Reason reporting method and device and storage medium

Abstract

The invention provides a reason reporting method and device and a storage medium, relates to the technical field of communication, and can solve the problem that a network does not define an optimization target of cell switching. The method comprises the following steps that: the terminal equipment executes LTM cell switching based on a random access channel (RACH) under the condition that the terminal equipment fails to execute the mobility LTM cell switching triggered by a layer one and a layer two of which the RACH-less is skipped; under the condition that the LTM cell switching based on the RACH is successful, a successful switching report is sent; wherein the successful switching report comprises a reason indication, and the reason indication is used for indicating a reason for executing successful LTM cell switching based on the RACH. According to the method and the device, the reason that the terminal equipment successfully executes the cell switching based on the RACH LTM can be reported to the network, so that the network can determine the optimization target of the cell switching.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a method, apparatus, and storage medium for reporting reasons. Background Art

[0002] During the LTM cell handover process, the network triggers the terminal device to perform a layer 1 (L1) / layer 2 (L2) triggered mobility (LTM) cell handover that skips the random access channel (RACH) by configuring early acquisition of the time advanced (TA) value based on the terminal's own measurement and / or early acquisition of the TA value based on the downlink control information. Among them, when the terminal device obtains a valid TA value of the target handover cell, it can successfully perform the LTM cell handover that skips the RACH; when it fails to obtain a valid TA value, it will fail to perform the LTM cell handover that skips the RACH, and will successfully perform the LTM cell handover based on the RACH.

[0003] In the scenario where the terminal fails to perform the LTM cell handover that skips the RACH and successfully performs the LTM cell handover based on the RACH, the network does not clarify the optimization goal of the cell handover. Consequently, it is impossible to optimize the cell handover process in a targeted manner, resulting in low reliability. Summary of the Invention

[0004] This application provides a method, apparatus, and storage medium for reporting reasons, which can report to the network the reasons why the terminal device fails to perform the LTM cell handover that skips the RACH and successfully performs the LTM cell handover based on the RACH, clarify the optimization goal of the cell handover, and thus facilitate the network to optimize the cell handover process in a targeted manner.

[0005] To achieve the above object, this application adopts the following technical solutions:

[0006] In a first aspect, this application provides a method for reporting reasons, which includes: when the LTM cell handover based on the RACH is successful, sending a successful handover report; where the successful handover report includes a reason indication for indicating the reason why the terminal device successfully performs the LTM cell handover based on the RACH.

[0007] In combination with the above first aspect, in a possible implementation, the method further includes: receiving successful handover report configuration information for indicating that the terminal device reports the reason indication when the LTM cell handover based on the RACH is successful.

[0008] Combined with the first aspect above, in a possible implementation, the method further includes: recording a cause indication in the successful handover report based on the successful handover report configuration information.

[0009] Combined with the first aspect above, in a possible implementation, the method further includes: sending indication information to the network, where the indication information is used to indicate that the terminal device stores a successful handover report.

[0010] Combined with the first aspect above, in a possible implementation, the cause indicated by the cause indication is any one of the following: the terminal device receives the configuration information for skipping RACH and successfully performs an RACH-based LTM cell handover; the terminal device does not receive the configuration information for skipping RACH and successfully performs an RACH-based LTM cell handover.

[0011] Combined with the first aspect above, in a possible implementation, the terminal device receives the configuration information for skipping RACH and successfully performs an RACH-based LTM cell handover, which is used to indicate any one of the following: the terminal device is configured to obtain a timing advance TA value based on the terminal device measurement and fails to obtain a valid TA value through the terminal device measurement; the terminal device is configured to obtain a TA value based on the downlink control information configured by the network and fails to obtain a valid TA value through the downlink control information configured by the network; the terminal device is configured to obtain a timing advance TA value based on the terminal device measurement and a TA value based on the downlink control information configured by the network and fails to obtain a valid TA value.

[0012] In a second aspect, the present application provides a cause reporting method, which includes: receiving a successful handover report; where the successful handover report includes a cause indication, and the cause indication is used to indicate the reason for the terminal device to successfully perform an RACH-based LTM cell handover.

[0013] Combined with the second aspect above, in a possible implementation, the method further includes: sending successful handover report configuration information; the successful handover report configuration information is used to indicate that the terminal device reports a cause indication when successfully performing an RACH-based LTM cell handover.

[0014] Combined with the second aspect above, in a possible implementation, the method further includes: receiving indication information; the indication information is used to indicate that the terminal device stores a successful handover report.

[0015] Combined with the second aspect above, in a possible implementation, the cause indicated by the cause indication is any one of the following: the terminal device receives the configuration information for skipping RACH and successfully performs an RACH-based LTM cell handover; the terminal device does not receive the configuration information for skipping RACH and successfully performs an RACH-based LTM cell handover.

[0016] Combined with the second aspect above, in a possible implementation, the terminal device receives the configuration information for skipping RACH and successfully performs an LTM cell handover based on RACH, which is used to indicate any of the following: the terminal device is configured to obtain the timing advance TA value based on the measurement of the terminal device, and an effective TA value is not obtained through the measurement of the terminal device; the terminal device is configured to obtain the TA value based on the downlink control information configured by the network, and an effective TA value is not obtained through the downlink control information configured by the network; the terminal device is configured to obtain the timing advance TA value based on the measurement of the terminal device and the TA value based on the downlink control information configured by the network, and an effective TA value is not obtained.

[0017] In a third aspect, the present application provides a cause reporting device, which includes: a communication unit; the communication unit is used to send a successful handover report when the LTM cell handover based on RACH is successful; wherein, the successful handover report includes a cause indication, and the cause indication is used to indicate the reason for the successful execution of the LTM cell handover based on RACH by the terminal device.

[0018] Combined with the third aspect above, in a possible implementation, the communication unit is further used to: receive the successful handover report configuration information; the successful handover report configuration information is used to indicate that the terminal device reports the cause indication when the LTM cell handover based on RACH is successful.

[0019] Combined with the third aspect above, in a possible implementation, the processing unit is further used to: record the cause indication in the successful handover report based on the successful handover report configuration information.

[0020] Combined with the third aspect above, in a possible implementation, the communication unit is further used to: send indication information to the network, and the indication information is used to indicate that the terminal device stores a successful handover report.

[0021] Combined with the third aspect above, in a possible implementation, the reason indicated by the cause indication is any of the following: the terminal device receives the configuration information for skipping RACH and successfully performs an LTM cell handover based on RACH; the terminal device does not receive the configuration information for skipping RACH and successfully performs an LTM cell handover based on RACH.

[0022] Combined with the above third aspect, in a possible implementation, the terminal device receives the configuration information for skipping RACH and successfully performs an LTM cell handover based on RACH, which is used to indicate any of the following: The terminal device is configured to obtain a timing advance (TA) value based on the measurement of the terminal device, and no valid TA value is obtained through the measurement of the terminal device; The terminal device is configured to obtain a TA value based on the downlink control information configured by the network, and no valid TA value is obtained through the downlink control information configured by the network; The terminal device is configured to obtain a TA value based on the measurement of the terminal device and a TA value based on the downlink control information configured by the network, and no valid TA value is obtained.

[0023] In a fourth aspect, the present application provides a cause reporting device, which includes: a communication unit; The communication unit is used to receive a handover success report; Wherein, the handover success report includes a cause indication, and the cause indication is used to indicate the reason for the terminal device to successfully perform an LTM cell handover based on RACH.

[0024] Combined with the above fourth aspect, in a possible implementation, the communication unit is further used to: send handover success report configuration information; The handover success report configuration information is used to indicate that the terminal device reports a cause indication when the LTM cell handover based on RACH is successfully performed.

[0025] Combined with the above fourth aspect, in a possible implementation, the communication unit is further used to: receive indication information; The indication information is used to indicate that the terminal device stores a handover success report.

[0026] Combined with the above fourth aspect, in a possible implementation, the cause indicated by the cause indication is any of the following: The terminal device receives the configuration information for skipping RACH and successfully performs an LTM cell handover based on RACH; The terminal device does not receive the configuration information for skipping RACH and successfully performs an LTM cell handover based on RACH.

[0027] Combined with the above fourth aspect, in a possible implementation, the terminal device receives the configuration information for skipping RACH and successfully performs an LTM cell handover based on RACH, which is used to indicate any of the following: The terminal device is configured to obtain a timing advance (TA) value based on the measurement of the terminal device, and no valid TA value is obtained through the measurement of the terminal device; The terminal device is configured to obtain a TA value based on the downlink control information configured by the network, and no valid TA value is obtained through the downlink control information configured by the network; The terminal device is configured to obtain a TA value based on the measurement of the terminal device and a TA value based on the downlink control information configured by the network, and no valid TA value is obtained.

[0028] Fifth aspect, the present application provides a cause reporting device, which includes: a processor and a communication interface; the communication interface is coupled to the processor, and the processor is configured to run a computer program or instruction to implement the cause reporting method described in the first aspect, any possible implementation manner of the first aspect, the second aspect, and any possible implementation manner of the second aspect.

[0029] Sixth aspect, the present application provides a computer-readable storage medium, in which instructions are stored. When the instructions run on a terminal, the terminal is caused to execute the cause reporting method described in the first aspect, any possible implementation manner of the first aspect, the second aspect, and any possible implementation manner of the second aspect.

[0030] Seventh aspect, the present application provides a computer program product containing instructions. When the computer program product runs on a computer, the computer is caused to execute the cause reporting method described in the first aspect, any possible implementation manner of the first aspect, the second aspect, and any possible implementation manner of the second aspect.

[0031] Eighth aspect, the present application provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor, and the processor is configured to run a computer program or instruction to implement the cause reporting method described in the first aspect, any possible implementation manner of the first aspect, the second aspect, and any possible implementation manner of the second aspect.

[0032] Specifically, the chip provided in the present application further includes a memory for storing a computer program or instruction.

[0033] It should be noted that the above computer instructions can be stored in whole or in part on a computer-readable storage medium. Among them, the computer-readable storage medium can be packaged together with the processor of the device or separately packaged from the processor of the device. The present application does not make any limitation in this regard.

[0034] Ninth aspect, the present application provides a communication system, which includes: a terminal device and a network. The terminal device is configured to execute the cause reporting method described in the first aspect and any possible implementation manner of the first aspect; the network is configured to execute the cause reporting method described in the second aspect and any possible implementation manner of the second aspect.

[0035] The descriptions of the second aspect to the ninth aspect in the present application can refer to the detailed description of the first aspect; and, for the beneficial effects of the descriptions of the second aspect to the ninth aspect, reference can be made to the analysis of the beneficial effects of the first aspect, which will not be elaborated here.

[0036] In this application, the name of the above-mentioned cause reporting device does not constitute a limitation on the device or functional module itself. In actual implementation, these devices or functional modules may appear under other names. As long as the functions of each device or functional module are similar to those of this application and fall within the scope of the claims of this application and their equivalent technologies.

[0037] These aspects or other aspects of this application will be made more concise and understandable in the following description.

[0038] The above solution at least brings the following beneficial effects: Based on the above technical solution, in the cause reporting method provided in this application, when the terminal device successfully switches to an LTM cell based on RACH, it sends a successful handover report. Among them, the successful handover report includes a cause indication for indicating the reason for the successful handover of the terminal device to the LTM cell based on RACH. That is to say, the above technical solution reports the cause indication through the successful handover report, so that the network can timely understand the reason for the successful execution of the LTM cell handover based on RACH, clarify the optimization target of the cell handover, and then facilitate the network to optimize the cell handover process targeted and improve the reliability of the cell handover. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of an LTM cell handover process provided by an embodiment of this application;

[0040] Figure 2 It is a schematic diagram of an RRC reconfiguration process provided by an embodiment of this application;

[0041] Figure 3 It is a schematic diagram of an RRC establishment process provided by an embodiment of this application;

[0042] Figure 4 It is a schematic diagram of an RRC reconstruction process provided by an embodiment of this application;

[0043] Figure 5 It is a schematic diagram of an RRC recovery process provided by an embodiment of this application;

[0044] Figure 6 It is a schematic diagram of the message reporting of the terminal information response provided by an embodiment of this application;

[0045] Figure 7 It is a schematic diagram of the architecture of a communication system provided by an embodiment of this application;

[0046] Figure 8 It is a schematic diagram of the hardware structure of a communication device provided by an embodiment of this application;

[0047] Figure 9 It is a flowchart of a cause reporting method provided by an embodiment of this application;

[0048] Figure 10 It is a flowchart of another cause reporting method provided by an embodiment of the present application;

[0049] Figure 11 It is a flowchart of another cause reporting method provided by an embodiment of the present application;

[0050] Figure 12 It is a flowchart of another cause reporting method provided by an embodiment of the present application;

[0051] Figure 13 It is a schematic structural diagram of a cause reporting device provided by an embodiment of the present application;

[0052] Figure 14 It is a schematic structural diagram of another cause reporting device provided by an embodiment of the present application. Detailed implementation manners

[0053] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0054] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone.

[0055] The terms "first" and "second" in the description and drawings of the present application are used to distinguish different objects or different treatments of the same object, rather than to describe the specific order of the object.

[0056] In addition, the terms "including" and "having" and any variations thereof mentioned in the description of the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include other unlisted steps or units, or may optionally further include other steps or units inherent to these processes, methods, products, or devices.

[0057] It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0058] In the description of the present application, unless otherwise specified, the meaning of "a plurality" refers to two or more.

[0059] Hereinafter, the nouns involved in the embodiments of the present application will be explained to facilitate the understanding of readers.

[0060] (1) LTM cell handover process.

[0061] In the 3rd generation partnership project (3GPP) Rel-19 phase, the LTM cell switch based on the new radio (NR) is introduced, which is applicable to the NR FR1 and FR2 networks.

[0062] Among them, LTM is a mobility management mechanism triggered based on the physical layer and the data link layer. In the LTM cell handover, the decision of the cell handover is based on the events triggered by L1 / L2. For example, during the movement of the terminal device, the physical layer monitors that the signal strength of the source cell is lower than a certain threshold, and at the same time the data link layer detects a decrease in the link quality. These L1 / L2-triggered events will trigger the network to start the cell handover process to find a suitable target cell.

[0063] Hereinafter, in combination with Figure 1 , the LTM cell handover process will be introduced.

[0064] Specifically, the LTM cell handover process mainly includes four processes: LTM preparation, early synchronization, LTM cell handover execution, and LTM cell handover completion. Among them, the process of LTM preparation includes the following steps 1-step 3; the process of early synchronization includes the following steps 4a-step 4b; the process of LTM cell handover execution includes the following steps 5-step 7; the process of LTM cell handover completion includes the following step 8.

[0065] Step 1: When the terminal device is in the radio resource control (RRC) connected state, it sends a measurement report to the access network device (which can also be understood as the network), and the access network device determines to configure LTM and starts the LTM candidate preparation.

[0066] Step 2: The access network device sends an RRC reconfiguration message to the terminal device. The RRC reconfiguration message includes the LTM candidate configuration.

[0067] Step 3: The terminal device stores the LTM candidate configuration and sends an RRC reconfiguration complete message to the access network device.

[0068] Step 4a: Before receiving the cell handover command, the terminal device performs downlink (DL) synchronization of the LTM candidate cell. When triggered by the access network device, the terminal device can activate / deactivate the transmission configuration indicator state (TCI state) of the candidate cell. The TCI state contains key configuration information related to downlink transmission, such as beam management, reference signal configuration, and quasi-colocation (QCL) relationship configuration. During the cell handover process, the reasonable management of the TCI state helps the terminal device accurately receive and decode signals from the candidate cell.

[0069] Step 4b: Before receiving the cell handover command, the terminal device performs uplink (UL) synchronization of the LTM candidate cell.

[0070] Specifically, the terminal device can use the TA value measurement method based on the terminal device (if the terminal device is configured with this method), and / or perform uplink synchronization by sending a preamble to the candidate cell (triggered by the access network device). When the TA value measurement method based on the terminal device is configured, the terminal device obtains the TA value of the candidate cell through measurement. Before receiving the cell handover command, the terminal device performs early TA value acquisition of the candidate cell upon network request. Through contention free random access (CFRA) triggered by the source cell sending downlink control information (PDCCH order), the terminal device sends a preamble to the indicated candidate cell. To minimize the data interruption of the source cell introduced by the contention free random access of the candidate cell, the terminal device does not receive the random access response of the candidate cell (because receiving the random access response may take a certain amount of time, during which the terminal device may not be able to normally receive data from the source cell, resulting in data interruption. By not receiving the random access response, the terminal device can quickly return to the communication state of the source cell, reducing the time and impact of data interruption). The TA value of the candidate cell is indicated to the terminal device through the cell handover command. The terminal device also does not maintain a TA timer for the candidate cell, but relies on the network to ensure the validity of the TA value.

[0071] Step 5: The terminal device performs L1 measurement on the configured LTM candidate cell and sends an L1 measurement report to the access network device to trigger the access network device to perform an LTM decision. Among them, as long as the terminal device uses the RRC configuration (i.e., Step 2), it should perform L1 measurement.

[0072] Step 6: The access network device determines to perform a cell handover to the target cell (the target cell is one of the candidate cells). For example, the cell handover is triggered by sending an LTM cell handover command (MAC CE). The cell handover command includes a target configuration identifier indicating the candidate configuration of the target cell. The terminal device switches to the target cell, disconnects from the source cell, and uses the candidate configuration indicated by the target configuration identifier.

[0073] Step 7: If the terminal device fails to obtain a valid TA value for the target cell, indicating that the LTM cell handover that skips RACH fails, then the terminal device performs an LTM cell handover process based on RACH to the target cell.

[0074] Step 8: The terminal device sends an RRC reconfiguration complete message to the target cell to complete the LTM cell handover process.

[0075] Among them, if the terminal device performs an LTM cell handover process based on RACH in Step 7, when the random access process is completed, the terminal device determines that the LTM cell handover is successfully completed. For the LTM (RACH-less LTM) cell handover that skips RACH, when the terminal device determines that the network has successfully received its first uplink data, the terminal device determines that the LTM cell handover is successfully completed.

[0076] Considering that the logical channel priority of the signaling radio bearer 1 (SRB1) where the RRC reconfiguration complete message is located is relatively high, the terminal device will preferentially complete the MAC packetization of the RRC reconfiguration complete message during the LTM cell handover that skips RACH and send it to the target cell as the first uplink data after LTM switches to the target cell (the new cell).

[0077] Optionally, in the continuous execution of LTM cell handover, Steps 4 to 8 can be executed multiple times using the LTM candidate configuration.

[0078] (2) The process for the terminal device to enable the network to obtain a successful handover report (SHR) after the handover is successful.

[0079] 1. To analyze sub-optimal successful handover events, the network configures a SuccessHO-Config for successful handover reporting to the UE via an RRC reconfiguration message, such that when the conditions set in the successful handover reporting configuration are met, the terminal device provides a successful handover report to the network.

[0080] 2. If the preset configuration information in the successful handover reporting configuration is satisfied, the terminal device records the information of the successful handover in the varSuccessHO-Config. Furthermore, the content in the varSuccessHO-Config is set (for example, information such as the cause value of the successful handover is set).

[0081] Among them, the preset configuration information may include at least one of the following: meeting the T304 threshold ratio, T301 threshold ratio, T312 threshold ratio, or the existence of a source dual active protocol stack (DAPS) failure report.

[0082] 3. For the analysis of successful handovers, the terminal device collects successful handover reports according to the network configuration. If a successful handover report is stored, it makes the successful handover report available to the network as specified in TS 38.331. The terminal stores the successful handover report until the network obtains it, otherwise it discards it after a preset duration for obtaining the successful handover report (for example, 48 hours).

[0083] Optionally, the implementation process for the terminal device to make the successful handover report available to the network can be: the terminal device indicates the availability of the successful handover report (successHO-InfoAvailable) in the RRC message sent to the network (such as the access network device).

[0084] Among them, the RRC message can be at least one of the following: RRC reconfiguration complete message, RRC setup complete message, RRC reestablishment complete message, or RRC resume complete message.

[0085] Among them, for the process of the terminal device sending an RRC reconfiguration complete message to the network, as Figure 2 shown, the network sends an RRC reconfiguration indication to the terminal device. The terminal device sends an RRC reconfiguration complete message to the network.

[0086] For the implementation process of the terminal device sending an RRC setup complete message to the network, asFigure 3 As shown, the terminal device sends an RRC setup request to the network; the network sends an RRC setup indication to the terminal device; the terminal device sends an RRC setup complete message to the network.

[0087] Regarding the implementation process of the terminal device sending an RRC reestablishment complete message to the network, as Figure 4 shown, the terminal device sends an RRC reestablishment request to the network; the network sends an RRC reestablishment indication to the terminal device; the terminal device sends an RRC reestablishment complete message to the network.

[0088] Regarding the implementation process of the terminal device sending an RRC resume complete message to the network, as Figure 5 shown, the terminal device sends an RRC resume request or an RRC resume request 1 to the network; the network sends an RRC resume indication to the terminal device; the terminal device sends an RRC resume complete message to the network.

[0089] 4. As Figure 6 shown, the network sends UE information request information to the terminal device. The UE information request information includes a success HO-ReportReq, which is used to instruct the terminal device to report a successful handover report.

[0090] 5. When the terminal device meets the preset conditions, it sets the successful handover report in the UE information response message to the value of the successful handover report in the varSuccessHO-Config. Among them, the value of the successful handover report in the varSuccessHO-Config can be understood as the successful handover report stored by the terminal device.

[0091] Optionally, the preset conditions may be: the handover report request information in the terminal device is set to the first identifier (e.g., true); and, there is available successful handover information in the terminal device. And, the registered public land mobile network (RPLMN) is included in the network identifier list (plmn-IdentityList) of the registered public land mobile networks stored in the variable successful handover report (that is, the registered public land mobile network must be included in the network identifier list in the variable successful handover report, which means that there is a matching relationship between the currently registered public land mobile network and the network identifier list in the previously stored handover-related information).

[0092] Optionally, the preset conditions may also be: the handover report request information in the terminal device is set to the first identifier (e.g., true); and, there is available successful handover information in the terminal device; and, the currently registered stand-alone non-public network (SNPN) identity is included in the network identifier list (plmn-IdentityList) stored in the variable successful handover report.

[0093] Optionally, the preset conditions may also be: the successful handover report in the variable successful handover report involves the dual active protocol stack (DAPS), and non-duplicate packet data convergence protocol (PDCP) data units (PDUs) have been received from the target cell of the relevant handover.

[0094] In a possible implementation, if the successful handover report in the variable successful handover report involves the dual active protocol stack (DAPS), and non-duplicate packet data convergence protocol (PDCP) data units (PDUs) have been received from the target cell of the relevant handover, the terminal device sets the value of setUpInterruptionTimeAtHO in the variable successful handover report to include the time difference between the time when the last PDCP PDU is received from the source cell of the relevant handover and the time when the first non-duplicate PDCP PDU is received from the target cell of the relevant handover. For example, the arrival time measured when the first non-duplicate PDCP PDU is received in the target cell.

[0095] Herein, this value is a time difference, and the specific calculation method is the difference between the time when the last PDCP PDU is received from the source cell of the relevant handover and the time when the first non-duplicate PDCP PDU is received from the target cell of the relevant handover. And this time difference is determined according to the arrival time measured when the first non-duplicate PDCP PDU is received from the target cell.

[0096] Optionally, the preset condition can also be: the successful handover report in the variable handover success report involves the identifier of the mobility controlled by the New Radio command (mobilityFromNRCommand).

[0097] In a possible implementation, if the successful handover report in the variable handover success report involves the identifier of the mobility controlled by the New Radio command (mobilityFromNRCommand), the time identifier (timeSinceSHR) in the variable successful handover report is set to the time since the successful handover report is determined.

[0098] Herein, the mobilityFromNRCommand identifier can indicate that this successful handover report is associated with the mobility command sent from the New Radio.

[0099] Optionally, the preset condition can also be: the terminal device has an available successful handover report.

[0100] In a possible implementation, if the terminal device has an available successful handover report, the successful handover report in the terminal information response message is set to the value of the successful handover report in the variable successful handover report (varSuccessHO-Config).

[0101] 6. As Figure 6 shown, the terminal device sends a terminal information response message to the network.

[0102] Furthermore, after the terminal device confirms the successful transmission of the terminal information response message, it discards the variable successful handover report.

[0103] Above, the nouns and communications involved in the embodiments of the present application have been specifically introduced.

[0104] The terminal device depends on a valid TA value to perform an LTM cell handover that skips RACH. That is, when the terminal device obtains a valid TA value of the handover cell, it can successfully perform an LTM cell handover that skips RACH; when it does not obtain a valid TA value, it will fail to perform an LTM cell handover that skips RACH and instead perform an LTM cell handover based on RACH.

[0105] Moreover, when a valid TA value is provided in the cell handover command sent by the network, the terminal device uses the valid TA value carried in the command. When measurements based on the TA value of the terminal device are configured but no valid TA value is provided in the cell handover command sent by the network, if the terminal device measures a valid TA value, the terminal device uses the measured TA value. When a valid TA value is provided in the cell handover command sent by the network and the terminal device measures a valid TA value, the terminal device first follows the valid TA value provided in the cell handover command.

[0106] In addition, when receiving a cell handover command, the terminal device performs an LTM cell handover that skips the RACH. If the terminal device does not have a valid TA value, it performs an LTM cell handover based on the RACH.

[0107] It should be noted that regardless of whether the terminal device is configured to measure the TA value (UE-based TA) of a specific candidate cell, the terminal device needs to follow the downlink control information that includes a request to perform a random access procedure for the candidate cell. Similarly, for candidate cells for which the terminal device can derive the TA value itself, the terminal device also needs to follow the downlink control information that includes a request to perform a random access procedure for the candidate cell. In addition, regardless of whether the terminal device has already performed a random access procedure for the candidate cell, if the terminal device is configured with a measurement configuration based on the terminal device, the terminal device will perform a measurement based on the terminal device.

[0108] Successful cell handover includes successful LTM cell handover that skips the RACH or successful LTM cell handover based on the RACH.

[0109] Among them, the network triggers the terminal device to perform an LTM cell handover that skips the RACH by configuring early acquisition of the TA value based on the terminal's own measurement and / or early acquisition of the TA value based on the downlink control information. In the following two cases, the terminal device will experience a failure in performing an LTM cell handover that skips the RACH and a successful LTM cell handover based on the RACH.

[0110] Case 1: The network only configures the early acquisition method of the TA value based on the terminal's own measurement; moreover, the terminal device does not obtain a valid TA value based on this method.

[0111] Case 2: The network configures the early acquisition method of the TA value based on the downlink control information; moreover, the terminal device does not obtain a valid TA value based on this method. And in this case, the network does not configure the early acquisition method of the TA value based on the terminal's own measurement; or the network configures the early acquisition method of the TA value based on the terminal's own measurement; moreover, the terminal device does not obtain a valid TA value based on this method.

[0112] In summary, during the LTM cell handover process, the network triggers the terminal device to perform an LTM cell handover that skips the RACH by configuring early acquisition of TA values based on the terminal's own measurements and / or early acquisition of TA values based on downlink control information. Among them, when the terminal device obtains the TA value of the effective handover cell, it can successfully perform an LTM cell handover that skips the RACH; when it fails to obtain the effective TA value, it will fail to perform an LTM cell handover that skips the RACH, and successfully perform an LTM cell handover based on the RACH.

[0113] In the scenario where the terminal fails to perform an LTM cell handover that skips the RACH and successfully performs an LTM cell handover based on the RACH, the network is not clear about the optimization goal of the cell handover, that is, the network does not know the reason why the terminal device fails to perform an LTM cell handover that skips the RACH and successfully performs an LTM cell handover based on the RACH. Moreover, the network is also unclear about the usage of the signaling it configures, and thus cannot optimize the cell handover process targeted, resulting in low reliability.

[0114] In view of this, in the cause reporting method provided in this application, when the terminal device successfully performs an LTM cell handover based on the RACH, it sends a successful handover report. Among them, the successful handover report includes a cause indication for indicating the reason why the terminal device successfully performs an LTM cell handover based on the RACH. That is to say, the above technical solution reports the cause indication through the successful handover report, so that the network can timely understand the reason for the successful implementation of the LTM cell handover based on the RACH, clarify the optimization goal of the cell handover, and then facilitate the network to optimize the cell handover process targeted and improve the reliability of the cell handover.

[0115] Next, the implementation manners of the embodiments of this application will be described in detail with reference to the accompanying drawings of the specification.

[0116] Figure 7 It is a schematic diagram of the architecture of a communication system provided by an embodiment of this application. As Figure 7 shown, the communication system includes: a terminal device 701 and a network 702.

[0117] Among them, the number of terminal devices 701 can be one or multiple. For the sake of understanding, Figure 7 only one is shown. The terminal device 701 and the network 702 are connected through a communication link. The communication link can be a wired communication link or a wireless communication link, and this application does not make a limitation on this.

[0118] Next, the terminal device 701 in the embodiments of this application will be introduced.

[0119] In a possible implementation, the terminal device 701 is used to perform an LTM cell handover based on RACH. Further, when the LTM cell handover based on RACH is successfully performed, the terminal device 701 sends a successful handover report to the network 702. The successful handover report includes the reason for the successful LTM cell handover based on RACH performed by the terminal device 701.

[0120] Optionally, the terminal device 701 is further used to record the reason for the successful LTM cell handover based on RACH in the successful handover report.

[0121] Optionally, the terminal device 701 in the embodiments of the present application may also be an entity on the user side for receiving signals, or sending signals, or receiving and sending signals. The terminal device 701 is used to provide one or more of voice services and data connectivity services to the user. The terminal device 701 may also be referred to as a user equipment (UE), a terminal, an access terminal, a user unit, a user station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user device. The terminal device 701 may be a vehicle-to-everything (V2X) device, for example, a smart car (smart car or intelligent car), a digital car, a driverless car (unmanned car or driverless car or pilotless car or automobile), a self-driving car (self-driving car or autonomous car), a pure electric vehicle (pure EV or Battery EV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), a new energy vehicle, etc. The terminal device 701 may also be a device-to-device (D2D) device, for example, a power meter, a water meter, etc.

[0122] The terminal device 701 may also be a mobile station (MS), a subscriber unit, a drone, an Internet of Things (IoT) device, a station (ST) in a WLAN, a cellular phone, a smart phone, a cordless phone, a wireless data card, a tablet computer, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA) device, a laptop computer, a Machine Type Communication (MTC) terminal, a handheld device with wireless communication capabilities, a computing device, or other processing devices connected to a wireless modem, a vehicle-mounted device, a wearable device (which may also be referred to as a wearable intelligent device). The terminal device 701 may also be a terminal device in a next-generation communication system, for example, a terminal device in a 5G system or a terminal device in a future evolved PLMN, a terminal device in an NR system, etc.

[0123] Next, the network 702 in the embodiments of the present application will be introduced.

[0124] In a possible implementation, the network 702 is used to receive a successful handover report.

[0125] Furthermore, the network 702 may optimize the cell handover process based on the reason for the successful RACH-based LTM cell handover of the terminal device 701 included in the successful handover report to improve the reliability of cell handover.

[0126] Optionally, the network 702 in the embodiments of the present application is an entity on the network side for sending signals, or receiving signals, or sending and receiving signals. The network 702 may be a device deployed in a radio access network (RAN) to provide wireless communication functions for terminal devices. For example, it may be a TRP, a base station (such as an evolved NodeB (eNB or eNodeB), a next-generation base station node (gNB), a next-generation eNB (ng-eNB), etc.), various forms of control nodes (such as a network controller, a radio controller (such as a radio controller in a cloud radio access network (CRAN) scenario)), a road side unit (RSU), etc.). Specifically, the network 702 may be various forms of macro base stations, micro base stations (also known as small stations), relay stations, access points (APs), etc., or an antenna panel of a base station. The control node may be connected to multiple base stations and configure resources for multiple terminal devices covered by the multiple base stations. In systems using different radio access technologies (RATs), the names of devices with base station functions may be different. For example, in an LTE system, it may be called an eNB or eNodeB, and in a 5G system or an NR system, it may be called a gNB. The present application does not limit the specific name of the network 702.

[0127] When implemented through hardware, each module in the communication system can be integrated and implemented on the hardware structure of a communication device as Figure 8 shown. Specifically, as Figure 8 shown, the basic hardware structure of the communication device is introduced.

[0128] Figure 8 It is a schematic diagram of the hardware structure of a communication device provided by an embodiment of the present application. As Figure 8 shown, the communication device includes at least one processor 801, a communication line 802, and at least one communication interface 804, and may further include a memory 803. Among them, the processor 801, the memory 803, and the communication interface 804 can be connected through the communication line 802.

[0129] The processor 801 can be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application. For example, one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs).

[0130] The communication line 802 may include a path for transmitting information between the above components.

[0131] The communication interface 804, for communicating with other devices or communication networks, can use any transceiver-like device, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0132] The memory 803 can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to include or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto.

[0133] In a possible design, the memory 803 can exist independently of the processor 801, that is, the memory 803 can be an external memory of the processor 801. At this time, the memory 803 can be connected to the processor 801 through the communication line 802, used to store execution instructions or application program codes, and controlled by the processor 801 to execute, so as to implement the cause reporting method provided in the following embodiments of the present application. In another possible design, the memory 803 can also be integrated with the processor 801, that is, the memory 803 can be an internal memory of the processor 801. For example, the memory 803 is a cache, which can be used to temporarily store some data and instruction information, etc.

[0134] As a possible implementation manner, the processor 801 can include one or more CPUs, such as Figure 8 CPU0 and CPU1 in Figure 8 . As another possible implementation manner, the communication device can include multiple processors, such as

[0135] the processor 801 and the processor 807 in

[0136] Figure 9 . As yet another possible implementation manner, the communication device can further include an output device 805 and an input device 806. Figure 7 As Figure 9 shown, the method includes the following S901 - S902.

[0137] S901. The terminal device performs an LTM cell handover based on RACH.

[0138] In a possible implementation manner, when the terminal device receives the configuration information for skipping RACH (that is, the terminal device is configured with the function of skipping RACH), the terminal device performs an LTM cell handover that skips RACH based on the TA value of the target cell; and, when the LTM cell handover that skips RACH fails, the terminal device performs an LTM cell handover based on RACH.

[0139] Or, in another possible implementation manner, when the terminal device does not receive the configuration information for skipping RACH (that is, the terminal device is not configured with the function of skipping RACH), the terminal device performs an LTM cell handover based on RACH.

[0140] Optionally, for the terminal device, the process of performing a failed LTM cell handover that skips the RACH specifically includes: when the downlink control information configured by the network does not provide a valid TA value, if there is no configuration for the terminal device to measure the TA value, or when there is a configuration for the terminal device to measure the TA value, and the terminal device fails to obtain a valid TA value through its own measurement, the terminal device performs a failed LTM cell handover that skips the RACH.

[0141] Optionally, a failed LTM cell handover that skips the RACH can be represented as the LTM cell handover that skips the RACH not being performed; or based on the early acquisition of the TA value for RACH-less, a valid TA value is not obtained.

[0142] S902. In the case of a successful LTM cell handover based on the RACH, the terminal device sends a successful handover report. Correspondingly, the network receives the handover success report.

[0143] Among them, the successful handover report includes a cause indication, and the cause indication is used to indicate the reason for the terminal device to perform a successful LTM cell handover based on the RACH.

[0144] In some embodiments, the reason indicated by the cause indication is any one of the following 01 - 02:

[0145] 01. The terminal device receives the configuration information for skipping the RACH and performs a successful LTM cell handover based on the RACH.

[0146] It should be noted that when the terminal device receives the configuration information for skipping the RACH, it means that the terminal device is configured with the function of skipping the RACH. That is to say, when the terminal device performs an LTM cell handover, the terminal device has the ability to perform an LTM cell handover that skips the RACH. However, the terminal device performs a successful LTM cell handover based on the RACH, indicating that when the terminal device performs an LTM cell handover that skips the RACH, there is a problem of a failed LTM cell handover that skips the RACH, and then it performs an LTM cell handover based on the RACH.

[0147] Furthermore, it can be understood that the reason for the terminal to perform a successful LTM cell handover based on the RACH can be that the terminal device fails to perform an LTM cell handover that skips the RACH.

[0148] 02. The terminal device does not receive the configuration information for skipping the RACH and performs a successful LTM cell handover based on the RACH.

[0149] It should be noted that the terminal device does not receive the configuration information for skipping the RACH, which means that the function of skipping the RACH is not configured for the terminal device. That is to say, when the terminal device performs an LTM cell handover, the terminal device does not have the ability to perform an LTM cell handover by skipping the RACH, but only has the ability to successfully perform an LTM cell handover based on the RACH.

[0150] Furthermore, it can be understood that the reason for the terminal to successfully perform an LTM cell handover based on the RACH can also be that the terminal device is not configured with the ability to perform an LTM cell handover by skipping the RACH.

[0151] Among them, optionally, 01. The terminal device receives the configuration information for skipping the RACH and successfully performs an LTM cell handover based on the RACH, which is used to indicate any one of the following items 11-13:

[0152] 11. The terminal device is configured to obtain the TA value based on the TA value measured by the terminal device, and no valid TA value is obtained through the method of measuring by the terminal device.

[0153] It can be understood that if the configuration information for skipping the RACH received by the terminal device includes "obtaining the TA value based on the TA value measured by the terminal device", then the terminal will be configured with "obtaining the TA value based on the TA value measured by the terminal device". That is to say, when the terminal device performs an LTM cell handover by skipping the RACH, the terminal device can obtain the TA value based on the method of measuring by the terminal device. Furthermore, it shows that the reason for the terminal to successfully perform an LTM cell handover based on the RACH (the LTM cell handover by skipping the RACH fails) is that no valid TA value is obtained through the method of measuring by the terminal device.

[0154] 12. The terminal device is configured to obtain the TA value based on the downlink control information configured by the network, and no valid TA value is obtained through the downlink control information configured by the network.

[0155] It can be understood that if the configuration information for skipping the RACH received by the terminal device includes "obtaining the TA value based on the downlink control information configured by the network", then the terminal will be configured with "obtaining the TA value based on the downlink control information configured by the network". That is to say, when the terminal device performs an LTM cell handover by skipping the RACH, the terminal device can obtain the TA value based on the downlink control information configured by the network. Furthermore, it shows that the reason for the terminal to successfully perform an LTM cell handover based on the RACH (the LTM cell handover by skipping the RACH fails) is that no valid TA value is obtained through the downlink control information configured by the network.

[0156] 13. The terminal device is configured to obtain the timing advance TA value based on the measurement of the terminal device and obtain the TA value based on the downlink control information configured by the network, and no valid TA value is obtained.

[0157] It is understandable that if the configuration information for skipping the RACH received by the terminal device includes "obtaining the TA value based on the TA value measured by the terminal device" and "obtaining the TA value based on the TA value of the downlink control information configured by the network", the terminal will be configured with "obtaining the TA value based on the TA value measured by the terminal device" and "obtaining the TA value based on the TA value of the downlink control information configured by the network". That is to say, when the terminal device performs an LTM cell handover with RACH skipped, the terminal device can obtain the TA value based on the method of measurement by the terminal device and / or the method of the downlink control information configured by the network. Furthermore, it shows that the reason for the successful execution of the LTM cell handover based on RACH (the failure of the LTM cell handover with RACH skipped) is that no valid TA value is obtained through the method of measurement by the terminal device and / or the downlink control information configured by the network (that is, the terminal device does not obtain a valid TA value).

[0158] The following describes the specific indication methods for "not obtaining a valid Timing Advance TA value through the method of measurement by the terminal device", "not obtaining a valid TA value through the downlink control information configured by the network", and "not obtaining a valid TA value" in the cause indication.

[0159] Optionally, the cause indication can be an explicit cause indication or an implicit cause indication.

[0160] In one possible implementation manner, corresponding to the cause indication being an explicit cause indication, the cause indicated by the explicit cause indication is "the reason for the failure of the LTM cell handover with RACH skipped is that no valid TA value is obtained" (that is, the RACH-less TA acquisition is invalid).

[0161] Among them, the explicit cause indication can be an enumerated type, including a first identifier (for example, true), used to indicate that the cause indication is true. Or, the cause indication can also be of byte type (for example, 1-bit byte, where 1 represents true and 0 represents false).

[0162] In another possible implementation manner, corresponding to the cause indication being an implicit cause indication, the cause indicated by the implicit cause indication is "not obtaining a valid Timing Advance TA value through the method of measurement by the terminal device" (that is, UE measurement based invalid TA), or "not obtaining a valid TA value through the downlink control information configured by the network" (that is, PDCCH order based invalid TA).

[0163] Among them, "failing to obtain a valid TA value through the downlink control information configured by the network" is used to indicate that the network has configured the downlink control information, but fails to obtain a valid TA value through the downlink control information configured by the network, and the early acquisition of the TA value measured by the terminal device (UE measurement based TA) has not been configured, or the early acquisition of the TA value measured by the terminal device has been configured, but a valid TA value has not been measured.

[0164] Among them, the implicit cause indication can be represented by 1 byte. For example, 1 represents "failing to obtain a valid timing advance TA value through the measurement of the terminal device"; 0 represents "failing to obtain a valid TA value through the downlink control information configured by the network".

[0165] The implicit cause indication can also be comprehensively represented in the form of 2 bytes. For example, 01 represents "failing to obtain a valid timing advance TA value through the measurement of the terminal device"; 10 represents "failing to obtain a valid TA value through the downlink control information configured by the network".

[0166] The implicit cause indication can also be comprehensively represented in the form of an enumeration type, a list type (list), or a bitmap image (bitmap).

[0167] In a possible implementation manner, the implementation process of S902 refers to the embodiments shown in S1101 - S1103, which will not be elaborated here.

[0168] Based on the above technical solution, for the cause reporting method provided in this application, when the terminal device successfully switches to an LTM cell based on RACH, it sends a successful handover report. Among them, the successful handover report includes a cause indication for indicating the reason for the successful handover of the terminal device to the LTM cell based on RACH. That is to say, the above technical solution reports the cause indication through the successful handover report, so that the network can timely understand the reason for the successful handover of the LTM cell based on RACH, clarify the optimization target of the cell handover, and then facilitate the network to optimize the cell handover process targeted and improve the reliability of the cell handover.

[0169] As a possible embodiment of this application, in combination with Figure 9 , as Figure 10 shown, before the above S901, the process of configuring the successful handover report for the terminal device can be implemented through the following S1001.

[0170] S1001: The network sends the successful handover report configuration information. Correspondingly, the terminal device receives the successful handover report configuration information.

[0171] Among them, the successful handover report configuration information is used to indicate that when the terminal device fails to perform the LTM cell handover skipping the RACH and then successfully performs the LTM cell handover based on the RACH, it reports the cause indication. Alternatively, the configuration information of this successful handover report is also used to configure the indication method of the cause indication. For example, it indicates that the cause indication is an explicit cause indication or an implicit cause indication.

[0172] Among them, optionally, the configuration information of this successful handover report can be explicit configuration information or implicit configuration information. The explicit configuration information or implicit configuration information is information that may or may not exist.

[0173] In a possible implementation manner, corresponding to the configuration information of the successful handover report being explicit configuration information, the explicit configuration information can be "report the cause indication when the LTM cell handover skipping the RACH fails and / or the LTM cell handover based on the RACH is successful".

[0174] Among them, the explicit configuration information can be of an enumerated type, including a first identifier (for example, true), used to identify that the explicit configuration information is true. Alternatively, the explicit configuration information can also be of a byte type (for example, a 1-bit byte, where 1 represents true and 0 represents false).

[0175] In another possible implementation manner, corresponding to the configuration information of the successful handover report being implicit configuration information, the implicit configuration information can be "no valid timing advance TA value is obtained through the measurement method of the terminal device" (that is, UE measurement based invalid TA), or "no valid TA value is obtained through the downlink control information configured by the network" (that is, PDCCH order based invalid TA).

[0176] It should be noted that "no valid timing advance TA value is obtained through the measurement method of the terminal device" is specifically used to characterize that when no valid timing advance TA value is obtained through the measurement method of the terminal device, it will cause the terminal device to fail to perform the LTM cell handover skipping the RACH. That is to say, by "no valid timing advance TA value is obtained through the measurement method of the terminal device" to indicate that the terminal device reports the cause indication when no valid timing advance TA value is obtained through the measurement method of the terminal device, it is equivalent to indicating that the terminal device reports the cause indication when the LTM cell handover skipping the RACH fails.

[0177] Similarly, by "obtaining a valid TA value through the downlink control information not configured by the network", it is indicated that the terminal device reports a cause indication when obtaining a valid TA value through the downlink control information not configured by the network, which is equivalent to indicating that the terminal device reports a cause indication when the LTM cell handover that skips the RACH fails.

[0178] Among them, "obtaining a valid TA value through the downlink control information not configured by the network" is used to indicate that the network configures the downlink control information, but fails to obtain a valid TA value through the downlink control information configured by the network, and does not configure the early acquisition of the TA value measured by the terminal device (UE measurement based TA), or configures the early acquisition of the TA value measured by the terminal device, but fails to measure a valid TA value.

[0179] Among them, the implicit configuration information can be represented by 2 byte bits. For example, 1 represents "obtaining a valid timing advance TA value through the method of measurement by the terminal device"; 0 represents "obtaining a valid TA value through the downlink control information not configured by the network".

[0180] The implicit configuration information can also be comprehensively represented in the form of 2 byte bits. For example, 01 represents "obtaining a valid timing advance TA value through the method of measurement by the terminal device"; 10 represents "obtaining a valid TA value through the downlink control information not configured by the network".

[0181] The implicit configuration information can also be comprehensively represented in the form of an enumeration type, a list type (list), or a bitmap image (bitmap).

[0182] In some embodiments, the network can send the successful handover report configuration information to the terminal device in a transparent transmission manner. Alternatively, the network can also send the successful handover report configuration information to the terminal device in a relay transmission manner. Alternatively, the network can also send the successful handover report configuration information to the terminal device in an encrypted transmission manner.

[0183] Of course, the above is only an exemplary description of transmitting the successful handover report configuration information. The implementation process of the above transmitting the successful handover report configuration information can also be implemented by other transmission methods in the future, and the embodiments of the present application do not make any restrictions on this.

[0184] Further, optionally, S1001 is an optional step, that is, S1001 can be executed or not executed.

[0185] In some embodiments, for the solution of executing S1001, the terminal device records a cause indication in the successful handover report based on the successful handover report configuration information.

[0186] Exemplarily, when the terminal device receives the successful handover report configuration information, if the successful handover report configuration information is satisfied, a cause indication is recorded in the successful handover report.

[0187] For example, the implementation process of the terminal device recording the cause indication in the successful handover report may include: the terminal device records the cause indication in the variable successful handover report (varSuccessHO-Config). Furthermore, the content in the variable successful handover report is set (for example, information such as the cause value of the successful handover is set).

[0188] In some other embodiments, for the solution that does not execute S1001, when the terminal device does not receive the successful handover report configuration information, if the preset configuration information is satisfied and the condition that after the LTM cell handover failure of skipping RACH is executed and the LTM cell handover based on RACH is successful is satisfied, a cause indication is recorded in the successful handover report.

[0189] Optionally, the preset configuration information includes at least one of the following: meeting the T304 threshold ratio, T301 threshold ratio, T312 threshold ratio, or the existence of a DAPS failure report.

[0190] Based on the above technical solution, the terminal device receives the successful handover report configuration information so that the terminal device can report the cause indication based on this configuration information.

[0191] As a possible embodiment in the present application, in combination with Figure 9 , as Figure 11 shown, the implementation process of the terminal device sending the successful handover report in S902 above may include the following S1101 - S1103.

[0192] S1101. The terminal device sends indication information to the network. Correspondingly, the network receives the indication information.

[0193] Among them, the indication information is used to indicate that the terminal device stores a successful handover report, or indicates that the successful handover report is in an available state (successHO-InfoAvailable) for the network.

[0194] Optionally, the indication information may be carried in an RRC message sent by the terminal device to the network. For example, the RRC message may be at least one of the following: RRC reconfiguration complete message, RRC setup complete message, RRC reestablishment complete message, or RRC resume complete message.

[0195] In a possible implementation manner, the specific implementation process for the terminal device to send indication information to the network may refer to step 3 in the "process for the terminal device to enable the network to obtain a successful handover report (SHR) after a successful handover" in the above-mentioned glossary section, which will not be elaborated here.

[0196] S1102. The network sends a terminal information request to the terminal device. Correspondingly, the terminal device receives the terminal information request.

[0197] Among them, the terminal information request includes a success handover report request (successHO-ReportReq). This success handover report request (successHO-ReportReq) is used to instruct the terminal device to report a successful handover report.

[0198] In a possible implementation manner, the implementation process of S1102 may refer to step 4 in the "process for the terminal device to enable the network to obtain a successful handover report (SHR) after a successful handover" in the above-mentioned glossary section, which will not be elaborated here.

[0199] S1103. The terminal device sends a terminal information response to the network. Correspondingly, the network receives the terminal information response.

[0200] Among them, the terminal information response includes a successful handover report, and the successful handover report includes a cause indication.

[0201] In a possible implementation manner, the implementation process of S1103 may include: setting the value of the successful handover report in the terminal information response to the value of the successful handover report in the variable successful handover report. Then, the terminal device sends the terminal information response to the network.

[0202] In an example, when the terminal device meets a preset condition, the value of the successful handover report in the terminal information response is set to the value of the successful handover report in the variable successful handover report.

[0203] Optionally, for the specific implementation process of the terminal device to set the value of the successful handover report in the terminal information response to the value of the successful handover report in the variable successful handover report, refer to step 5 in the "process for the terminal device to enable the network to obtain a successful handover report (SHR) after a successful handover" in the above-mentioned glossary section, which will not be elaborated here.

[0204] Further, after S1103, after the terminal device confirms the successful transmission of the terminal information response message, it discards the variable successful handover report.

[0205] Based on the above technical solution, the terminal device sends indication information to the network, and then the network sends a terminal information request to the terminal device, and the terminal device sends a terminal information response to the network based on the terminal information request. Among them, the terminal information response includes a successful switching report, and the successful switching report includes a cause indication. The above technical solution reports a successful switching report including a cause indication to the network so that the network can obtain the cause indication, thereby clarifying the optimization target of the cell switching, and then optimizing the cell switching process in a targeted manner, thereby improving the reliability of the cell switching.

[0206] As a possible embodiment of the present application, Figure 12 As shown, the cause reporting method may include the following steps 1-7.

[0207] 1. The network sends a successful handover report configuration information. Correspondingly, the terminal device receives the successful handover report configuration information.

[0208] Among them, step 1 is an optional step.

[0209] 2. When receiving the successful switching report configuration information, the terminal device records the reason indication in the successful switching report if the successful switching report configuration information is met.

[0210] 3. When the terminal device does not receive the successful switching report configuration information, if the preset configuration information is met and the conditions for successfully performing the RACH-based LTM cell switching after the failure of the LTM cell switching skipping RACH are met, the reason indication is recorded in the successful switching report.

[0211] 4. The terminal device sends the indication information, and the network receives the indication information accordingly.

[0212] The indication information is used to indicate that the terminal device stores a successful switching report.

[0213] 5. The network sends a terminal information request to the terminal device, and the terminal device receives the terminal information request accordingly.

[0214] 6. The terminal device sets the value of the successful switching report in the terminal information response to the value of the successful switching report in the variable successful switching report.

[0215] 7. The terminal device sends a terminal information response to the network, and the network receives the terminal information response accordingly.

[0216] The terminal information response includes a successful switching report, and the successful switching report includes a reason indication.

[0217] Embodiments of the present application can divide the cause reporting device into functional modules or functional units according to the above method examples. For example, each functional module or functional unit can be corresponding to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware, or in the form of a software functional module or functional unit. Among them, the division of modules or units in the embodiments of the present application is illustrative, and is only a logical function division. There can be other division methods in actual implementation.

[0218] As Figure 13 shown, it is a schematic structural diagram of a cause reporting device 130 provided by an embodiment of the present application. The cause reporting device 130 includes: a communication unit 1301 and a processing unit 1302.

[0219] The communication unit 1301 is configured to send a successful handover report when the LTM cell handover based on RACH is successful; wherein, the successful handover report includes a cause indication, and the cause indication is used to indicate the reason for the successful execution of the LTM cell handover based on RACH by the terminal device.

[0220] In a possible implementation manner, the communication unit 1301 is further configured to: receive successful handover report configuration information; the successful handover report configuration information is used to indicate that the terminal device reports a cause indication when the LTM cell handover based on RACH is successful.

[0221] The processing unit 1302 is configured to: record a cause indication in the successful handover report based on the successful handover report configuration information.

[0222] In a possible implementation manner, the communication unit 1301 is further configured to: send indication information to the network, and the indication information is used to indicate that the terminal device stores a successful handover report.

[0223] In a possible implementation manner, the reason indicated by the cause indication is any one of the following: the terminal device receives skip RACH configuration information and successfully executes the LTM cell handover based on RACH; the terminal device does not receive skip RACH configuration information and successfully executes the LTM cell handover based on RACH.

[0224] In a possible implementation, the terminal device receives the configuration information for skipping the RACH and successfully executes the LTM cell handover based on the RACH, which is used to indicate any of the following: The terminal device is configured to obtain the timing advance TA value based on the measurement of the terminal device, and no valid TA value is obtained through the measurement of the terminal device; The terminal device is configured to obtain the TA value based on the downlink control information configured by the network, and no valid TA value is obtained through the downlink control information configured by the network; The terminal device is configured to obtain the timing advance TA value based on the measurement of the terminal device and the TA value based on the downlink control information configured by the network, and no valid TA value is obtained.

[0225] In a possible implementation, the cause reporting device 130 may further include a storage unit 1303 ( Figure 13 shown by the dashed box in the figure), and the storage unit 1303 stores a program or instruction. When the processing unit 1302 executes the program or instruction, the cause reporting device 130 can execute the cause reporting method described in the above method embodiments.

[0226] As Figure 14 shown, it is a schematic structural diagram of a cause reporting device 140 provided by an embodiment of the present application. The cause reporting device 140 includes: a communication unit 1401.

[0227] The communication unit 1401 is configured to receive a handover success report; wherein, the successful handover report includes a cause indication, and the cause indication is used to indicate the reason for the successful execution of the LTM cell handover based on the RACH by the terminal device.

[0228] In a possible implementation, the communication unit 1401 is further configured to: send successful handover report configuration information; the successful handover report configuration information is used to indicate that the terminal device reports the cause indication when the LTM cell handover based on the RACH is successfully executed.

[0229] In a possible implementation, the communication unit 1401 is further configured to: receive indication information; the indication information is used to indicate that the terminal device stores a successful handover report.

[0230] In a possible implementation, the reason indicated by the cause indication is any of the following: The terminal device receives the configuration information for skipping the RACH and successfully executes the LTM cell handover based on the RACH; The terminal device does not receive the configuration information for skipping the RACH and successfully executes the LTM cell handover based on the RACH.

[0231] In a possible implementation, the terminal device receives the configuration information for skipping the RACH and successfully performs the LTM cell handover based on the RACH, which is used to indicate any one of the following: the terminal device is configured to obtain the timing advance (TA) value based on the measurement of the terminal device, and no valid TA value is obtained through the measurement of the terminal device; the terminal device is configured to obtain the TA value based on the downlink control information configured by the network, and no valid TA value is obtained through the downlink control information configured by the network; the terminal device is configured to obtain the TA value based on the measurement of the terminal device and the TA value based on the downlink control information configured by the network, and no valid TA value is obtained.

[0232] In a possible implementation, the cause reporting device 140 may further include a storage unit 1402 ( Figure 14 shown in a dashed box), and the storage unit 1402 stores programs or instructions. When the communication unit 1401 executes the programs or instructions, the cause reporting device 140 can perform the cause reporting method described in the foregoing method embodiments.

[0233] Through the description of the above embodiments, those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the above division of each functional module is used as an example. In actual applications, the above functions can be allocated to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. The specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be repeated here.

[0234] The embodiments of the present application provide a computer program product containing instructions. When the computer program product runs on a computer, the computer is caused to execute the cause reporting method in the foregoing method embodiments.

[0235] The embodiments of the present application further provide a computer-readable storage medium. Instructions are stored in the computer-readable storage medium. When the instructions run on a computer, the computer is caused to execute the cause reporting method in the method flow shown in the foregoing method embodiments.

[0236] Among them, a computer-readable storage medium can be, for example, but not limited to, a system, device, or component of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of the computer-readable storage medium include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a register, a hard disk, an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above, or any other form of computer-readable storage medium well-known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an application specific integrated circuit (ASIC). In the embodiments of the present application, the computer-readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, device, or component.

[0237] Since the cause reporting device, computer-readable storage medium, and computer program product in the embodiments of the present application can be applied to the above method, the technical effects they can obtain can also refer to the method embodiments above, and are not elaborated herein in the embodiments of the present application.

[0238] In several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be in an electrical, mechanical, or other form.

[0239] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of this disclosure can be achieved, and no limitations are imposed herein.

[0240] The above specific embodiments do not constitute a limitation on the protection scope of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub - combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure shall be included within the protection scope of this disclosure.

[0241] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0242] In addition, in each embodiment of this application, the functional units can be integrated in one processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0243] The above is only the specific embodiment of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A method for reporting a cause, characterized in that: Applied to a terminal device, the method comprises: In case of successful LTM cell switching triggered by layer 1 and 2 of random access RACH, a successful switching report is sent; wherein the successful switching report includes a cause indication, and the cause indication is used to indicate the reason why the terminal device successfully performs the LTM cell switching based on RACH.

2. The method according to claim 1, characterized in that The method further comprises: Receive successful switching report configuration information; the successful switching report configuration information is used to instruct the terminal device to report the cause indication when the RACH-based LTM cell switching is successfully performed.

3. The method according to claim 2, characterized in that The method further comprises: Based on the successful handover report configuration information, the cause indication is recorded in the successful handover report.

4. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: Sending indication information to the network, wherein the indication information is used to indicate that the terminal device stores the successful switching report.

5. The method according to claim 1, characterized in that The reason indicated by the reason indication is any one of the following: The terminal device receives the configuration information for skipping RACH and performs RACH-based LTM cell switching successfully; The terminal device does not receive the configuration information for skipping RACH and executes RACH-based LTM cell switching successfully.

6. The method according to claim 5, characterized in that The terminal device receives the configuration information of skipping RACH and performs the RACH-based LTM cell switching successfully, which is used to indicate any of the following: The terminal device is configured with a timing advance TA value acquisition based on terminal device measurement, and a valid TA value is not acquired through the terminal device measurement; The terminal device is configured to obtain the TA value based on the downlink control information configured by the network, but fails to obtain a valid TA value through the downlink control information configured by the network; The terminal device is configured with the timing advance TA value acquisition based on the terminal device measurement and the TA value acquisition based on the downlink control information configured by the network, but no valid TA value is acquired.

7. A method for reporting a cause, characterized in that: Applied to a network, the method comprises: Receive a handover success report; wherein the handover success report includes a cause indication, and the cause indication is used to indicate the reason why the terminal device successfully performs the RACH-based LTM cell handover.

8. The method according to claim 7, characterized in that The method further comprises: Sending successful switching report configuration information; the successful switching report configuration information is used to instruct the terminal device to report the cause indication when the RACH-based LTM cell switching is successful.

9. The method according to claim 7 or 8, characterized in that: The method further comprises: Receive indication information; the indication information is used to indicate that the terminal device stores the successful switching report.

10. The method according to claim 7, characterized in that The reason indicated by the reason indication is any one of the following: The terminal device receives the configuration information for skipping RACH and performs RACH-based LTM cell switching successfully; The terminal device does not receive the configuration information for skipping RACH and executes RACH-based LTM cell switching successfully.

11. The method according to claim 10, characterized in that The terminal device receives the configuration information of skipping RACH and performs the RACH-based LTM cell switching successfully, which is used to indicate any of the following: The terminal device is configured with a timing advance TA value acquisition based on terminal device measurement, and a valid TA value is not acquired through the terminal device measurement; The terminal device is configured to obtain the TA value based on the downlink control information configured by the network, but fails to obtain a valid TA value through the downlink control information configured by the network; The terminal device is configured with the timing advance TA value acquisition based on the terminal device measurement and the TA value acquisition based on the downlink control information configured by the network, but no valid TA value is acquired.

12. A communication device, characterized in that: include: A processor and a communication interface; the communication interface is coupled to the processor, and the processor is used to run a computer program or instruction to implement the cause reporting method as described in any one of claims 1-6 or claims 7-11.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions. When a computer executes the instructions, the computer executes the cause reporting method according to any one of claims 1 to 6 or claims 7 to 11.

14. A computer program product, characterized in that The computer program product includes computer instructions, and when the computer instructions are executed on a computer, the computer is enabled to execute the cause reporting method according to any one of claims 1 to 6 or claims 7 to 11.

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