Link report method and user equipment

Abstract

The present disclosure provides a link report method and a user equipment. The link report method is performed by a user equipment (UE), comprising: determining whether a link failure occurs by a UE configured with a conditional layer 1 / layer 2 triggered mobility (CLTM) or a UE performing a CLTM procedure; and saving link failure related information in a UE variable for saving link failure information by the UE in a case of determining that the link failure occurs, the link failure related information comprising information related to corresponding CLTM characteristics.

Description

Technical Field

[0001] This disclosure relates to the field of wireless communication technology, and more specifically, to a link reporting method and corresponding user equipment. Background Technology

[0002] In wireless networks, network optimization can improve network performance. This typically involves data collection and analysis of existing deployed and operational networks to identify factors affecting network quality, and then improving performance by modifying configured network parameters, adjusting network structure, and deploying equipment. Self-configuration and Self-Optimization Network (SON) refers to the process of automatically adjusting the network based on user equipment and / or base station measurements / performance measurements. The network side can configure the UE to perform measurements for SON. SON functions include many aspects, such as Automatic Neighbor Relation Function (ANR) to reduce the operator's neighbor cell management burden, Mobility Load Balancing (MLB) to balance the workload between different cells, Mobility Robustness Optimization (MRO) to optimize mobility performance, Random Access Channel Optimization (RAR) to optimize random access channel parameters, and Radio Link Failure Reporting (RFL) to optimize coverage and MRO.

[0003] In NR systems, Radio Link Failure (RLF) reports record relevant information about link failures on the UE side, which is then used by the network side to diagnose and optimize issues or parameters such as network coverage, mobility robustness parameters, and random access procedure configuration. Successful Handover Reports (SHR) record information related to a successful handover, which is then used by the network side to further optimize mobility performance during suboptimal handovers.

[0004] Version 18 of the NR system introduced a Layer 1 / L2-triggered mobility (LTM) mechanism. The purpose of this mechanism is to reduce mobility latency. In LTM, the RRC configuration of the target candidate cell is sent to the UE in advance. Subsequently, based on Layer 1 measurement results, the network side triggers cell changes via Layer 1 or Layer 2 signaling, thereby reducing latency, overhead, and downtime. Version 19 of the NR system introduced a condition-based LTM mechanism to further improve the robustness of the LTM process.

[0005] This disclosure aims to address the SON reporting issue in NR networks, and further, to address the SON reporting issue in networks supporting Conditional LTM (CLTM). Summary of the Invention

[0006] The main objective of this disclosure is to provide a link reporting method executed by a user equipment and the user equipment itself, so as to enable the setting and reporting of condition-based LTM-related information in a system that supports condition-based LTM.

[0007] According to a first aspect of this disclosure, a link reporting method executed by a user equipment is provided, comprising: a UE configured with condition-based Layer 1 or Layer 2 triggered mobility CLTM or having performed a CLTM procedure determining whether a link failure has occurred; and, if the UE determines that a link failure has occurred, storing link failure-related information in a UE variable used for storing link failure information, the link failure-related information including information related to the corresponding CLTM feature.

[0008] According to a second aspect of this disclosure, a link reporting method executed by a user equipment is provided, comprising: a UE configured with condition-based Layer 1 or Layer 2 triggered mobility CLTM or having performed a CLTM procedure determining whether a successful handover or cell change procedure has been performed; and, if the UE determines that a successful handover or cell change procedure has been performed, performing a successful handover report (SHR) determination procedure, wherein if a given condition is met, successful handover information or successful cell change information is stored in an SHR variable.

[0009] According to a third aspect of this disclosure, a user equipment is provided, comprising: a processor; and a memory storing instructions; wherein the instructions, when executed by the processor, perform the aforementioned link reporting method.

[0010] Invention Effects

[0011] According to the link reporting method and user equipment disclosed herein, in a CLTM-supporting system, when a CTLM-configured UE experiences an RLF (Recurrent Link Failure) or a CLTM execution process fails, it aims to report information related to CLTM-based link failures or cell change failures. This allows the network side to determine the cause of the link failure based on the received CLTM-related information and optimize the settings of relevant mobility parameters to avoid or reduce link failures or CLTM execution failures. Furthermore, when a CLTM-configured UE executes a successful CLTM process, if the process is not optimal or is a near failure, according to the method described in this disclosure, the UE can trigger the recording of relevant cell change information during the CLTM process in the SHR (Site Change Registry). This allows the network side to optimize the configuration and performance of subsequent CLTM processes based on the information recorded by the UE. Attached Figure Description

[0012] The above and other features of this disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0013] Figure 1 This is a schematic flowchart illustrating the cell switch process based on the CLTM mechanism.

[0014] Figure 2 This is a schematic flowchart illustrating one implementation of the link reporting method in this disclosure.

[0015] Figure 3 This is a schematic flowchart illustrating another implementation of the link reporting method in this disclosure.

[0016] Figure 4 A block diagram of a user equipment according to an embodiment of the present disclosure is shown. Detailed Implementation

[0017] Other aspects, advantages, and key features of this disclosure will become apparent to those skilled in the art from the following detailed description of exemplary embodiments of the disclosure taken in conjunction with the accompanying drawings.

[0018] In this specification, the various embodiments described below to illustrate the principles of this disclosure are merely illustrative and should not be construed as limiting the scope of the disclosure in any way. The following description, with reference to the accompanying drawings, is intended to aid in a comprehensive understanding of exemplary embodiments of this disclosure as defined by the claims and their equivalents. The following description includes various specific details to aid understanding, but these details should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Furthermore, for clarity and brevity, descriptions of well-known functions and structures have been omitted. Additionally, throughout the drawings, the same reference numerals are used for similar functions and operations.

[0019] In this disclosure, the terms “comprising” and “containing” and their derivatives are used to mean including rather than limiting; the term “or” is inclusive and means and / or. “If,” “if,” “in the case of,” and “when” are interchangeable.

[0020] The following describes several implementations of this disclosure using NR mobile communication systems and their subsequent evolutions as example application environments. However, this disclosure is applicable to many other wireless communication systems. Unless otherwise specified, the concepts of cell and base station are interchangeable; a cell can also be a cell under any of the above-mentioned types of base stations, and unless otherwise specified, cell, beam, and transmission point (TRP) are interchangeable. A handover command and a Radio Resource Control (RRC) message containing a handover command are equivalent, referring to an RRC message that triggers the UE to perform a handover or the configuration within an RRC message. Cancel, release, delete, clear, and clear are interchangeable. Execute, use, and apply are interchangeable. Configure and reconfigure are interchangeable. Monitor and detect are interchangeable. Initiate and trigger are interchangeable. Information elements or fields are interchangeable. Handover and synchronous reconfiguration of the MCG are equivalent. The names of the information elements are case-insensitive.

[0021] The following section will first describe some existing mechanisms / prior technologies involved in this disclosure. It is worth noting that some names used in the following description are merely illustrative and not restrictive, and may be used in other ways.

[0022] The existing wireless link failure reporting mechanism:

[0023] In NR systems, the UE generates and saves a Radio Link Failure (RLF) report when a Radio Link Failure (RLF) or Handover Failure (HOF) occurs, storing the RLF information in the UE variable VarRLF-Report. Generally, the UE only saves the RLF information for the most recent connection failure (RLF or HOF) in the RLF report. After restoring connection with the network (e.g., through an RRC re-establishment procedure or an RRC establishment procedure for establishing a new connection), the UE can inform the network via an RRC message that it has a valid Radio Link Failure report (e.g., indicated by the rlf-InfoAvailable information element). Upon receiving this indication, the network can request the UE to report its saved Radio Link Failure report via an RRC message (e.g., indicated by the rlf-ReportReq information element in the UEInformationRequest message). The UE will then report the saved RLF report (the rlf-Report information element in the UEInformationResponse message) to the network in its RRC response message. The radio link failure reports obtained by the network side are used for network optimization, such as network coverage and mobility robustness optimization. The RLF report contains information related to link failure, including the identifiers and measurement results of the source cell, target cell, or neighboring cell at the time of the link failure, location information, link failure type (RLF or HOF), RLF reason, the time elapsed from connection failure to RLF report submission (denoted by the timeSinceFailure information element), the time elapsed from the most recent receipt of a handover command (handover initiation or handover execution) to connection failure (denoted by the timeConnFailure information element), the time between the connection failure and the next UE entering the RRC connected state after the reconnection process fails (denoted by the timeUntilReconnection information element), the RRC reconnection cell identifier, and random access procedure information executed before the link failure. RLF and HOF are collectively referred to as connection failure or link failure.

[0024] Successfully switched to SHR report:

[0025] Version 17 of the NR system introduces a Successful Handover Information Report (SHR) to provide the network with mobility information related to a successful handover process. This allows the network to further optimize mobility parameter configurations based on the information reported by the UE, improving handover performance, such as reducing handover latency. The SHR may include one or more of the following: UE Radio Network Temporary Identifier (C-RNTI), source cell identifier, target cell identifier, measurement results of the source or target cell, neighbor cell measurement results, the reason for triggering the successful handover information report (i.e., which triggering condition was met), random access procedure information, and location information. A successful handover includes the successful transmission of an RRC reconfiguration completion message in response to the handover command RRC reconfiguration message at the target base station, or the successful completion of the random access procedure to the target base station by the MAC layer. The network side configures information for triggering SHR (such as threshold values ​​corresponding to T310, T312, and T304, referred to as SHR configuration (e.g., the successHO-config information element). The UE will only activate the corresponding UE change function in the SHR when one or more trigger conditions according to the configured trigger information are met (e.g., when a handover command is received or during handover, the percentage of the operating value of the source cell's T310 (or T312) to its configured value exceeds the configured threshold value; when handover is successfully completed, the percentage of the operating value of T304 to its configured value exceeds the configured threshold value; or during the dual-activation protocol stack (DAPS) handover execution (when timer T304 is running) the source cell experiences an RLF). The successful handover information is recorded in a data set (such as VarSuccessHO-Report). The UE can inform the network side via an RRC message that it has an available successful handover report (such as indicated by the successHO-InfoAvailable information element). Upon receiving the indication, the network side can request the UE to report its saved successful handover information report via an RRC message (such as the successHO-ReportReq indication in the UEInformationRequest message). The UE will then report the saved successful handover report (successHO-Report in the UEInformationResponse message) to the network side in its RRC response message.

[0026] LTM and CLTM mechanisms:

[0027] To reduce data interruptions caused by cell handover, the 3GPP working group introduced the LTM (Last Term Indicator) mechanism. LTM can be used for serving cell changes within the Master Cell Group (MCG), such as changes to the Primary Cell (PCell), and also for serving cell changes within the Secondary Cell Group (SCG). Cell changes using the LTM mechanism are called cell switches, to distinguish them from traditional handover. Figure 1 As shown, the network side sends the LTM candidate cell configuration (each candidate cell is identified by a candidate identifier ltm-CandidateId) to the UE in advance via RRC signaling (such as an RRC reconfiguration message). Upon receiving the configuration, the UE saves the received LTM candidate cell configuration. The candidate cell configuration includes the RRC configuration corresponding to one or more candidate cells (such as an RRC reconfiguration message containing synchronization reconfiguration information elements). Based on the Layer 1 measurement results reported by the UE, the network side determines the final target cell and triggers the cell switch procedure via the LTM Cell Switch Command MAC control element (CE). The MAC signaling used to trigger the cell switch procedure contains at least the indication information of the target candidate cell configuration (such as being included in the Target Configuration ID field, the value of which is set to the candidate identifier ltm-CandidateId corresponding to the target cell minus one). The UE triggers the cell switch procedure, starts timer T304, and applies the saved previously received LTM candidate cell configuration to perform the change procedure to the target cell. If timer T304 times out, the UE considers the LTM cell change procedure to have failed.

[0028] To further enhance its robustness, the NR system introduces a condition-based LTM mechanism based on the LTM mechanism.

[0029] Condition-Based Link Switching (CLTM) can be divided into three phases: CLTM configuration, CLTM condition evaluation, and CLTM execution. In the CLTM configuration phase, when the network configures the UE with RRC configurations for one or more target candidate cells (including at least the corresponding RRC reconfiguration messages), each (or at least some) of these target candidate cells is associated with an execution condition configuration. The execution condition configuration can be associated with one or more measurement events (e.g., by configuring measurement identifiers). In the CLTM condition evaluation phase, the UE monitors the link quality of one or more CLTM candidate cells based on the associated measurement events. When the UE determines that all the execution conditions configured for one or more candidate cells are met, the UE identifies a target cell and enters the CLTM execution phase, i.e., executes the cell switch procedure for that target cell, applying the RRC configuration of that target candidate cell without requiring a cell change command to trigger it. Therefore, CLTM is a cell switching process where the network controls the UE's decision-making. CLTM execution conditions can be configured based on Layer 1 or Layer 3 measurement configurations. When the execution conditions of a CLTM candidate are based on Layer 1 measurements, it is called a Layer 1 CLTM candidate (cell), and the corresponding LTM execution becomes a Layer 1 CLTM (execution). When the execution conditions of a CLTM candidate are based on Layer 3 measurements, it is called a Layer 3 CLTM candidate (cell), and the corresponding LTM execution becomes a Layer 3 CLTM (execution). For Layer 1 CLTM candidates, the condition evaluation operation is performed by the Media Access Control (MAC) layer, while for Layer 3 CLTM candidates, the condition evaluation operation is performed by the RRC layer.

[0030] Furthermore, both LTM and CLTM support early uplink synchronization, meaning that uplink synchronization information for one or more candidate cells is obtained in advance before cell change is triggered. For example, in the CLTM mechanism, the network side triggers early uplink synchronization for a CLTM candidate cell via a Physical Downlink Control Channel (PDCCH) command. The PDCCH command at least includes the identifier / indicator of the candidate cell and the corresponding random access preamble resource indication. The UE then sends a random access preamble to the CLTM candidate cell. At a later time, the network side informs the UE of the timing advance (TA) value of the candidate cell via an early uplink synchronization TAC MAC CE (such as the LTM Candidate Timing Advance Command MAC CE). Upon receiving the TAC MAC CE, the UE starts an early uplink synchronization time alignment timer (TAT) (such as the ltm-Candidate-TimeAlignmentTimer) for the corresponding candidate cell. During the TAT operation, the UE considers itself to be uplink synchronized with the candidate cell. If the TAT times out, it considers itself to be uplink out of sync with the candidate cell. If a cell change process to the candidate cell is subsequently triggered, the UE can determine whether to access the cell via non-random access or random access based on whether it is in an uplink synchronized state.

[0031] In the SON function of version 19, the LTM mechanism of version 18 has been enhanced, including the introduction of LTM-related SON information in the RLF report or SHR. Therefore, in NR systems that have introduced the CLTM mechanism, how to implement the SON function, that is, how to record and set the SON information in the RLF report or SHR when the UE is configured with CLTM or performs the CLTM procedure, is the issue of concern in this disclosure.

[0032] Figure 2 This is a schematic flowchart illustrating one implementation of the link reporting method in this disclosure. This implementation will be described below.

[0033] In this implementation, when an RLF or HOF occurs, the UE configured with CLTM or the UE that has performed the CLTM procedure records the corresponding CLTM-specific SON information in the RLF report of the corresponding link failure event, and reports it to the network side via a UEInformationResponse message during the subsequent UEInformation process. Each operation in this method is performed when the UE supports RLF reporting for CLTM. This method includes one or more of the following steps.

[0034] Step 210: The UE determines whether a link failure has occurred.

[0035] Furthermore, the link failure is an RLF (Recurrent Link Failure) of the primary cell group, or an RRC (Recurrent Reconfiguration) failure (such as a handover failure or an LTM (including CLTM) cell change process failure). Optionally, a synchronization reconfiguration failure generally refers to the timer T304 used to monitor the synchronization reconfiguration process timeout. Therefore, a CLTM cell change failure can also be replaced by an RRC synchronization reconfiguration failure.

[0036] Step 220: In the event of a link failure, store the link failure-related information in the UE variable used for storing link failure information. This link failure-related information includes information related to the corresponding CLTM feature. Optionally, this UE variable is a VarRLF-Report.

[0037] The step of storing link failure information in UE variables may include one or more of the following operations:

[0038] Operation 1: Set the first information to indicate that the UE was in uplink synchronization with the target cell before the link failure occurred or before the CLTM cell change procedure was executed. Optionally, the target cell refers to the target cell of the CLTM cell change procedure, and the link failure refers to the failure of the CLTM cell change procedure. Optionally, it can also be expressed as the first information indicating whether the UE had an early uplink synchronization up-alignment timer (TAT) corresponding to the target cell that was in operation before the link failure occurred or before the CLTM cell change procedure was executed; or the first information indicating whether the UE received a timing advance command (TAC) for early uplink synchronization of the target cell before the link failure occurred or before the CLTM cell change procedure was executed; or the first information indicating whether the UE performed early uplink synchronization before the link failure occurred or before the CLTM cell change procedure was executed. Optionally, operation 1 is performed when one or more of the following conditions are met: the link failure in step 210 is a CLTM cell change failure; the CLTM cell change process is based on a random access procedure (RACH-based); the UE performed early uplink synchronization on the target cell before the link failure occurred or before performing the CLTM cell change process. Optionally, the following can be replaced: early uplink synchronization was performed on the target cell; the early uplink synchronization TAT associated with the target cell was running / was running; or a TAC MAC CE for early uplink synchronization of the target cell was received. The early uplink TAC MAC CE for the target cell refers to a received TAC MAC CE associated with the target cell or a TAC MAC CE containing the candidate identifier ltm-CandidateId or target configuration identifier Target Configuration ID associated with the target cell. Optionally, the value of the target configuration identifier Target Configuration ID of the target cell is set to the candidate identifier ltm-CandidateId of the target cell minus one.

[0039] Operation 2: Set the second information, which represents the time elapsed from the early uplink synchronization TAT timeout corresponding to the target cell to the execution of the failed CLTM cell change process or the fulfillment of (all) execution conditions corresponding to the failed CLTM cell change. Optionally, the early uplink synchronization TAT timeout corresponding to the target cell refers to the most recent early uplink synchronization TAT timeout corresponding to the target cell before the CLTM cell change (execution or failure), because before the CLTM cell change, the early uplink synchronization TAT corresponding to the target cell may have been started / run / timed out multiple times.

[0040] Operation 3: Set the third piece of information, representing the time elapsed from the initiation of the early uplink synchronization TAT corresponding to the target cell (or the receipt of the early uplink synchronization TAC MAC CE corresponding to the target cell) to the execution of the failed CLTM cell change process or the fulfillment of (all) execution conditions corresponding to the failed CLTM cell change. Optionally, the initiation of the early uplink synchronization TAT corresponding to the target cell refers to the most recent initiation of the early uplink synchronization TAT corresponding to the target cell before the CLTM cell change (execution or failure), because before the CLTM cell change, the early uplink synchronization TAT corresponding to the target cell may have been initiated / run / timed out multiple times. Therefore, optionally, the early uplink synchronization TAC MAC CE corresponding to the target cell also refers to the most recent early uplink synchronization TAC MAC CE corresponding to the target cell.

[0041] Operation 4: The UE sets the value of the fourth information to indicate that the TA value used / applied in the CLTM cell change procedure was obtained through network signaling. Optionally, further, it is obtained through Early Uplink Synchronization TAC MAC CE (i.e., LTM Candidate Timing Advance Command MAC CE) signaling. Optionally, the fourth information is the timingAdvanceEstType information element; optionally, in this operation, the value of this information element is set to nw. Optionally, this operation is performed when the failed CLTM cell change procedure is a RACH-less procedure. Optionally, this operation is performed when there is an Early Uplink Synchronization TAT corresponding to the target cell when the CLTM cell change procedure is executed or triggered; that is, the target cell is in an uplink synchronized state. Optionally, operations 2 and 3 are performed when operation 4 is executed.

[0042] Operation 5: If the last RRC reconfiguration message containing synchronization reconfiguration executed by the UE was about a CLTM cell change, then the UE sets the value of the fifth information to indicate that the type of the last cell change executed by the UE was CLTM. Optionally, otherwise, if the last RRC reconfiguration message containing synchronization reconfiguration executed by the UE was about an LTM cell change, then the UE sets the value of the fifth information to indicate that the type of the last cell change executed by the UE was LTM. Optionally, the fifth information is the lastHOtype information element. Optionally, the UE performs this operation 5 when the connection failure information element (connectionFailureType) is set to radio link failure (rlf) or handover failure (hof). Optionally, the UE performs this step 5 when it received an RRC reconfiguration message containing synchronization reconfiguration before the connection failure. Optionally, the UE performs this operation when it supports the RLF reporting function for CLTM.

[0043] Operation 6: If the UE has saved CLTM configuration information, then the UE includes the execution condition configuration corresponding to one or more CLTM candidate cells in the RLF report. Optionally, for a neighboring cell, if it is a CLTM candidate cell, and if its corresponding execution condition is based on Layer 1 conditions, then the execution condition corresponding to the candidate cell is included in the information element (such as measResultL1NeighCells) used to record Layer 1 measurement results; if its corresponding execution condition is based on Layer 3 conditions, then the execution condition corresponding to the candidate cell is included in the information element (such as measResultNeighCells) used to record Layer 3 measurement results. Optionally, the UE performs Operation 6 on one or more neighboring cells with available measurement results.

[0044] According to the above link reporting method, in a system that supports CLTM, when a UE configured with CTLM experiences an RLF or the CLTM execution process fails, it is possible to report relevant information about CLTM-based link failure or cell change failure. This allows the network side to determine the cause of the link failure based on the received CLTM-related information and optimize the settings of relevant mobility parameters to avoid or reduce link failure or CLTM execution failure.

[0045] Figure 3 This is a schematic flowchart illustrating another implementation of the link reporting method in this disclosure. This implementation will be described below.

[0046] In this implementation, when a successful handover or cell change occurs, the UE configured with CLTM or the UE that has performed the CLTM procedure records the corresponding CLTM-specific SON information in the SHR report of the successful cell change / handover event, and reports it to the network side via a UEInformationResponse message during the subsequent UE information process. Each operation in this method is performed when the UE supports SHR for CLTM. This method includes one or more of the following steps.

[0047] Step 310: The UE determines whether a successful handover or cell change process has been performed.

[0048] Optionally, the successful handover or cell change process is a random access procedure triggered by the successful completion of the Medium Access Control (MAC) layer, or it is the receipt of an indication from a lower layer that the LTM / CLTM cell change execution has been successfully completed.

[0049] Step 320: When a successful handover or cell change procedure is performed, the SHR determination procedure is executed. In the SHR determination procedure, the UE performs one or more of the following operations.

[0050] Operation 1: If the following conditions are met, the UE saves successful handover / cell change information in the SHR variable (such as VarSuccessHO-Report): (1) The successful cell change is a CLTM process based on random access; (2) Before the cell change process, the early uplink synchronization (TAT) corresponding to the target cell is in operation. This operation defines an SHR trigger condition. When the trigger condition is met, the UE records the relevant SHR information of the corresponding cell change process. In this operation, the SHR trigger condition can also be understood as the CLTM cell change process changing from a process that should have been RACH-less to a process based on random access.

[0051] Operation 2: If the following conditions are met, the UE saves the successful handover / cell change information in the SHR variable: (1) The successful cell change performed is a CLTM process without random access; (2) During the cell change process (such as when the T304 timer is running), the early uplink synchronization TAT corresponding to the target cell times out. Another SHR triggering condition is defined in this operation.

[0052] Operation 3: If the following conditions are met, the UE saves the successful handover / cell change information in the SHR variable: (1) The successful cell change is a CLTM process without random access; (2) When the cell change process is triggered / executed, the early uplink synchronization TAT corresponding to the target cell is in running state; (3) When the cell change process is triggered / executed, the running value of the early uplink synchronization TAT corresponding to the target cell exceeds / is less than a configured threshold value TH1, and the remaining value of the TAT is less than a configured threshold value TH2. Another SHR triggering condition is defined in this operation. For example, if the value of the TAT is configured to 100ms, when the cell change process is triggered, if the running value of the TAT is 95, exceeding the configured threshold value 80, or the remaining value of the TAT is only 5, less than the configured threshold value 20, then the UE triggers the SHR recording / saving operation.

[0053] Operation 4: Set first information to indicate that the UE was in uplink synchronization with the target cell before / when the cell change was initiated. Optionally, the target cell refers to the target cell of the CLTM cell change process. Optionally, it can also be expressed as the first information indicating that the UE had an early uplink synchronization (TAT) corresponding to the target cell that was in operation before executing the CLTM cell change process; or the first information indicating that the UE received a Timing Advance Command (TAC) for early uplink synchronization of the target cell before executing the CLTM cell change process; or the first information indicating that the UE performed early uplink synchronization before executing the CLTM cell change process. Optionally, this operation 4 is performed when one or more of the following conditions are met: the successful cell change is a CLTM cell change; the CLTM cell change process is based on a random access procedure (RACH-based); the UE performed early uplink synchronization with the target cell before executing the CLTM cell change process. Optionally, the following can be replaced: early uplink synchronization was performed on the target cell; the early uplink synchronization TAT associated with the target cell was previously running / was previously running; and a TAC MAC CE for early uplink synchronization of the target cell was previously received. The early uplink TAC MAC CE for the target cell refers to a received TAC MAC CE associated with the target cell or a TAC MAC CE containing the candidate identifier ltm-CandidateId or target configuration identifier Target Configuration ID associated with the target cell. Optionally, the value of the target configuration identifier Target Configuration ID of the target cell is set to the candidate identifier ltm-CandidateId of the target cell minus one.

[0054] Operation 5: Set the second information, which represents the time elapsed from the early uplink synchronization TAT timeout corresponding to the target cell to the successful execution of the CLTM cell change process or the fulfillment of (all) execution conditions corresponding to the successful CLTM cell change. Optionally, the early uplink synchronization TAT timeout corresponding to the target cell refers to the most recent early uplink synchronization TAT timeout corresponding to the target cell before the CLTM cell change execution, because before the CLTM cell change, the early uplink synchronization TAT corresponding to the target cell may have been started / run / timed out multiple times.

[0055] Operation 6: Set the third piece of information, representing the time elapsed from the initiation of the early uplink synchronization TAT corresponding to the target cell (or the receipt of the early uplink synchronization TAC MAC CE corresponding to the target cell) to the successful execution of the CLTM cell change process or the fulfillment of (all) execution conditions corresponding to the successful CLTM cell change. Optionally, the initiation of the early uplink synchronization TAT corresponding to the target cell refers to the most recent initiation of the early uplink synchronization TAT corresponding to the target cell before the CLTM cell change execution. This is because before the CLTM cell change, the early uplink synchronization TAT corresponding to the target cell may have been initiated / run / timed out multiple times. Therefore, optionally, the early uplink synchronization TAC MAC CE corresponding to the target cell also refers to the most recent early uplink synchronization TAC MAC CE corresponding to the target cell.

[0056] Operation 7: If the successful handover / cell change is a CLTM cell change, then set the fourth information to indicate that the handover / cell change is a CLTM cell change process. Optionally, the successful handover / cell change being a CLTM cell change can be described as the target cell of the cell change being a CLTM candidate cell.

[0057] Operation 8: For a neighboring cell, if it is a CLTM candidate cell, the value of the fifth information is set to true to indicate that the neighboring cell is a CLTM candidate cell. Optionally, otherwise, if it is an LTM candidate cell, the UE sets the value of the sixth information to true to indicate that the neighboring cell is an LTM candidate cell. Optionally, the fifth information is a cltm-Candidate information element. Optionally, the sixth information is an ltm-Candidate information element. Optionally, if the execution condition corresponding to the CLTM candidate cell is a Layer 1 condition, the fifth information element is included in the information element (such as neighborCellsMeasL1ListNR) used to record the Layer 1 measurement results of the neighboring cell. Optionally, if the execution condition corresponding to the CLTM candidate cell is a Layer 3 condition, the fifth information element is included in the information element (measResultNeighCells) used to record the Layer 3 measurement results of the neighboring cell. Optionally, the UE performs Operation 8 for one or more neighboring cells with available measurement results. Optionally, the UE performs the operation in operation 8 based on the execution condition to determine if it is a layer 1 condition for one or more neighboring cells with available layer 1 measurement results; alternatively, the UE performs the operation in operation 8 based on the execution condition to determine if it is a layer 3 condition for one or more neighboring cells with available layer 3 measurement results.

[0058] Operation 9: Optionally, for a neighboring cell, if it is a CLTM candidate cell and the execution condition corresponding to the CLTM candidate cell is a Layer 1 condition, then the value of the seventh information is set to indicate that it is a Layer 1 execution condition. Optionally, for a neighboring cell, if it is a CLTM candidate cell and the execution condition corresponding to the CLTM candidate cell is a Layer 3 condition, then the value of the seventh information is set to indicate that it is a Layer 3 execution condition. Optionally, this operation is performed for one or more neighboring cells. More specifically, it is performed for one or more neighboring cells with available measurement results. Optionally, this operation is performed on the target cell in the cell change process, in which case the neighboring cell in Operation 9 can be replaced by the target cell. Optionally, this operation is performed on one or more CLTM candidate cells stored by the UE.

[0059] Operation 10: Set the eighth information element to indicate that during the CLTM cell change process (such as when the T304 timer is running), the TAT of the early uplink synchronization TAT or pTAG corresponding to the target cell has timed out.

[0060] Operation 11: Set the ninth information element to indicate the remaining value of the early uplink synchronization TAT of the target cell or the initial value of the pTAG TAT when the CLTM cell change is initiated or when the CLTM target cell execution conditions are met; or to indicate whether the remaining value of the early uplink synchronization TAT of the target cell exceeds / is less than a configured threshold value when the CLTM cell change is initiated or when the CLTM target cell execution conditions are met.

[0061] Operation 12: Set the tenth information element to indicate the remaining value of the early uplink synchronization TAT or the running value of the pTAG TAT of the target cell when the CLTM cell change is successfully completed.

[0062] According to the above link reporting method, in a system that supports CLTM, when a UE configured with CLTM executes a successful CLTM process, if the process is not optimal or is a near failure process, the UE can trigger the recording of relevant cell change information during the CLTM process in the SHR, so that the network side can optimize the configuration and performance of subsequent CLTM based on the relevant information recorded by the UE.

[0063] This disclosure also proposes an implementation method for the CLTM procedure. In the current CLTM procedure, when all execution conditions (Layer 1 or Layer 3 conditions) corresponding to a CLTM candidate cell with an early uplink synchronization TAT in operation are met, the UE executes a cell change procedure to that candidate cell, designates it as the target primary cell, initiates the TAT of the Primary Timing Advance Group (pTAG) corresponding to that target cell, and executes a cell change procedure without random access. The initiation value of this TAT ​​applies the remaining value of the early uplink synchronization TAT of that cell. In this case, it is possible that the TAT of the pTAG or the early uplink synchronization TAT of the target cell will time out during CLTM execution (i.e., during T304 operation). In this case, due to uplink synchronization failure, the UE may not be able to successfully complete the cell change procedure. One implementation method is that if the pTAG or early uplink synchronization TAT corresponding to the target cell times out during T304 operation, the UE initiates a random access procedure to access that target cell. Optionally, if the UE determines that the first uplink transmission (via the resources of a Configured Grant (CG)) in the target cell has not yet been sent, it initiates a random access procedure to access the target cell. Alternatively, if the UE determines that the first uplink transmission in the target cell has been sent and no random access CLTM cell change has successfully concluded, it initiates a random access procedure to access the target cell. This implementation increases the probability of a successful cell change and shortens the time required to restore connection with the network.

[0064] In the above embodiments, unless otherwise specified, if the UE performs multiple operations in one step, the order of execution between the operations is not limited.

[0065] Figure 4 This is a block diagram illustrating a user equipment 40 according to an embodiment of the present disclosure. For example... Figure 4 As shown, the user equipment 40 includes a processor 401 and a memory 402. The processor 401 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 402 may include, for example, volatile memory (such as random access memory, RAM), a hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory. Program instructions are stored on the memory 402. When executed by the processor 401, these instructions can perform the methods described in detail in this disclosure within the user equipment.

[0066] A program running on a device according to this disclosure may be a program that enables a computer to perform the functions of embodiments of this disclosure by controlling a central processing unit (CPU). The program or the information processed by the program may be temporarily stored in volatile memory (such as random access memory RAM), hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems.

[0067] Programs used to implement the functions of the embodiments of this disclosure can be recorded on a computer-readable recording medium. The corresponding functions can be implemented by causing a computer system to read and execute the programs recorded on the recording medium. The term "computer system" here can refer to a computer system embedded in the device, and may include an operating system or hardware (such as peripheral devices). "Computer-readable recording medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-time dynamic storage program recording medium, or any other computer-readable recording medium.

[0068] Various features or functional modules of the devices used in the above embodiments can be implemented or executed by circuits (e.g., monolithic or multi-chip integrated circuits). Circuits designed to perform the functions described in this specification may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above devices. A general-purpose processor may be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The circuits described above may be digital circuits or analog circuits. In cases where advancements in semiconductor technology have led to new integrated circuit technologies that replace existing integrated circuits, one or more embodiments of this disclosure may also be implemented using these new integrated circuit technologies.

[0069] Furthermore, this disclosure is not limited to the embodiments described above. Although various examples of the embodiments have been described, this disclosure is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices, such as AV equipment, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0070] As described above, embodiments of this disclosure have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and this disclosure also includes any design modifications that do not depart from the spirit of this disclosure. Furthermore, various modifications can be made to this disclosure within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of this disclosure. In addition, components with the same effects described in the above embodiments can be substituted for each other.

Claims

1. A link reporting method, executed by a user equipment (UE), comprising: UEs configured with condition-based Layer 1 or Layer 2 triggered mobility CLTM or that have performed a CLTM procedure determine whether a link failure has occurred. and When a UE determines that a link failure has occurred, it stores link failure-related information in a UE variable used to store link failure information. This link failure-related information includes information related to the corresponding CLTM feature.

2. The link reporting method according to claim 1, wherein, Storing link failure information in the UE variables includes at least one of the following operations: The first information is set to indicate that the UE was in the uplink synchronization state with the target cell before the link failure occurred or before the CLTM cell change process was performed. The second information is set to indicate the time elapsed from the timeout of the early uplink synchronization time alignment timer TAT corresponding to the target cell to the execution of the failed CLTM cell change process or the fulfillment of the execution conditions corresponding to the failed CLTM cell change. The third piece of information is set to indicate the time elapsed from the start of the early uplink synchronization TAT corresponding to the target cell to the execution of the failed CLTM cell change process or the fulfillment of the execution conditions corresponding to the failed CLTM cell change. The value of the fourth information is set to indicate that the advance time (TA) value used in the CLTM cell change process is obtained through network signaling; If the last Radio Resource Control (RRC) reconfiguration message executed by the UE that included synchronization reconfiguration was about a CLTM cell change, set the value of the fifth information to indicate that the type of the last cell change executed by the UE was CLTM; If the UE has stored CLTM configuration information, the execution condition configuration corresponding to one or more CLTM candidate cells will be included in the Radio Link Failure (RLF) report.

3. The link reporting method according to claim 2, wherein, The first information is set when at least one of the following conditions is met: The link failure is a CLTM cell change failure. The CLTM cell change process is based on a random access procedure; The UE performed early uplink synchronization with the target cell before a link failure occurred or before the CLTM cell change process was executed.

4. A link reporting method, executed by a user equipment (UE), comprising: For UEs configured with condition-based Layer 1 or Layer 2 triggered mobility CLTM or that have performed a CLTM procedure, it is determined whether a successful handover or cell change procedure has been performed. and If the UE determines that a successful handover or cell change process has been performed, it will perform the operation of the Successful Handover Report (SHR) determination process. If the given conditions are met, the successful handover information or successful cell change information will be stored in the SHR variable.

5. The link reporting method according to claim 4, wherein, The given conditions include: The successful cell change performed was based on the CLTM procedure of random access; and Before the cell change process, the early uplink synchronization TAT corresponding to the target cell is in operation.

6. The link reporting method according to claim 4, wherein, The given conditions include: The successful cell change performed was a CLTM procedure without random access; and During the cell change process, the early uplink synchronization TAT corresponding to the target cell timed out.

7. The link reporting method according to claim 4, wherein, The given conditions include: The successful cell change performed is a CLTM process without random access; When the cell change process is triggered or executed, the early uplink synchronization TAT corresponding to the target cell is in a running state; and When the cell change process is triggered or executed, the running value of the early uplink synchronization TAT corresponding to the target cell exceeds the configured first threshold value, and the remaining value of the TAT is less than the configured second threshold value.

8. The link reporting method according to claim 4, wherein, During the SHR determination process, the UE performs at least one of the following operations: The first piece of information is set to indicate that the UE was in an uplink synchronization state with the target cell before performing the cell change process; The second piece of information is set to indicate the time elapsed from the early uplink synchronization TAT timeout corresponding to the target cell to the successful execution of the CLTM cell change process or the fulfillment of the execution conditions corresponding to the successful CLTM cell change. Set a third piece of information to indicate the time elapsed from the start of the early uplink synchronization TAT corresponding to the target cell to the successful execution of the CLTM cell change process or the fulfillment of the execution conditions corresponding to the successful CLTM cell change. In the event of a successful handover or cell change that is a CLTM cell change, a fourth piece of information is set to indicate that the handover or cell change is a CLTM cell change process. If the neighboring cell is a CLTM candidate cell, set the value of the fifth information to true to indicate that the neighboring cell is a CLTM candidate cell. If the neighboring cell is an LTM candidate cell, set the value of the sixth information to true to indicate that the neighboring cell is an LTM candidate cell. When a neighboring cell is a CLTM candidate cell and the execution condition corresponding to that CLTM candidate cell is a Layer 1 condition, the value of the seventh information is set to indicate that it is a Layer 1 execution condition. When a neighboring cell is a CLTM candidate cell and the execution condition corresponding to that CLTM candidate cell is a Layer 3 condition, the value of the seventh information is set to indicate that it is a Layer 3 execution condition.

9. The link reporting method according to claim 8, wherein, The first information is set when at least one of the following conditions is met: The successful cell change is a CLTM cell change; The CLTM cell change process is based on a random access procedure; Before executing the CLTM cell change process, the UE performed early uplink synchronization on the target cell.

10. A user equipment, comprising: processor; as well as Memory, which stores instructions The instructions execute the link reporting method according to any one of claims 1 to 9 when the processor is running.

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