170] In summary, existing technologies cannot simultaneously meet the two key requirements of high switching performance and high resource efficiency.

[0171] In view of this, this application provides a communication method in which a terminal device can activate the TCI state before receiving a cell handover instruction from the serving network device. Thus, when cell handover is required, the terminal device can track the TRS sent by the target network device based on the TCI state, according to a pre-determined tracking mode (different tracking modes have different triggering conditions). This communication method decouples the TRS configuration from its physical transmission. By introducing explicit triggering conditions, the terminal device does not immediately track the TRS after the TCI state is activated, as in existing solutions, but only tracks the TRS when the triggering conditions are met. Simultaneously, the serving network device informs the target network device when to send the TRS based on different configured triggering conditions, ensuring that the TRS is transmitted only when absolutely necessary, but can be readily utilized by the terminal device when needed.

[0172] To facilitate understanding of the embodiments of this application, the terminology used in this application will be briefly explained first. Optionally, the explanation of some terms may also refer to the explanations in the 3rd Generation Partnership Project (3GPP) standard protocol.

[0173] The TCI state is a configuration state in wireless communication used to indicate quasi-co-location relationships. It informs terminal devices of key configuration information on how to receive specific reference signals (e.g., TRS), thereby assisting the UE in beam management and downlink channel estimation. In the embodiments of this application, the TCI state is used to configure the TRS resources of candidate network devices (e.g., frequency location, time period, beam direction, resource block allocation, etc.) to prepare the UE for signal synchronization in advance.

[0174] The TCI state activation command is a signaling instruction issued by the serving network device to trigger a terminal device to enable a configured TCI state. In one implementation, the TCI state activation command can be sent via a medium access control element (MAC CE). TCI state activation refers to the terminal device's preparatory action to track the target network device's TRS (Tracking Service Responsibility Request), and TRS availability means that the target network device has begun sending TRS.

[0175] A cell handover instruction is an instruction sent by a serving network device to a terminal device to instruct the terminal device to hand over from the current serving cell to a target cell. In the embodiments of this application, the cell handover instruction is used to instruct the terminal device to hand over from the serving network device to the target network device.

[0176] TRS is a dedicated reference signal used for downlink time and frequency tracking. Compared to the always-broadcast SSB, TRS has higher accuracy; therefore, using TRS for synchronization can significantly improve the performance and speed of cell handover.

[0177] The preset tracking mode is a TRS tracking logic framework designed in this application embodiment to resolve the contradiction between high handover performance and high resource efficiency. It is a set of rules that guides the terminal device when to track TRS and the target network device when to send TRS. The preset tracking mode may include multiple tracking modes. Therefore, in this application embodiment, the preset tracking mode is a tracking mode determined from multiple preset tracking modes. The target network device can send TRS according to the preset tracking mode, and the terminal device can track the TRS according to the preset tracking mode.

[0178] Tracking indication information (TRS) is signaling content sent by the serving network device to the terminal device to transmit information related to the tracking mode. Its core function is to inform the terminal device of the tracking mode determined and specified by the serving network device, enabling the terminal device to send a TRS according to that tracking mode. Its specific value or code uniquely identifies the tracking mode specified by the serving network device. For example, its value can be 00, 01, or 10, used to identify different tracking modes; alternatively, its code can represent the name corresponding to different tracking modes.

[0179] A cell handover request is a signaling message sent by a serving network device to a target network device via the Xn interface. It initiates the cell handover process and requests the target network device to allocate the necessary resources (e.g., TRS resources, service data bearer resources) for the terminal device. As one implementation, the cell handover request can be carried within an XnAP message, specifically a HANDOVER REQUEST message.

[0180] A successful cell handover response is an acknowledgment message sent by the target network device to the serving network device via the Xn interface after receiving a cell handover request, if the target network device agrees and is ready to accept the terminal device. This message informs the serving network device that the configuration of handover resources for the terminal device has been completed. As one implementation, the cell handover request can be carried in an XnAP message, specifically a HANDOVER REQUEST ACKNOWLEDGE message.

[0181] Identification information is an identifier used to uniquely identify the tracking mode specified by the serving network device. Unlike tracking indication information, which is sent by the serving network device to the terminal device so that the terminal device can track the TRS according to the tracking mode, identification information is sent by the serving network device to the target network device so that the target network device can send the TRS according to the tracking mode. It is understood that the specific value or code of the identification information can be the same as or different from the tracking indication information, as long as the tracking indication information and the identification information correspond to each other, ensuring that the tracking mode indicated to the terminal device and the tracking mode indicated to the target network device are the same.

[0182] A Transmission Activation Request (TRS) signal is an uplink control signal sent by a terminal device to a target network device to actively request the target network device to send a TRS. In one implementation, the terminal device can send this TRS transmission activation request signal on the PUCCH resource associated with the target network device through the Physical Uplink Control Channel (PUCCH) resource list configured by the serving network device.

[0183] The first, second, third, fourth, and fifth trigger messages (collectively referred to as trigger messages) are all signaling messages sent by the serving network device to the target network device through the Xn interface, used to instruct the target network device when to send TRS under different tracking modes.

[0184] It should be understood that the technical terms used in this application are for illustrative purposes only and not as limiting. For example, as technology evolves, technical terms may also change, and other technical terms that have the same technical meaning should also apply to this application.

[0185] The solution provided in this application will be described in detail below with reference to the corresponding flowcharts. It is understood that the illustrative flowcharts provided in this application primarily use different devices (e.g., terminal devices, network devices) as examples of the execution subjects of this interactive illustration to illustrate the method, but this application does not limit the execution subjects of the interactive illustrations. For example, the devices (e.g., terminal devices, network devices) in the illustrative flowcharts can also be chips, chip systems, or processors that support the implementation of this method on the device, or logic modules or software that can implement all or part of the functions of the device.

[0186] As a general statement, the message or signaling interactions involved in the interaction process of the embodiments of this application can adopt messages or signaling in existing standards or newly introduced messages or signaling. The embodiments of this application do not make specific limitations on this.

[0187] Please refer to Figure 3 , Figure 3 This is an interaction diagram illustrating the first communication method provided in an embodiment of this application. It can be understood that... Figure 3 The terminal device in the middle can be Figure 1 The term "terminal device" can also refer to the components within a terminal device (such as a processor, chip, or chip system). Serving network equipment and target network equipment can be... Figure 1 The terms "service network equipment" and "target network equipment" can also refer to devices within the corresponding network equipment (such as processors, chips, or chip systems). For example... Figure 3 As shown, the method includes the following steps:

[0188] S301: The serving network device sends an activation instruction for the TCI status of the target network device to the terminal device, and the terminal device receives the activation instruction for the TCI status.

[0189] In this scenario, the terminal device receives the activation command earlier than the serving network device sends the cell handover command, and the earliest transmission time of the TRS is later than the transmission time of the activation command. This allows the terminal device to prepare for TRS tracking before receiving the cell handover command, overcoming the drawback of terminal behavior 2 where accurate TRS tracking is impossible before handover, thus sacrificing handover performance. By configuring TRS tracking in advance and activating it at critical moments, the terminal device can quickly and smoothly complete synchronization, avoiding the risk of increased handover latency or even handover failure, and ensuring the smoothness and success rate of the handover.

[0190] For one possible implementation, please refer to Figure 4 Before sending the TCI status activation command to the terminal device (i.e., before S301), the serving network device can first perform the following:

[0191] S201: The serving network device negotiates TRS resources with the candidate network device through the Xn interface.

[0192] S203: The serving network device configures the TCI status of the candidate network devices to the terminal device. The TCI status is used to transmit the negotiated TRS resources to the terminal device. There can be multiple candidate network devices, and the target network device is one of the candidate network devices.

[0193] One possible implementation is that the serving network device can configure the aforementioned TCI state to the terminal device via an RRC reconfiguration message. Specifically, the serving network device can send an RRC reconfiguration message to the terminal device, which carries the TCI state of the candidate network device. After receiving the RRC reconfiguration message, the terminal device can parse it to obtain the TCI state of the candidate network device and complete the configuration of the TCI state of the target candidate network device.

[0194] The terminal device can continuously monitor the SSB signals of surrounding cells and report the measured neighbor cell signal strength (e.g., Reference Signal Receiving Power (RSRP), Reference Signal Receiving Quality (RSRQ)) to the serving network device. The serving network device analyzes the report and initially screens out neighbor cells whose signal quality meets the potential handover requirements as candidate network devices.

[0195] In one implementation, if the number of candidate network devices determined by the serving network device is one, then the candidate serving network device can only determine that candidate network device as the target network device; in this case, the serving network device can only configure the TCI status of the target network device to the terminal device.

[0196] As another implementation, if the number of candidate network devices determined by the serving network device is greater than one, the serving network device then needs to select one network device as the target network device from the multiple candidate network devices. In this case, the serving network device can configure the TCI status of multiple candidate network devices to the terminal device. Specifically, the serving network device can configure the TCI status of multiple candidate network devices separately through multiple messages, for example, one message per candidate network device; or, the serving network device can configure the TCI status of multiple candidate network devices simultaneously through a single message.

[0197] One possible implementation is that the RRC reconfiguration message may include TCI status configuration information, which is used to configure the TCI status of the target network device.

[0198] One possible implementation is that, after configuring the TCI status of candidate network devices to the terminal device, the serving network device can select one network device as the target network device from one or more candidate network devices. For details, please refer to... Figure 4 The communication method provided in this application embodiment may further include:

[0199] S204: The service network device receives the SSB measurement report reported by the terminal device.

[0200] S205: The serving network device analyzes the SSB measurement report and selects the candidate network device that best meets the handover requirements as the target network device.

[0201] The specific implementation method for selecting the target network device that best meets the handover requirements can be found in existing technologies and will not be elaborated here.

[0202] Please continue to refer to this. Figure 3 As shown, after the target network device is identified, the serving network device executes S301, and also executes S302 before, simultaneously with, or after executing S301.

[0203] S302: The serving network device sends a cell handover request and a pre-determined tracking mode identification information to the target network device, and the target network device receives the cell handover request and the pre-determined tracking mode identification information.

[0204] The predetermined tracking mode is one selected from multiple preset tracking modes. This means that these preset tracking modes can be pre-defined by the protocol, i.e., the predetermined tracking mode can be selected from a pre-defined range. For the target network device, at least two preset tracking modes correspond to different TRS transmission timings. For example, the TRS transmission time corresponding to a preset tracking mode can be after receiving the identification information (e.g., ...). Figure 7 The implementation method shown); or, the transmission time of the TRS corresponding to the preset tracking mode can be after receiving the trigger information (e.g. Figure 6 The implementation method shown); or, the transmission time of the TRS corresponding to the preset tracking mode can be after receiving the TRS transmission activation request signal (e.g. Figure 8 (The implementation method shown is shown). In this way, the serious resource waste caused by the target network device needing to continuously broadcast TRS in terminal behavior 1 is avoided. Through conditional activation, the target network device only sends TRS when it receives an explicit instruction or meets specific conditions, thereby avoiding invalid signal broadcasting and significantly improving resource utilization.

[0205] For example, preset tracking modes may include onCSC (cell handover command trigger) mode, emergency trigger mode, and onDemandTrigger mode.

[0206] In the cell handover command-triggered mode, the terminal device does not immediately track the TRS after activating the TCI state. Instead, it prepares to receive the TRS under that TCI state until it receives a cell handover command and the TRS becomes available. Then, it immediately tracks the target network device's TRS. The target network device sends its own TRS after receiving the corresponding trigger information. This tracking mode is a basic and universal conditional activation mode. Compared with existing TRS tracking mechanisms, it can save network resources while maintaining handover performance. The specific implementation process of the cell handover command-triggered mode will be discussed later. Figure 6 The implementation method shown will be described in detail.

[0207] In emergency-triggered mode, to prevent the serving network device from failing to send a cell handover command or the terminal device from failing to receive a cell handover command, thus preventing the terminal device from tracking the TRS normally, the terminal device tracks the TRS after receiving the cell handover command or detecting an abnormal signal quality of the serving network device. The target network device sends a TRS after receiving the tracking instruction information. The specific implementation process based on emergency-triggered mode will be discussed later. Figure 7 The implementation method shown will be described in detail.

[0208] If the communication between the terminal device and the serving network device is normal, the terminal device can receive the cell handover command sent by the serving network device and track the TRS. If the communication between the terminal device and the serving network device is abnormal, the terminal device will not be able to receive the cell handover command sent by the serving network device normally or will receive it with a delay. This may cause the terminal device to be unable to track the TRS in time when cell handover is required. Therefore, the terminal device can monitor the signal quality of the serving network device and track the TRS after detecting an abnormality in the signal quality of the serving network device.

[0209] This tracking mode is an emergency protection mechanism configured based on the cell handover command triggering mode. It can be used to solve the situation where a terminal device may fail to receive the cell handover command when it suddenly loses contact with the serving network device (e.g., entering an elevator, turning a street corner, etc.), thus affecting the subsequent handover performance.

[0210] One possible way to identify signal quality anomalies is when the signal quality falls below a quality threshold. This quality threshold is configured on the serving network device side, and its value can vary depending on the actual situation. For example, the RSRP threshold can be dynamically adjusted by the serving network device based on the mobility status of the uploaded terminal device, categorized into high-speed, medium-speed, and low-speed states. A higher RSRP threshold is configured for high-speed scenarios, and a lower RSRP threshold is configured for low-speed scenarios. In this implementation, a sudden and drastic deterioration in the signal quality of the serving network device, falling below the aforementioned quality threshold, can also be considered a signal quality anomaly.

[0211] One possible way to identify signal quality anomalies is when the rate of change in signal quality exceeds a rate of change threshold. For example, within a time window defined by the time-window, the RSRP of the serving network device drops beyond the rate of change threshold rsrp-Drop. In this implementation, a sudden and drastic deterioration in the signal quality of the serving network device, exceeding the aforementioned rate of change threshold, can also be considered a signal quality anomaly.

[0212] In the request-triggered mode, after receiving a cell handover command, the terminal device sends a TRS transmission activation request signal to the target network device and tracks the TRS. The target network device, upon receiving the TRS transmission activation request signal, sends its own TRS. This tracking mode is an optimization mechanism based on the cell handover command-triggered mode, which can solve the problem that a mismatch between the network-side Xn interface signaling delay and the air interface signaling delay might cause the terminal device to start tracking before the TRS arrives. In this tracking mode, the target network device only consumes resources to send the TRS when it confirms that the terminal device is ready to receive; if the terminal device fails to respond after receiving the cell handover command for some reason (e.g., a system crash), the target network device will not send a TRS in vain. The specific implementation process based on the request-triggered mode will be discussed later. Figure 8 The implementation method shown will be described in detail.

[0213] It should be noted that the above-mentioned preset tracking modes are only three examples provided in the embodiments of this application. In actual applications, preset tracking modes also include other tracking modes. This application does not specifically limit these modes, as long as they can meet the requirements of a certain business scenario or network environment and balance network resources and switching performance. For example, in the case of the business demand triggering mode, when the business data arrives, the serving network device can send a corresponding triggering signaling to the terminal device so that the terminal device tracks the TRS; or, in the case of the location triggering mode, the terminal device starts tracking the TRS when it enters the triggering area of ​​the target network device, etc.

[0214] The design of the aforementioned multiple preset tracking modes is a tracking mechanism that allows for flexible selection based on actual conditions, enhancing adaptability to different wireless scenarios and service requirements. Among them, the cell handover command-triggered mode serves as the basic mode, ensuring a balance between handover performance and resource efficiency; the emergency trigger mode acts as an emergency backup mechanism, improving network robustness in the event of sudden link failures; and the request-based trigger mode serves as an optimization mechanism, achieving fine-grained on-demand control of TRS resources through a closed-loop request approach. By introducing both the emergency trigger mode and the request-based trigger mode, the communication method provided in this application embodiment can not only handle standard handover procedures but also cope with scenarios involving sudden link failures and extremely high service quality requirements, demonstrating high adaptability and robustness.

[0215] Optionally, the specific representation of the identification information can be a number, symbol, letter, or other identifier. When the identification information is a binary number, the correspondence between the identification information and the above three preset tracking modes is as follows: the specific value of the identification information is 00, which corresponds to the cell handover command trigger mode; the specific value of the identification information is 01, which corresponds to the emergency trigger mode; and the specific value of the identification information is 10, which corresponds to the request trigger mode.

[0216] One possible implementation is that the cell handover request and identification information can be sent to the network device via the same message or two separate messages. Optionally, if sent as two separate messages, the two messages can be sent simultaneously.

[0217] For example, cell handover requests and identification information can be carried in HANDOVER REQUEST messages. By reusing existing messaging tracking mode information, signaling complexity and latency are reduced, ensuring that the target network device is informed of the tracking mode in a timely manner, which facilitates its preparation for TRS transmission.

[0218] One possible approach is that the HANDOVER REQUEST message may include an extended information element (IE). This extended IE field contains the aforementioned identification information, used to inform the target network device to prepare for sending a TRS. For example, the extended IE field can be named Conditional Trace Reference Signal Configuration (ConditionalTRSConfig). Taking a specific value of 00 for this identification information, the configuration structure of the extended IE in the XnAP message is as follows:

[0219]

[0220] As an alternative implementation, the cell handover request and identification message can also be sent to the network device as two separate messages. For example, the cell handover request can be carried in a HANDOVER REQUEST message, and the second identification message can be carried in a new message.

[0221] One possible implementation is that the pre-determined tracking mode can be a tracking mode determined by the serving network device or terminal device from a variety of preset tracking mechanisms.

[0222] As one implementation method, the pre-determined tracking mode is the tracking mode selected and specified by the serving network device from a variety of preset tracking mechanisms. As the core control node on the network side, the serving network device can obtain more comprehensive global information. Therefore, having the serving network device select and specify the tracking mode from a variety of preset tracking mechanisms ensures that the selected mode is highly adapted to the current communication scenario, thereby more accurately balancing switching performance and resource efficiency.

[0223] For details, please refer to Figure 4 The communication method provided in this application embodiment may further include:

[0224] S202: The serving network device determines a predetermined tracking mode from a variety of preset tracking modes based on one or more of the terminal device's wireless channel and link quality information, terminal information, service type, network topology information, and historical data.

[0225] Among them, wireless channel and link quality information refers to the transmission characteristics and link communication quality related data of the wireless channel between the terminal device and the serving network device and the target network device. It can be obtained by analyzing the measurement reports reported by the terminal device, such as the signal quality of the serving network device, the fading of the wireless channel, the delay spread, the Doppler shift, RSRP, RSRQ, etc. reported by the terminal device.

[0226] Terminal information refers to data acquired by the service network equipment that is related to the terminal equipment's own capabilities and operating status, such as: the terminal equipment's mobility state estimation, the terminal equipment's ability to support this tracking mode, and the terminal equipment's operating status.

[0227] Service type refers to the type of communication service currently carried by the terminal device, such as: non-real-time services (e.g., web browsing, file download, etc.), real-time services (e.g., VoNR (5G New Voice) calls, etc.), and services that are extremely sensitive to interruptions (e.g., ultra-reliable and low-latency communications (uRLLC) applications such as remote surgery).

[0228] Network topology information refers to data obtained by service network devices that relates to the distribution, coverage, and interference of base stations in the communication network, such as the relationship between base station distribution and coverage, network resource load, and characteristics of interference scenarios.

[0229] Historical data refers to statistical data stored by service network equipment that relates to communication performance in a specific area and historical communication records of terminals, such as historical handover success rate, probability of radio link failure (RLF), and historical communication data.

[0230] When the preset tracking mode includes a cell handover command-triggered mode, the serving network device can decide whether to configure this tracking mode based on the following criteria: 1. It can be based on the measurement reports reported by the terminal device. For example, if the reported neighboring cell signal strength (RSRP or RSRQ) smoothly exceeds that of the serving network device without drastic fluctuations, the tracking mode can be considered. 2. It can be based on the mobility status assessment of the terminal device. For example, if the terminal device is in a stable high-speed or medium-speed movement state with a regular trajectory, the tracking mode can be considered. 3. It can be based on the service type. For example, for non-real-time services (such as web browsing and file download), the tracking mode can be considered. 4. It can be based on historical data. For example, if the historical handover success rate in the area is high and the probability of wireless link failure is low, the tracking mode can be considered. In actual decision-making, one or more of the above criteria can be used.

[0231] When the preset tracking mode includes an emergency trigger mode, the serving network device can decide whether to configure this tracking mode based on the following criteria: 1. It can be based on radio link quality alarms, for example, when the signal quality of the serving cell reported by the terminal device is below a danger threshold, or the signal drop rate is too fast in a short period of time, the tracking mode can be considered; 2. It can be based on historical data analysis, for example, when the current area is a high-incidence area of ​​radio link failure, or when this terminal device has had multiple RLF records in the past, the tracking mode can be considered; 3. It can be based on the service type, for example, when the terminal device is performing a service that is extremely sensitive to interruption, such as VoNR (5G New Voice) calls or uRLLC applications such as remote surgery, the priority of avoiding dropped calls is higher than other factors, so the tracking mode can be considered. In the actual decision-making process, one or more of the above criteria can be used as a basis for decision-making.

[0232] When the preset tracking mode includes a request-triggered mode, the serving network device can decide whether to configure this tracking mode based on the following criteria: 1. It can be based on network topology and interference conditions. For example, when the terminal device is in an overlapping coverage area of ​​multiple cells, activating TRS may cause interference to neighboring cells. Therefore, it is necessary to activate TRS on demand and deactivate it after use; thus, configuring this tracking mode can be considered. 2. It can be based on the capabilities of the terminal device. For example, when the terminal device reports that it supports this on-demand request closed-loop capability, configuring this tracking mode can be considered. In actual decision-making, one or more of the above criteria can be used.

[0233] It should be noted that S201 and S202 can be executed in parallel or sequentially.

[0234] Accordingly, if the predetermined tracking pattern is determined by the service network device, please refer to... Figure 4 Before receiving the activation instruction (i.e., S301) from the serving network device of the terminal device regarding the transmission configuration indication (TCI) status of the target network device, the communication method provided in this application embodiment may further include:

[0235] S203: The serving network device sends tracking indication information to the terminal device, and the corresponding terminal device receives the tracking indication information sent by the serving network device.

[0236] One possible implementation is that the tracking indication information is used to indicate a pre-determined tracking pattern.

[0237] exist Figure 4 In the example shown, the tracing indication information can be carried in the message configuring the TCI status of the target network device, so the two correspond to the same execution action S203. However, in other examples, the tracing indication information may be a different message from the message configuring the TCI status. The message sending the tracing indication information can be sent simultaneously with the message configuring the TCI status, or it can be sent sequentially.

[0238] As one implementation method, tracking indication information can be carried in RRC signaling. By utilizing existing RRC signaling to transmit tracking indication information, there is no need to establish a new signaling transmission channel, which reduces implementation complexity, improves the efficiency and reliability of signaling transmission, and maintains compatibility with existing protocols.

[0239] For example, tracing indication information can be carried in RRC reconfiguration messages. By utilizing existing RRC reconfiguration messages to deliver tracing indication information, there is no need to establish new signaling transmission channels, which reduces implementation complexity, improves the efficiency and reliability of signaling transmission, and maintains compatibility with existing protocols.

[0240] The RRC reconfiguration message may include TCI status configuration information, which includes quasi-co-location information (QCL-Info). The QCL-Info carries tracking indication information.

[0241] One possible approach is that the specific representation of the tracking indication information can be a number, a symbol, a letter, or other identifier.

[0242] For example, a binary value of 00 for the tracking indication information corresponds to the cell handover command trigger mode, a binary value of 01 for the tracking indication information corresponds to the emergency trigger mode, and a binary value of 10 for the tracking indication information corresponds to the request trigger mode.

[0243] For example, the tracking indication information can be the identifier "onCSC", corresponding to the cell handover command triggering mode; the tracking indication information can be the identifier "emergencyTrigger", corresponding to the emergency triggering mode; and the tracking indication information can be the identifier "onDemandTrigger", corresponding to the request-based triggering mode.

[0244] For example, the tracking indication information can be the identifier "onCSC", corresponding to the cell handover command triggering mode; the tracking indication information can be the identifier "onCSC" and "emergencyTrigger", corresponding to the emergency triggering mode; and the tracking indication information can be the identifier "onCSC" and "onDemandTrigger", corresponding to the request-based triggering mode.

[0245] One possible approach is to add an optional tracking indication to QCL-Info, placing this information in a field named Tracking Reference Signal Trigger Condition (TRS-ActivationTriggerCondition). Taking the tracking indication as represented by onCSC, emergencyTrigger, and onDemandTrigger as an example, the configuration structure of the TRS-ActivationTriggerCondition field in QCL-Info is as follows:

[0246] RSRP-Range is an existing standard type, RSRP-Range ::= INTEGER (0..127).

[0247] It should be noted that, for the purpose of illustration, the code lists the tracking indication information corresponding to the three tracking modes. In actual use, the tracking indication information corresponding to the predetermined tracking mode can be placed only in the TRS-ActivationTriggerCondition field.

[0248] Therefore, this application embodiment introduces a TCI state configuration with conditional activation triggering by adding an optional TRS-ActivationTriggerCondition field to the QCL-Info of the RRC reconfiguration message. This field allows the network to pre-configure the TRS resources of the target network device for the terminal device, but the terminal device will not immediately track it. Instead, it will only start tracking after the specific conditions set by this field are met (such as receiving a cell handover instruction). This decouples the configuration distribution from the physical transmission, solves the contradiction between handover performance and resource efficiency in the prior art, and ensures that TRS is transmitted only when absolutely necessary, but can be used by the terminal device immediately when needed.

[0249] One possible approach is that after receiving an RRC reconfiguration message from the serving network device, the terminal device can parse whether the TRS-ActivationTriggerCondition field is configured to determine the specific action to take upon receiving a TCI state activation. If this field is not configured, the terminal device can use existing technology for cell handover. If the field is configured, the terminal device will not immediately track the target network device's TRS after TCI state activation. Instead, it will prepare to receive signals and then conditionally activate and track the target network device's TRS according to the tracking mode configured in the TRS-ActivationTriggerCondition field.

[0250] In other words, when the pre-determined tracking mode is selected by the serving network device from multiple preset tracking modes, the serving network device can first select the pre-determined tracking mode from the multiple preset tracking modes, and then send tracking instruction information to the terminal device, as well as a cell handover request and the identification information of the pre-determined tracking mode to the target network device. Therefore, the terminal device can understand the subsequent tracking logic before receiving the TCI state activation instruction and make tracking preparations in advance. This advance notification method avoids the delay caused by the terminal device temporarily determining the tracking mode after activating the TCI state, ensuring that the terminal device can quickly and accurately track the TRS when the triggering conditions are met, further ensuring the timeliness and smoothness of handover, reducing handover latency, and improving the user communication experience.

[0251] The preceding section described the process by which the serving network device determines the tracking mode from multiple preset tracking modes and instructs the terminal device. The following section describes the process by which the terminal device determines a predetermined tracking mode from multiple preset tracking modes and informs the serving network device. As the direct user of the communication service, the terminal device has the most intuitive and timely perception of its own real-time status. Therefore, allowing the terminal device to autonomously determine the tracking mode from multiple preset modes allows it to flexibly adjust according to its actual situation. This not only reduces the decision-making burden and signaling interaction overhead of the serving network device but also ensures that the tracking mode selection better suits the terminal's real-time needs.

[0252] For details, please refer to Figure 5 , Figure 5 The interaction diagram of the third communication method provided in this application embodiment shows that, before receiving the activation instruction of the transmission configuration indication (TCI) state of the target network device sent by the serving network device of the terminal device (i.e., S301), the communication method provided in this application embodiment may further include the following steps:

[0253] S401: The terminal device determines a predetermined tracking mode from a variety of preset tracking modes based on one or more of the following: wireless channel and link quality information, terminal information, service type, network topology information, and historical data.

[0254] The specific implementation of this step is similar to that of S202, and will not be repeated here. Specifically, the terminal device can obtain wireless channel and link quality information through active measurement and signal analysis; the terminal device can locally store or collect terminal information in real time; the terminal device can obtain service types through interaction with network signaling via the terminal service module; the terminal device can obtain network topology information through network signaling broadcasting or dedicated signaling interaction; and the terminal device can locally cache historical records.

[0255] S402: The terminal device sends tracking indication information to the serving network device, and the serving network device receives the tracking indication information sent by the terminal device.

[0256] After determining the tracking mode, the terminal device needs to inform the serving network device of the determined tracking mode so that the serving network device can send identification information to the target network device based on the determined tracking mode. The terminal device can inform the serving network device of its tracking mode by sending corresponding signaling.

[0257] Please continue to refer to this. Figures 3-5 The communication method further includes, either simultaneously with, before, or after the execution of S302:

[0258] S303: Terminal device activates TCI status.

[0259] Upon receiving the TCI state activation command, the terminal device immediately performs the TCI state activation operation, completing the parameter configuration related to TRS reception of the target network device, such as determining the resource location and quasi-co-location relationship of the TRS. In this embodiment, the terminal device does not immediately track the TRS after activating the TCI state.

[0260] S304: Upon receiving a successful cell handover response from the target network device, the serving network device sends a cell handover command to the terminal device.

[0261] After receiving a cell handover request from the serving network device, the target network device can parse the information in the request to allocate the necessary resources for the handover to the terminal device. If the resource allocation is successful and all preparations are completed, the target network device can send a cell handover success response to the serving network device. Upon receiving this response, the serving network device can send a cell handover instruction to the terminal device via air interface signaling, informing the terminal device that it can begin tracking the TRS sent by the target network device.

[0262] S305: The target network device sends a TRS according to a pre-determined tracking pattern.

[0263] S306: The terminal device tracks the TRS based on the TCI status according to a predetermined tracking mode.

[0264] On the one hand, depending on the tracking mode, the timing of when the target network device sends the TRS may differ. For example, the target network device may send the TRS after receiving the tracking indication information (e.g., Figure 6 The shown is based on the cell handover command triggering mode or Figure 8 The requested triggering mode shown is illustrated, or the target network device sends a TRS (such as...) after receiving the corresponding triggering information. Figure 7 (Examples of emergency trigger modes are shown); on the other hand, different tracking modes may result in different ways for the target network device to send TRS, for example: the target network device actively sends TRS (such as...). Figure 6 The shown is based on the cell handover command triggering mode or as follows Figure 7 (as shown in the emergency trigger mode), or, the target network device passively sends a TRS (such as...). Figure 8 (e.g., the request-triggered pattern shown).

[0265] The process of a terminal device tracking a TRS may include the following steps: receiving the TRS signal in real time and parsing key information; dynamically calibrating its own reception parameters in conjunction with the TCI status to adapt to channel changes; and continuously maintaining time-frequency synchronization with the target network device.

[0266] The communication method provided in this application is a complete end-to-end solution, which not only defines new terminal behaviors but also specifies in detail the decision-making basis and collaborative actions on the network side. For example, this application embodiment clarifies that the serving network device can decide which tracking mode to configure based on information such as the terminal device's measurement report, mobility status, service type, and historical data; at the same time, the behavior of the target network device is also precisely defined according to the different signaling received, realizing close collaboration between the terminal device and both sides of the network.

[0267] It should be noted that the execution order of S301-S306 described above is only an example, and its execution order may change under different circumstances. For example, in the emergency trigger mode, the execution order of S304 and S305 is swapped, that is, S305 is executed first and then S304 is executed. However, in the cell handover command trigger mode or the request trigger mode, the order of executing S304 first and then S305 can be maintained. As another example, the execution order of S301 and S302 is swapped, that is, S302 is executed first and then S301 is executed, or S301 and S302 are executed simultaneously, or S302 is executed slightly later than S301.

[0268] The following section uses preset tracking modes, including cell handover command trigger mode, emergency trigger mode, and request trigger mode, as examples to further describe the communication method provided in the embodiments of this application.

[0269] One possible implementation is that after activating the TCI state, the terminal device can conditionally activate the TRS (Tracking Representation System) to track the target network device based on the tracking indication information; the target network device then determines when to send the TRS based on the identification information. Another possible approach is to include the identification information in the existing XnAP message HANDOVER REQUEST.

[0270] Another possible implementation is that the target network device can determine when to send a TRS based on the identification information and the corresponding trigger information. One possible approach is to use a specific value for the trigger information: a value of 1 indicates that the target network device will immediately send a TRS, while a value of 0 indicates that the target network device will maintain the status quo (e.g., continue sending TRS, continue not sending TRS, etc.). For example, the trigger information can be carried in an existing XnAP message SN STATUSTRANSFER message. After receiving this IE, the target network device sends a TRS according to the tracking mode included in the identification information.

[0271] First, let's describe the case where the pre-determined tracking mode is based on cell handover command triggering mode. The identification information is used to instruct the target network device to prepare to send a TRS. In this case, please refer to... Figure 6 , Figure 6This is an interaction diagram of the fourth communication method provided in the embodiments of this application. The communication method provided in the embodiments of this application may include:

[0272] S501: The service network device negotiates TRS resources through the Xn interface.

[0273] S502: The serving network device sends tracking indication information to the terminal device, and the corresponding terminal device receives the tracking indication information sent by the serving network device.

[0274] After the serving network device determines the TRS resource configuration for synchronization with the candidate network device through the Xn interface, it can send an RRC reconfiguration message to the terminal device. The RRC reconfiguration message includes TCI status configuration information, which includes quasi-co-address information. This quasi-co-address information carries tracking indication information. Therefore, the serving network device can send TCI status configuration information to the terminal device via the RRC reconfiguration message, containing the newly added field TRS-ActivationTriggerCondition, which is configured only for onCSC.

[0275] The terminal device recognizes that a new field, TRS-ActivationTriggerCondition, is configured in the quasi-co-address information, and that it is configured only onCSC. Therefore, after activating the corresponding TCI state, it will not immediately track the TRS, but will only track the TRS immediately after receiving the cell handover command issued by the serving network device, according to a pre-determined tracking mode (based on the cell handover command triggering mode).

[0276] S503: The service network device receives the SSB measurement report reported by the terminal device.

[0277] S504: The serving network device determines the target network device from multiple candidate network devices.

[0278] S505: The serving network device sends an activation instruction for the TCI status of the target network device to the terminal device, and the terminal device receives the activation instruction for the TCI status.

[0279] Based on the measurement report submitted by the terminal device using SSB measurements, the serving network device determines the most suitable candidate network device for handover, which is also the target network device. Then, the serving network device activates the corresponding TCI state of the target network device via a MAC CE message.

[0280] S506: The serving network device sends a cell handover request and a pre-determined tracking mode identification information to the target network device, and the target network device receives the cell handover request and the pre-determined tracking mode identification information.

[0281] The serving network device can initiate a handover request by sending an existing XnAP message HANDOVERREQUEST message (containing the extended IE ConditionalTRSConfig of 00) to the target network device through the Xn interface.

[0282] It should be noted that S505 and S506 can be executed simultaneously, or S506 can be executed slightly later or slightly earlier than S505. The timing of "slightly later or slightly earlier" (as mentioned earlier) mentioned in this document is acceptable as long as it does not affect the coordination between the terminal device and the target network device.

[0283] S507: Terminal device activates TCI status.

[0284] S508: The target network device responds to the identification information and prepares to send a TRS.

[0285] When the target network device receives ConditionalTRSConfig as 00, it is ready to send TRS and sends a successful cell handover response to the serving network device.

[0286] S509: The target network device sends a cell handover success response to the serving network device, and the serving network device receives the cell handover success response accordingly.

[0287] S510: The serving network device sends a cell handover command to the terminal device, and the corresponding terminal device receives the cell handover command.

[0288] S511: The serving network device sends a first triggering message to the target network device, and the target network device receives the first triggering message sent by the serving network device.

[0289] The first triggering information is used to trigger the target network device to send a TRS. One possible implementation is that the first triggering information is carried in the SN STATUS TRANSFER message. The serving network device sends an existing XnAP message and an SN STATUS TRANSFER message (containing the extended IE ConditionalTRSActivation of 1) to the target network device.

[0290] One possible approach is to include an extended IE in the SN STATUS TRANSFER message. This extended IE is the aforementioned trigger information, used to inform the target network device how to send a TRS. For example, this trigger information can be placed in a field named Conditional TRSActivation. Taking the specific value of the first trigger information as 1 as an example, the configuration structure of the extended IE in the XnAP message is as follows:

[0291]

[0292] This application provides a specific network-side signaling interaction process during cell handover, extending the existing XnAP interface messages. Specifically, by extending the ConditionalTRSConfig IE to the existing XnAP message "HANDOVER REQUEST," the target gNB is informed in advance of the required TRS transmission mode; and by extending the ConditionalTRSActivation IE to the "SNSTATUS TRANSFER" message, the physical transmission of TRS is precisely triggered. This approach reuses existing signaling procedures, clarifies how the serving network device accurately notifies the target network device of the triggering conditions and activation instructions, has low overhead, is easy to implement, and ensures that the target network device only sends TRS when necessary, avoiding resource waste and guaranteeing that the terminal device can track it in real time.

[0293] It should be noted that S510 and S511 can be executed simultaneously, and S511 can be executed slightly earlier or slightly later than S510.

[0294] In one possible approach, S511 above can be omitted, and the target network device sends the TRS at the same time as or after sending the cell handover success response (S509).

[0295] S512: The target network device responds to the first trigger information by sending a TRS.

[0296] After the target network device receives a first trigger message with ConditionalTRSActivation set to 1 upon receiving a successful response to the handover request, it begins transmitting TRS on the pre-negotiated resources.

[0297] S513: Terminal devices are based on TCI status tracking (TRS).

[0298] Next, we will introduce the case where the pre-determined tracking mode is the emergency trigger mode. The identification information is used to trigger the target network device to send a TRS. In this case, please refer to... Figure 7 , Figure 7This is an interaction diagram of the fifth communication method provided in the embodiments of this application. The communication method provided in the embodiments of this application may include:

[0299] S601: The serving network device negotiates TRS resources through the Xn interface.

[0300] S602: The serving network device sends tracking indication information to the terminal device, and the corresponding terminal device receives the tracking indication information sent by the serving network device.

[0301] After the serving network device determines the TRS resource configuration for synchronization with the candidate network device through the Xn interface, it can send an RRC reconfiguration message to the terminal device. The RRC reconfiguration message includes TCI status configuration information, which includes quasi-co-address information and carries tracking indication information. Therefore, the serving network device can send TCI status configuration information to the terminal device via the RRC reconfiguration message, which includes the newly added field TRS-ActivationTriggerCondition, configuring both onCSC and emergencyTrigger.

[0302] The terminal device recognizes that a new field, TRS-ActivationTriggerCondition, is configured in the quasi-co-location information, and that both onCSC and emergencyTrigger are configured simultaneously. Therefore, after activating the corresponding TCI state, it will not immediately track the TRS. Instead, according to a pre-determined tracking mode (emergency trigger mode), it will wait to receive the cell handover command issued by the serving network device while also monitoring the signal quality of the serving network device. If an abnormal signal quality of the serving network device is detected (e.g., RSRP suddenly deteriorates sharply and falls below a pre-configured quality threshold or exceeds a configured rate of change threshold), the terminal device will immediately begin tracking the TRS of the corresponding target network device; otherwise, it will only start tracking the TRS immediately after receiving the cell handover command.

[0303] S603: The service network device receives the SSB measurement report reported by the terminal device.

[0304] S604: The serving network device determines the target network device from multiple candidate network devices.

[0305] S605: The serving network device sends an activation instruction for the TCI status of the target network device to the terminal device, and the terminal device receives the activation instruction for the TCI status.

[0306] Based on the measurement reports submitted by the terminal devices using SSB measurements, the serving network device determines the most suitable candidate network device for handover, which is also the target network device. Then, the serving network device activates the corresponding TCI state of the target network device via MAC CE.

[0307] S606: The serving network device sends a cell handover request and a pre-determined tracking mode identification information to the target network device, and the target network device receives the cell handover request and the pre-determined tracking mode identification information.

[0308] The serving network device can initiate a handover request by sending an existing XnAP message HANDOVERREQUEST (containing the extended IE ConditionalTRSConfig of 01) to the target network device through the Xn interface.

[0309] It should be noted that S605 and S606 can be executed simultaneously, or S606 can be executed slightly later or slightly earlier than S605.

[0310] S607: Terminal device activates TCI status.

[0311] S608: The target network device responds to the identification information by sending a TRS.

[0312] When the target network device receives ConditionalTRSConfig as 01, it begins transmitting TRS on the pre-negotiated resources, and executes S610 when the cell handover is successful, and executes S614 when the cell handover fails.

[0313] S609: Terminal equipment monitoring service network equipment signal quality.

[0314] S610: The target network device sends a cell handover success response to the serving network device, and the serving network device receives the cell handover success response accordingly.

[0315] S611: The serving network device sends a cell handover command to the terminal device, and the corresponding terminal device receives the cell handover command.

[0316] S612: The serving network device sends a second trigger information to the target network device. Correspondingly, the target network device receives the second trigger information sent by the serving network device and continues to send TRS.

[0317] The second triggering information is used to trigger the target network device to continue sending TRS. One possible implementation is that the second triggering information is carried in the SN STATUS TRANSFER message. The serving network device sends an existing XnAP message and an SN STATUS TRANSFER message (containing an extended IE ConditionalTRSActivation field with a value of 0) to the target network device.

[0318] It should be noted that S611 and S612 can be executed simultaneously, or S612 can be executed slightly earlier or slightly later than S611.

[0319] In one possible approach, S612 above can be omitted. After receiving the identification information, the target network device continuously sends TRS until it sends a failure response to the handover request of the serving network device, at which point the corresponding TRS transmission stops.

[0320] S613: When a terminal device receives a cell handover instruction or detects an abnormal signal quality of the serving network device, it sends a TRS based on the TCI status tracking target network device in response to the cell handover request sent by the serving network device.

[0321] While waiting to receive the cell handover command from the serving network device, the terminal device also monitors the signal quality of the serving network device. If an abnormal signal quality of the serving network device is detected (e.g., RSRP suddenly deteriorates sharply and falls below a pre-configured quality threshold or exceeds a configured rate of change threshold), the terminal device will immediately begin tracking the TRS of the corresponding target network device; otherwise, it will only start tracking the TRS after receiving the cell handover command.

[0322] S614: The target network device stops sending TRS in the event of a handover failure.

[0323] If the target network device fails to send a handover request to the serving network device, the corresponding TRS transmission stops; otherwise, if ConditionalTRSActivation is 0, TRS transmission continues.

[0324] Finally, we will discuss the case where the pre-determined tracing mode is a request-triggered mode. The identification information is used to instruct the target network device to prepare to send a TRS. In this case, please refer to... Figure 8 , Figure 8 This is an interaction diagram of the sixth communication method provided in the embodiments of this application. The communication method provided in the embodiments of this application may include:

[0325] S701: The serving network device negotiates TRS resources through the Xn interface.

[0326] S702: The serving network device sends tracking indication information to the terminal device, and the corresponding terminal device receives the tracking indication information sent by the serving network device.

[0327] After the serving network device determines the TRS resource configuration for synchronization with the candidate network device through the Xn interface, it can send an RRC reconfiguration message to the terminal device. The RRC reconfiguration message includes TCI status configuration information, which includes quasi-co-address information and carries tracking indication information. Therefore, the serving network device can send TCI status configuration information to the terminal device via the RRC reconfiguration message, which includes the newly added field TRS-ActivationTriggerCondition, configuring both onCSC and onDemandTrigger.

[0328] The terminal device recognizes that a new field, TRS-ActivationTriggerCondition, is configured in the quasi-co-location information, and that both onCSC and onDemandTrigger are configured simultaneously. Therefore, after activating the corresponding TCI state, it will not immediately track the TRS. Instead, based on a pre-determined tracking mode (based on the cell handover command triggering mode), upon receiving a cell handover command from the serving network device, the terminal device will utilize the PUCCH resource list configured for it by the network side to send a TRS transmission activation request signal on the PUCCH resource associated with the target network device to actively activate the TRS transmission. Only after this TRS transmission activation request signal is sent will the terminal device immediately track the TRS.

[0329] S703: The service network device receives the SSB measurement report reported by the terminal device.

[0330] S704: The serving network device determines the target network device from multiple candidate network devices.

[0331] S705: The serving network device sends an activation instruction for the TCI status of the target network device to the terminal device, and the terminal device receives the activation instruction for the TCI status.

[0332] Based on the measurement reports submitted by the terminal devices using SSB measurements, the serving network device determines the most suitable candidate network device for handover, which is also the target network device. Then, the serving network device activates the corresponding TCI state of the target network device via MAC CE.

[0333] S706: The serving network device sends a cell handover request and a pre-determined tracking mode identification information to the target network device, and the target network device receives the cell handover request and the pre-determined tracking mode identification information.

[0334] The serving network device can initiate a handover request by sending an existing XnAP message HANDOVERREQUEST (containing the extended IE ConditionalTRSConfig of 10) to the target network device through the Xn interface.

[0335] It should be noted that S705 and S706 can be executed simultaneously, or S706 can be executed slightly later or slightly earlier than S705.

[0336] S707: Terminal device activates TCI status.

[0337] S708: The target network device responds to the identification information, prepares to send TRS, and listens to see if it receives a TRS transmission activation request signal sent by the terminal device.

[0338] When the target network device receives ConditionalTRSConfig as 00, it is ready to send TRS and sends a successful cell handover response to the serving network device.

[0339] S709: The target network device sends a cell handover success response to the serving network device, and the serving network device receives the cell handover success response accordingly.

[0340] S710: The serving network device sends a cell handover command to the terminal device, and the corresponding terminal device receives the cell handover command.

[0341] S711: The serving network device sends a third triggering message to the target network device, and the target network device receives the third triggering message sent by the serving network device.

[0342] The third triggering information is used to instruct the target network device to continue preparing to send a TRS, so as to send a TRS when it hears a TRS transmission activation request signal sent by the terminal device. One possible implementation is that the third triggering information is carried in the SN STATUS TRANSFER message. The serving network device sends an existing XnAP message and an SNSTATUS TRANSFER message (containing an extended IE ConditionalTRSActivation field with a value of 0) to the target network device.

[0343] It should be noted that S710 and S711 can be executed simultaneously, or S711 can be executed slightly later or slightly earlier than S710.

[0344] S712: Receives the third trigger information sent by the serving network device, responds to the third trigger information, and continues to prepare to send TRS.

[0345] After the target network device receives a successful response to the handover request and receives the first trigger message with ConditionalTRSActivation set to 0, it is ready to send a TRS.

[0346] In one possible approach, S711 and S712 can be omitted, and the target network device can send the TRS after it has prepared to send the TRS and has heard the TRS transmission activation request signal sent by the terminal device.

[0347] S713: The terminal device sends a TRS transmission activation request signal to the target network device.

[0348] After receiving a cell handover command from the serving network device, the terminal device uses the PUCCH resource list configured for it by the network side to send a TRS transmission activation request signal on the PUCCH resource associated with the target network device to actively activate the TRS transmission. Only after this TRS transmission activation request signal is sent does the terminal device immediately start tracking the TRS.

[0349] S714: When the target network device detects a TRS transmission activation request signal, it sends a TRS.

[0350] S715: Terminal devices are based on TCI status tracking (TRS).

[0351] The above describes the protocol's support for multiple preset tracking modes. Service network devices or terminal devices can select one each time based on the actual situation. The aforementioned emergency trigger mode can also be used independently; that is, the protocol can specify that only the emergency trigger mode is used, or the communication protocol can only support the emergency trigger mode. In this case, the communication process can be simplified as follows: Figure 9 Please refer to the process shown. Figure 9 , Figure 9 This is an interaction diagram illustrating the seventh communication method provided in an embodiment of this application. It can be understood that... Figure 9 The terminal device in the middle can be Figure 1 Any terminal device in the context can also refer to a component within that terminal device (such as a processor, chip, or chip system). Serving network equipment and target network equipment can be... Figure 1 Any access network device, or a component within an access network device (such as a processor, chip, or chip system). Figure 9 As shown, the method includes:

[0352] S801: The serving network device sends an activation instruction for the TCI status of the target network device to the terminal device, and the terminal device receives the activation instruction for the TCI status.

[0353] S802: The serving network device sends a cell handover request to the target network device, and the target network device receives the cell handover request accordingly.

[0354] S803: Terminal device activates TCI status.

[0355] S804: The target network device responds to the cell handover request by sending a TRS.

[0356] S805: Terminal equipment monitoring service network equipment signal quality.

[0357] S806: When the target network device successfully completes the handover, it sends a cell handover success response to the serving network device, and the serving network device receives the cell handover success response.

[0358] S807: The serving network device sends a cell handover command to the terminal device.

[0359] S808: The serving network device sends a fourth trigger message to the target network device. Correspondingly, the target network device responds to the fourth trigger message sent by the serving network device and continues to send TRS. The method of sending the fourth trigger message is similar to the method of sending the second trigger message mentioned above.

[0360] It should be noted that S808 can be omitted.

[0361] S809: When a terminal device receives a cell handover command or detects an abnormal signal quality of a serving network device, it tracks the status TRS based on the TCI.

[0362] It should be noted that, Figure 9 The specific implementation methods of the communication methods shown can all be referred to the descriptions in the foregoing method embodiments, and will not be repeated here. The communication methods provided in this application embodiment are similar to... Figure 3 The difference in the communication methods shown is that the service network device and the terminal device agree in advance that the tracking mode is an emergency trigger mode. For example, the tracking mode can be agreed to be an emergency trigger mode in the protocol.

[0363] Furthermore, the aforementioned request-triggered mode can also be used alone; that is, the protocol can stipulate that only the request-triggered mode is used, or the communication protocol can support only the request-triggered mode. In this case, the communication process can be simplified as follows: Figure 9 Please refer to the process shown. Figure 10 , Figure 10 This is an interaction diagram illustrating the eighth communication method provided in this application embodiment. It can be understood that... Figure 10 The terminal device in the middle can be Figure 1Any terminal device in the context can also refer to a component within that terminal device (such as a processor, chip, or chip system). Serving network equipment and target network equipment can be... Figure 1 Any access network device, or a component within an access network device (such as a processor, chip, or chip system). Figure 10 As shown, the method includes the following steps:

[0364] S901: The serving network device sends an activation instruction for the TCI status of the target network device to the terminal device, and the corresponding terminal device receives the activation instruction for the TCI status.

[0365] S902: The serving network device sends a cell handover request to the target network device, and the target network device receives the cell handover request.

[0366] S903: Terminal device activates TCI status.

[0367] S904: The target network device responds to the cell handover request and prepares to send a TRS.

[0368] S905: When the target network device successfully completes the handover, it sends a cell handover success response to the serving network device, and the serving network device receives the cell handover success response.

[0369] S906: The serving network device sends a cell handover command to the terminal device, and the corresponding terminal device receives the cell handover command.

[0370] S907: The serving network device sends the fifth trigger information to the target network device. In response, the target network device continues to prepare to send TRS.

[0371] S908: The terminal device sends a TRS transmission activation request signal to the target network device, and the target network device listens to see if it receives the TRS transmission activation request signal.

[0372] S909: When the target network device detects a TRS transmission activation request signal, it sends a TRS.

[0373] S910: Terminal devices are based on TCI status tracking (TRS).

[0374] It should be noted that, Figure 10 The specific implementation methods of the communication methods shown can all be referred to the descriptions in the foregoing method embodiments, and will not be repeated here. The communication methods provided in this application embodiment are similar to... Figure 3The difference in the communication methods shown is that the service network device and the terminal device agree in advance that the tracking mode is a request-triggered mode. For example, the tracking mode can be agreed to be a request-triggered mode in the protocol.

[0375] It should be understood that Figures 3 to 10 The flowcharts or scene diagrams shown are for illustrative purposes only and are not intended to limit the embodiments of this application to the examples illustrated. In fact, those skilled in the art can interpret the embodiments based on... Figures 1 to 10 The examples described can be equivalently transformed to obtain more implementation methods. For instance, the emergency triggering mode and the request-based triggering mode can be combined. That is, in the aforementioned method, under the condition of satisfying the emergency triggering model, the terminal device first requests the target serving network device to send a TRS and then listens for the TRS. The target serving network device only starts sending the TRS after receiving the request from the terminal device. Of course, this variation can also be applied to the situation mentioned above where the tracking mode is determined by the serving network device or the terminal device, or to the situation where it is pre-defined in the protocol. The embodiments of this application are not limited to these.

[0376] The above text combined Figures 3 to 10 This document describes in detail the communication method provided in the embodiments of this application. The following will combine... Figures 11 to 12 The device embodiments of this application are described in detail below. It should be understood that the communication device of this application embodiment can execute the various communication methods of the foregoing embodiments of this application, that is, the specific working processes of the various products below can be referred to the corresponding processes in the foregoing method embodiments.

[0377] In the embodiments described above, the terminal device may execute some or all of the steps in each embodiment; the network device may execute some or all of the steps in each embodiment. These steps or operations are merely examples, and the embodiments of this application may also perform other operations or variations thereof. Furthermore, the steps may be executed in different orders as presented in the embodiments, and it is not necessary to execute all the operations in the embodiments of this application. Moreover, the sequence number of each step 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.

[0378] Figure 11 This is a schematic block diagram of a communication device provided in an embodiment of this application. Figure 11 As shown, the communication device 1000 may include a communication module 1020. The communication module 1020 can implement corresponding communication functions, which can be internal communication functions of the communication device 1000 or communication functions between the communication device 1000 and other devices. Optionally, the communication module 1020 may also be referred to as a communication interface or transceiver module. Optionally, the communication device 1000 further includes a processing module 1010. The processing module 1010 can implement corresponding processing functions.

[0379] Optionally, the communication device 1000 further includes a storage module, which can be used to store instructions and / or data; the processing module 1010 can read the instructions and / or data in the storage module so that the communication device 1000 can implement the aforementioned method embodiments.

[0380] In one possible design, the communication device 1000 may correspond to the terminal device in the above method embodiments, or to a component (such as a circuit, chip, or chip system) configured in the terminal device. The communication device 1000 may be used to execute the steps or processes performed by the terminal device in any of the above method embodiments.

[0381] For example, the communication module 1020 is used to receive an activation instruction for the Transmission Configuration Indicator (TCI) state of the target network device sent by the serving network device of the terminal device; the processing module 1010 is used to activate the TCI state, or to track the Tracking Reference Signal (TRS) sent by the target network device based on the TCI state according to a predetermined tracking mode. The above is only an example, and detailed steps or processes can be found in the description of the foregoing embodiments.

[0382] In one possible design, the communication device 1000 may correspond to the service network device in the above method embodiments, or to a component (such as a circuit, chip, or chip system) configured in the service network device. The communication device 1000 may be used to perform the steps or processes performed by the service network device in any of the above method embodiments.

[0383] For example, processing module 1010 is used to send a cell handover command to terminal device upon receiving a successful cell handover response from target network device; communication module 1020 is used to send an activation command for the Transmission Configuration Indicator (TCI) status of target network device to terminal device communicating with serving network device. The above is merely an example; detailed steps or processes can be found in the description of the foregoing embodiments.

[0384] In one possible design, the communication device 1000 may correspond to the target network device in the above method embodiments, or to a component (such as a circuit, chip, or chip system) configured in the target network device. The communication device 1000 may be used to perform the steps or processes performed by the target network device in any of the above method embodiments.

[0385] For example, the communication module 1020 is used to receive a cell handover request and a predetermined tracking mode identification information sent by the serving network device of the terminal device, or to send a TRS according to the predetermined tracking mode. The above is only an example; detailed steps or processes can be found in the description of the foregoing embodiments.

[0386] Figure 12 This is another schematic block diagram of a communication device provided in an embodiment of this application. The communication device 1300 may be a chip, chip system, or processor, etc., in a terminal device or network device that implements the above-described methods. The communication device 1300 can be used to implement the methods described in the above-described method embodiments; for details, please refer to the descriptions in the above-described method embodiments.

[0387] like Figure 12 As shown, the communication device 1300 may include one or more processors 1110, which may also be referred to as processing units or processing modules, and can implement certain control functions. The processor 1110 may be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, while the central processing unit can be used to control the communication device 1300 (e.g., a base station, baseband chip, user, user chip), execute software programs, and process data from the software programs.

[0388] In an alternative design, the processor 1110 may also store instructions and / or data that can be executed by the processor 1110 to cause the communication device 1300 to perform the methods described in the above method embodiments.

[0389] In another alternative design, the communication device 1300 may include a communication interface 1120 for implementing receiving and transmitting functions. For example, the communication interface 1120 may be a transceiver circuit, interface, interface circuit, or transceiver. The transceiver circuit, interface, interface circuit, or transceiver for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, interface circuit, or transceiver may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0390] Optionally, the communication device 1300 may include one or more memories 1130, which may store instructions that can be executed on the processor 1110, causing the communication device 1300 to perform the methods described in the above method embodiments. Optionally, the memories 1130 may also store data. Optionally, the processor 1110 may also store instructions and / or data. The processor 1110 and the memories 1130 may be provided separately or integrated together.

[0391] It should be understood that, in one possible design, the steps in the method embodiments provided in this application can be implemented by integrated logic circuits in the processor's hardware or by instructions in software form. The steps of the methods disclosed in the embodiments of this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, detailed descriptions are not provided here.

[0392] In one implementation, the communication device 1300 may correspond to the terminal device in the above method embodiments and may be used to execute the various steps and / or processes executed by the terminal device in the above method embodiments. The processor 1110 may be used to execute instructions stored in the memory 1130, and when the processor 1110 executes the instructions stored in the memory, the processor 1110 is used to execute the various steps and / or processes of the above method embodiments corresponding to the terminal device.

[0393] In another implementation, the communication device 1300 may correspond to the network device in the above method embodiments and may be used to execute the various steps and / or processes executed by the network device in the above method embodiments. The processor 1110 may be used to execute instructions stored in the memory 1130, and when the processor 1110 executes the instructions stored in the memory, the processor 1110 is used to execute the various steps and / or processes of the above method embodiments corresponding to the network device.

[0394] It should be understood that the aforementioned processing device can be one or more chips. For example, the processing device can be a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0395] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The 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. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as 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 linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0396] According to the method provided in the embodiments of this application, this application also provides a chip system, which includes one or more processors for calling and executing instructions stored in memory, thereby causing the method described in the embodiments of this application to be executed. The chip system may be composed of chips or may include chips and other discrete devices.

[0397] The chip system may include input circuits or interfaces for transmitting information or data, and output circuits or interfaces for receiving information or data.

[0398] According to the method provided in the embodiments of this application, this application also provides a communication system, which includes the aforementioned network device and terminal device.

[0399] According to the method provided in the embodiments of this application, this application also provides a computer program product, which includes: computer program code, which, when run on a computer, causes the computer to execute the various steps or processes executed by the network device or terminal device in any of the foregoing method embodiments.

[0400] According to the method provided in the embodiments of this application, this application also provides a computer-readable storage medium storing program code, which, when run on a computer, causes the computer to execute the various steps or processes executed by the network device or terminal device in any of the foregoing method embodiments.

[0401] The computer-readable storage medium may be the aforementioned volatile memory or non-volatile memory, or it may include both volatile memory and non-volatile memory.

[0402] In the embodiments of this application, the terms and English abbreviations are exemplary examples given for ease of description and should not be construed as limiting the application in any way. This application does not preclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0403] 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. The computer program product includes one or more computer instructions. When these computer 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.

[0404] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0405] It should be understood that in the various embodiments of this application, the sequence number of each process 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.

[0406] In summary, the above description is merely a preferred embodiment of the technical solution of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A communication method characterized by comprising: Applied to a terminal device, comprising: receiving an activation instruction of a transmission configuration indication (TCI) state of a target network device sent by a serving network device of the terminal device, wherein the target network device is a network device to which the terminal device is to be handed over, and the receiving time of the activation instruction is earlier than the sending time of a cell handover instruction; activating the TCI state; tracking a tracking reference signal (TRS) sent by the target network device based on the TCI state according to a predetermined tracking mode, wherein the predetermined tracking mode is determined from a plurality of preset tracking modes, and in any one of the plurality of preset tracking modes, the earliest sending time of the TRS is later than the sending time of the activation instruction.

2. The communication method according to claim 1, characterized by, The predetermined tracking mode is a tracking mode determined and specified by the serving network device from the plurality of preset tracking modes; or The predetermined tracking mode is a tracking mode determined by the terminal device from the plurality of preset tracking modes.

3. The communication method according to claim 2, wherein, In the case where the predetermined tracking mode is determined by the serving network device, before receiving the activation instruction of the TCI state of the target network device sent by the serving network device of the terminal device, the method further comprises: receiving tracking indication information sent by the serving network device, wherein the tracking indication information is used to indicate the predetermined tracking mode.

4. The communication method according to claim 3, characterized by, The tracking indication information is carried in a radio resource control (RRC) reconfiguration message.

5. The communication method according to any one of claims 1 to 4, characterized by, In the case where the predetermined tracking mode is an emergency triggering mode, the tracking of the TRS sent by the target network device based on the TCI state according to the predetermined tracking mode comprises: Upon receiving the cell handover instruction or monitoring signal quality anomaly of the serving network device, tracking the TRS sent by the target network device in response to a cell handover request sent by the serving network device based on the TCI state, wherein the cell handover request is sent at the same time as or after the activation instruction and before activating the TCI state.

6. The communication method according to claim 5, wherein, The signal quality anomaly includes that the signal quality is less than a quality threshold, or the change rate of the signal quality is greater than a change rate threshold.

7. The communication method according to any one of claims 1 to 4, characterized by, In the case where the predetermined tracking mode is a request triggering mode, the tracking of the TRS sent by the target network device based on the TCI state according to the predetermined tracking mode comprises: receiving the cell handover instruction; sending a TRS transmission activation request signal to the target network device; tracking the TRS based on the TCI state, wherein the TRS is sent based on responding to the TRS transmission activation request signal.

8. The communication method according to claim 7, wherein, The sending of the TRS transmission activation request signal to the target network device comprises: sending the TRS transmission activation request signal on a physical uplink control channel (PUCCH) resource associated with the target network device.

9. A communication method characterized by comprising: Applied to a serving network device, comprising: sending, to a terminal device in communication with the serving network device, an activation instruction of a transmission configuration indication (TCI) state of a target network device, wherein the target network device is a network device to which the terminal device is to be handed over; sending, to the target network device, a cell handover request and identification information of a predetermined tracking mode, wherein the predetermined tracking mode is one determined from a plurality of preset tracking modes, and there are at least two preset tracking modes corresponding to different transmission occasions of tracking reference signals (TRSs); in a case where a cell handover success response sent by the target network device is received, sending, to the terminal device, a cell handover instruction.

10. The communication method according to claim 9, wherein, The predetermined tracking mode is a tracking mode determined and specified by the serving network device from the plurality of preset tracking modes; or The predetermined tracking mode is a tracking mode determined by the terminal device from the plurality of preset tracking modes.

11. The communication method according to claim 10, wherein, In a case where the predetermined tracking mode is determined by the serving network device, the method further includes: determining the predetermined tracking mode from the plurality of preset tracking modes according to one or more of wireless channel and link quality information, terminal information, a service type, network topology information, and historical data of the terminal device.

12. The communication method according to claim 10, wherein, In a case where the predetermined tracking mode is determined by the serving network device, before the activation instruction of the TCI state of the target network device is sent to the terminal device in communication with the serving network device, the method further includes: sending, to the terminal device, tracking indication information, wherein the tracking indication information is used to indicate the predetermined tracking mode, and the tracking indication information corresponds to the identification information.

13. The communication method according to claim 12, wherein, The tracking indication information is carried in a radio resource control (RRC) reconfiguration message.

14. The communication method according to any one of claims 9 to 13, characterized by, The cell handover request and the identification information are carried in a HANDOVER REQUEST message.

15. The communication method according to any one of claims 9-13, characterized by, In a case where the predetermined tracking mode is a cell handover instruction triggered mode, the identification information is used to indicate that the target network device is ready to send the TRS, and the method further includes, at the same time or after the cell handover instruction is sent to the terminal device: sending, to the target network device, first trigger information, wherein the first trigger information is used to trigger the target network device to send the TRS.

16. The communication method according to claim 15, wherein The first trigger information is carried in an SN STATUS TRANSFER message.

17. The communication method according to any one of claims 9-13, characterized by, In a case where the predetermined tracking mode is an emergency trigger mode, the identification information is used to trigger the target network device to send the TRS, and the method further includes, at the same time or after the cell handover instruction is sent to the terminal device: sending, to the target network device, second trigger information, wherein the second trigger information is used to trigger the target network device to continue to send the TRS.

18. The communication method according to any one of claims 9-13, characterized by, In a case where the predetermined tracking mode is a request type trigger mode, the identification information is used to instruct the target network device to be ready to send the TRS, and the method further comprises: sending third trigger information to the target network device, wherein the third trigger information is used to instruct the target network device to continue to be ready to send the TRS, so as to send the TRS when the TRS transmission activation request signal sent by the terminal device is listened to.

19. A method of communication, comprising: The target network device is applied to, and the target network device is a network device to be switched by a terminal device, and comprises: receiving a cell switching request and identification information of a predetermined tracking mode sent by a serving network device of the terminal device, wherein the predetermined tracking mode is determined from a plurality of preset tracking modes, and the transmission time of a tracking reference signal (TRS) corresponding to at least two preset tracking modes is different; sending the TRS according to the predetermined tracking mode; wherein the time at which the terminal device receives an activation instruction of a transmission configuration indication (TCI) state is earlier than the sending time of a cell switching instruction, and the sending time of the TRS is later than the sending time of the activation instruction.

20. The communication method according to claim 19, wherein, In a case where the predetermined tracking mode is a cell switching instruction based trigger mode, the sending of the TRS according to the predetermined tracking mode comprises: in response to the identification information, being ready to send the TRS; receiving first trigger information sent by the serving network device, wherein the sending time of the first trigger information is later than or equal to the time at which the serving network device sends a cell switching instruction to the terminal device; in response to the first trigger information, sending the TRS.

21. The communication method according to claim 19, wherein, In a case where the predetermined tracking mode is an emergency trigger mode, the sending of the TRS according to the predetermined tracking mode comprises: in response to the identification information, sending the TRS; in a case of successful switching, receiving second trigger information sent by the serving network device, and continuing to send the TRS.

22. The communication method according to claim 21, wherein, The sending of the TRS according to the predetermined tracking mode further comprises: in a case of failed switching, stopping sending the TRS.

23. The communication method of claim 19, wherein, In a case where the predetermined tracking mode is a request type trigger mode, the sending of the TRS according to the predetermined tracking mode comprises: in response to the identification information, being ready to send the TRS; after sending a cell switching success response, receiving third trigger information sent by the serving network device, and in response to the third trigger information, continuing to be ready to send the TRS; listening to whether a TRS transmission activation request signal sent by the terminal device is received; in a case where the TRS transmission activation request signal is listened to, sending the TRS.

24. A method of communication, comprising: The terminal device is applied to, and comprises: receiving an activation instruction of a transmission configuration indication (TCI) state of a target network device sent by a serving network device of the terminal device, wherein the target network device is a network device to be switched by the terminal device; activating the TCI state; tracking a tracking reference signal (TRS) transmitted by the target network device based on the TCI state, in a case where a cell switching instruction transmitted by the serving network device is received or signal quality of the serving network device is monitored to be abnormal.

25. A method of communication, comprising: Applied to a serving network device, comprising: sending, to a terminal device in communication with the serving network device, an activation instruction of a transmission configuration indication (TCI) state of a target network device, wherein the target network device is a network device to which the terminal device is to be switched; sending, to the target network device, cell switching request identification information; sending, to the terminal device, a cell switching instruction in a case where a cell switching success response transmitted by the target network device is received; sending, to the target network device, fourth trigger information, wherein the fourth trigger information is used to trigger the target network device to continue transmitting a tracking reference signal (TRS).

26. A method of communication, comprising: Applied to a target network device, comprising: receiving, by a terminal device, a cell switching request transmitted by a serving network device; transmitting, in response to the cell switching request, a tracking reference signal (TRS); in a case where switching is successful, continuing to transmit the TRS in response to fourth trigger information transmitted by the serving network device; wherein a time at which the terminal device receives an activation instruction of a TCI state is earlier than a sending time of a cell switching instruction, and a sending time of the TRS is later than a sending time of the activation instruction.

27. A method of communication, comprising: Applied to a terminal device, comprising: receiving, by a terminal device, an activation instruction of a transmission configuration indication (TCI) state of a target network device transmitted by a serving network device, wherein the target network device is a network device to which the terminal device is to be switched; activating the TCI state; receiving a cell switching instruction transmitted by the serving network device; sending, to the target network device, a tracking reference signal (TRS) transmission activation request signal; tracking the TRS based on the TCI state, wherein the TRS is transmitted based on a response to the TRS transmission activation request signal.

28. A method of communication, comprising: Applied to a serving network device, comprising: sending, to a terminal device in communication with the serving network device, an activation instruction of a transmission configuration indication (TCI) state of a target network device, wherein the target network device is a network device to which the terminal device is to be switched; sending, to the target network device, a cell switching request; sending, to the terminal device, a cell switching instruction in a case where a cell switching success response transmitted by the target network device is received; sending, to the target network device, fifth trigger information, wherein the fifth trigger information is used to instruct the target network device to continue to be prepared to transmit a tracking reference signal (TRS) so as to transmit the TRS when a TRS transmission activation request signal transmitted by the terminal device is listened to.

29. A method of communication, comprising: Applied to a target network device, comprising: receiving, by a terminal device, a cell switching request transmitted by a serving network device; being prepared to transmit a tracking reference signal (TRS) in response to the cell switching request; After sending the cell handover success response, in response to fifth trigger information sent by the service network device, continue to prepare to send the TRS; Listen whether a TRS transmission activation request signal sent by the terminal device is received; In the case of listening to the TRS transmission activation request signal, send the TRS; Wherein, the time of the terminal device receiving the activation instruction of the TCI state is earlier than the sending time of the cell handover instruction, and the sending time of the TRS is later than the sending time of the activation instruction.

30. A communications device, characterized by The apparatus comprises at least one processor coupled with a memory; and the at least one processor is configured to perform the method of any one of claims 1 to 29. The apparatus comprises at least one processor coupled with a memory; and the at least one processor is configured to perform the method of any one of claims 1 to 29.

Images