Communication method, apparatus and system

Abstract

The present application provides a communication method, apparatus and system, which can be suitable for an LTM scenario. In the method, when a connection failure occurs, a terminal device records the cause of the connection failure and related information about the mobility process, and reports same to a network device, so that the network device can optimize related parameters, and an interrupt delay caused by the connection failure can be reduced.

Description

Communication method, device and system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 30, 2023, with application number 202311626632.4 and invention name “Communication Method, Device and System”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and in particular to a communication method, device, and system. Background Art

[0003] To identify mobility-related anomalies such as radio link failure, handover failure, and radio link failure in the target cell, user equipment (UE) can record and report mobility-related anomaly parameters to the network device, namely, a radio link failure report (RLF report). The network device can then optimize the UE's mobility parameters based on the RLF report. However, the current RLF report mechanism does not support mobility scenarios triggered by Layer 1 / Layer 2 signaling (L1 / L1 triggered mobility, LTM).

[0004] Summary of the Invention

[0005] The present application provides a communication method, device, and system that can analyze the cause of failure in an LTM scenario, thereby adjusting LTM-related parameters to reduce the recording of mobility anomalies and improve user experience.

[0006] In the first aspect, a communication method is provided, which can be executed by a terminal device, or by a chip or circuit used for the terminal device, or by a logic module or software that can realize all or part of the functions of the terminal device. This application does not limit this.

[0007] The method includes: receiving first information, the first information indicating that the terminal device switches from a source cell to a target cell, the target cell belongs to at least one candidate cell, the configuration information of the target cell belongs to the configuration information of the at least one candidate cell received by the terminal device, and the first information is sent via a media access control control element; recording a first report, the first report is used to indicate the reason for the connection failure during the terminal device's execution of layer 1 or layer 2 mobility; and sending the first report.

[0008] In this method, when a connection failure occurs in the LTM scenario, the terminal device can report the cause of the connection failure to the network device through a first report. Furthermore, other relevant information in the mobility process can also be reported in the first report, which facilitates the network device to perform root cause analysis and optimize related parameters, thereby improving the accuracy of the network device's optimization parameters and reducing the interruption delay caused by the connection failure.

[0009] In some implementations, the first report also indicates information about a first candidate cell, the information about the first candidate cell including identification information of the first candidate cell, whether the first candidate cell is configured with a random access response RAR, or at least one item of layer 1 reporting configuration information corresponding to the first candidate cell, and the first candidate cell is one or more of the at least one candidate cell.

[0010] In some implementations, the first report also indicates early advance timing information, and the early advance timing information includes whether the terminal device has performed early advance timing in the target cell, the candidate cell for performing the early advance timing, the number of physical downlink control channel instructions indicating the execution of the early advance timing to the candidate cell, physical random access channel resource information, synchronization signal block beam identifier or preamble code identifier.

[0011] In this manner, the network side optimizes the early timing-related processes and parameters based on the first report, thereby increasing the probability of random access-free switching and reducing data transmission interruption time.

[0012] In certain implementations, the connection failure includes a radio link failure of the source cell, and a cause of the radio link failure includes at least one of the following:

[0013] The first timer expires, that is, the running length of the first timer is greater than or equal to the first threshold value, wherein the running length of the first timer is the time from when the terminal device detects a physical layer desynchronization problem with the source network device to when the terminal device receives the first information;

[0014] The second timer expires, that is, the running length of the second timer is greater than or equal to the second threshold value, wherein the running length of the second timer is the length of time from the terminal device triggering the measurement report to the terminal device receiving the first information during the running of the first timer.

[0015] In some implementations, the cause of the wireless link failure also includes at least one of random access failure, beam failure recovery failure, listen-before-speak failure, and the number of wireless link layer control protocol retransmissions being greater than or equal to a fifth threshold value.

[0016] In some implementations, the first report also indicates the source cell radio link failure information, and the source cell radio link failure information includes at least one of the following: the layer 1 measurement result or layer 3 measurement result available when the failure is detected, the connection failure type is radio link failure, the cell with the radio link failure is the source cell, or the time from the terminal device receiving the configuration information of the at least one candidate cell to the terminal device detecting the source cell radio link failure.

[0017] In the above implementation, when a connection failure occurs in the source cell, the terminal device promptly reports the failure cause and related information to the network device, so that the network side can analyze the failure cause of the RLF of the source cell, thereby optimizing the mobility parameters and reducing the probability of the terminal device experiencing RLF in the source cell due to late switching.

[0018] In some implementations, the connection failure includes a handover failure of the terminal device or a handover failure within a first time period after a successful handover, where the first time period is predefined or configured.

[0019] That is, the terminal device fails to switch or fails soon after switching successfully.

[0020] In some implementations, the first report further indicates at least one of the following:

[0021] the identifier of the target cell,

[0022] Whether the target cell has an available advance timing value,

[0023] The access type used by the terminal device to access the target cell, the access type is random access-free or random access, or the access type is random access-free, or whether the access type is random access-free.

[0024] The target cell is used for uplink or downlink data transmission beam indication information,

[0025] an identifier of a first cell, the first cell being a cell having an available advance timing value, the first cell belonging to one or more of the at least one candidate cell;

[0026] First time information, where the first time information includes at least one of the following:

[0027] The duration from when the terminal device receives the configuration information of the at least one candidate cell to when the terminal device receives the first information or when the terminal device initiates cell handover,

[0028] The time from when the terminal device receives the first physical downlink control channel PDCCH instruction to when the terminal device receives the first information or the time when the terminal device initiates cell handover,

[0029] The time duration from when the terminal device receives the last physical downlink control channel PDCCH instruction to when the terminal device receives the first information or when the terminal device initiates cell switching.

[0030] In some implementations, the first report further indicates at least one of the following:

[0031] The type of connection failure, where the type of connection failure is handover failure or radio link failure;

[0032] The reason for the handover failure, wherein the reason for the handover failure includes at least one of the following:

[0033] The third timer expires, that is, the running length of the third timer is greater than or equal to the third threshold value, and the running length of the third timer is the time from the terminal device receiving the first information to the terminal device completing random access or the terminal device sending the first uplink data;

[0034] The fourth timer expires, that is, the running length of the fourth counter is greater than or equal to the fourth threshold value, and the running length of the fourth timer is the time from the terminal receiving or executing the RRC reconfiguration message with synchronization function to the terminal device completing random access or the terminal device receiving the physical control channel transmission after the first uplink transmission when random access is free;

[0035] The handover type of the last handover was Layer 1 or Layer 2 mobility handover;

[0036] Detecting that the cell where the connection failure occurs is the target cell;

[0037] Second time information, the second time information including the time from when the terminal device receives the last layer 1 or layer 2 mobility command to when the cell handover failure occurs, or the time from when the terminal device sends the first report,

[0038] Alternatively, the second time information includes the duration from the terminal device initiating cell handover to the occurrence of cell handover failure, or the duration from the terminal device sending the first report;

[0039] the running time of the third timer;

[0040] the running time of the fourth timer;

[0041] The layer 1 measurement results or layer 3 measurement results available when the detection fails;

[0042] The cell handover process information based on random access includes information of a two-step random access process and / or a four-step random access process.

[0043] In the above implementation, the terminal device records relevant information about the UE's failure to perform cell switching in the LTM scenario or failure that occurs soon after the switching is successful, and reports it to the network device, so that the network side can analyze the reasons for the failure to access the target cell or the failure in the target cell, thereby optimizing the corresponding mobility parameters and reducing the probability of premature switching or switching to the wrong cell.

[0044] On the second aspect, a communication method is provided, which can be executed by a network device, or by a chip or circuit used for a network device, or by a logic module or software that can realize all or part of the functions of the network device. This application does not limit this.

[0045] The method includes: sending first information, the first information indicating that the terminal device switches from a source cell to a target cell, the target cell belongs to at least one candidate cell, the configuration information of the target cell belongs to the configuration information of the at least one candidate cell received by the terminal device, and the first information is sent via a media access control control element; receiving a first report, the first report is used to indicate the reason for the connection failure during the terminal device's execution of layer 1 or layer 2 mobility.

[0046] In some implementations, the first report also indicates information about a first candidate cell, the information about the first candidate cell including identification information of the first candidate cell, whether the first candidate cell is configured with a random access response RAR, or at least one item of layer 1 reporting configuration information corresponding to the first candidate cell, and the first candidate cell is one or more of the at least one candidate cell.

[0047] In some implementations, the first report also indicates early advance timing information, and the early advance timing information includes whether the terminal device has performed early advance timing in the target cell, the candidate cell for performing the early advance timing, the number of physical downlink control channel instructions indicating the execution of the early advance timing to the candidate cell, physical random access channel resource information, synchronization signal block beam identifier or preamble code identifier.

[0048] In some implementations, the connection failure includes a radio link failure of the source cell.

[0049] The reason for the radio link failure includes at least one of the following:

[0050] The first timer expires, that is, the running length of the first timer is greater than or equal to the first threshold value, wherein the running length of the first timer is the time from when the terminal device detects a physical layer desynchronization problem with the source network device to when the terminal device receives the first information;

[0051] The second timer expires, that is, the running length of the second timer is greater than or equal to the second threshold value, wherein the running length of the second timer is the length of time from the terminal device triggering the measurement report to the terminal device receiving the first information during the running of the first timer.

[0052] In some implementations, the cause of the wireless link failure also includes at least one of random access failure, beam failure recovery failure, listen-before-speak failure, and the number of wireless link layer control protocol retransmissions being greater than or equal to a fifth threshold value.

[0053] In some implementations, the first report also indicates the source cell radio link failure information, and the source cell radio link failure information includes at least one of the following: the layer 1 measurement result or layer 3 measurement result available when the failure is detected, the connection failure type is radio link failure, the cell with the radio link failure is the source cell, or the time from the terminal device receiving the configuration information of the at least one candidate cell to the terminal device detecting the source cell radio link failure.

[0054] In some implementations, the connection failure includes a handover failure of the terminal device or a handover failure within a first time period after a successful handover, where the first time period is predefined or configured.

[0055] In some implementations, the first report further indicates at least one of the following:

[0056] the identifier of the target cell,

[0057] Whether the target cell has an available advance timing value,

[0058] The access type used by the terminal device to access the target cell is random access-free or random access, or the access type is random access-free

[0059] The target cell is used for uplink or downlink data transmission beam indication information,

[0060] an identifier of a first cell, the first cell being a cell having an available advance timing value, the first cell belonging to one or more of the at least one candidate cell;

[0061] First time information, where the first time information includes at least one of the following:

[0062] The duration from when the terminal device receives the configuration information of the at least one candidate cell to when the terminal device receives the first information or when the terminal device initiates cell handover,

[0063] The time from when the terminal device receives the first physical downlink control channel PDCCH instruction to when the terminal device receives the first information or the time when the terminal device initiates cell handover,

[0064] The time duration from when the terminal device receives the last physical downlink control channel PDCCH instruction to when the terminal device receives the first information or when the terminal device initiates cell switching.

[0065] In some implementations, the first report further indicates at least one of the following:

[0066] The type of connection failure, where the type of connection failure is handover failure or radio link failure;

[0067] The reason for the handover failure, wherein the reason for the handover failure includes at least one of the following:

[0068] The third timer expires, that is, the running time of the third timer is greater than or equal to the third threshold value,

[0069] The running time of the third timer is the time from when the terminal device receives the first information to when the terminal device completes random access or sends the first uplink data;

[0070] The fourth timer expires, that is, the running length of the fourth counter is greater than or equal to the fourth threshold value, and the running length of the fourth timer is the time from the terminal receiving or executing the RRC reconfiguration message with synchronization function to the terminal device completing random access or the terminal device receiving the physical control channel transmission after the first uplink transmission when random access is free;

[0071] The handover type of the last handover was Layer 1 or Layer 2 mobility handover;

[0072] Detecting that the cell where the connection failure occurs is the target cell;

[0073] Second time information, the second time information including the time from when the terminal device receives the last layer 1 or layer 2 mobility command to when the cell handover failure occurs, or the time from when the terminal device sends the first report,

[0074] Alternatively, the second time information includes the duration from the terminal device initiating cell handover to the occurrence of cell handover failure, or the duration from the terminal device sending the first report;

[0075] the running time of the third timer;

[0076] the running time of the fourth timer;

[0077] The layer 1 measurement results or layer 3 measurement results available when the detection fails;

[0078] The cell handover process information based on random access includes information of a two-step random access process and / or a four-step random access process.

[0079] It should be understood that the second aspect is an implementation method on the network device side corresponding to the first aspect. The explanations, supplements and descriptions of the beneficial effects of the first aspect are also applicable to the second aspect and will not be repeated here.

[0080] According to a third aspect, a communication device is provided, comprising a transceiver unit and a processing unit, the transceiver unit being used to receive first information, the first information indicating that a terminal device switches from a source cell to a target cell, the target cell belonging to at least one candidate cell, the configuration information of the target cell belonging to the configuration information of the at least one candidate cell received by the terminal device, and the first information being sent via a media access control control element; the processing unit being used to record a first report, the first report being used to indicate a cause of connection failure during the process of the terminal device performing layer 1 or layer 2 mobility; the sending unit being further used to send the first report.

[0081] In some implementations, the first report also indicates information about a first candidate cell, the information about the first candidate cell including identification information of the first candidate cell, whether the first candidate cell is configured with a random access response RAR, or at least one item of layer 1 reporting configuration information corresponding to the first candidate cell, and the first candidate cell is one or more of the at least one candidate cell.

[0082] In some implementations, the first report also indicates early advance timing information, and the early advance timing information includes whether the terminal device has performed early advance timing in the target cell, the candidate cell for performing the early advance timing, the number of physical downlink control channel instructions indicating the execution of the early advance timing to the candidate cell, physical random access channel resource information, synchronization signal block beam identifier or preamble code identifier.

[0083] In certain implementations, the connection failure includes a radio link failure of the source cell, and a cause of the radio link failure includes at least one of the following:

[0084] The first timer expires, that is, the running length of the first timer is greater than or equal to the first threshold value, wherein the running length of the first timer is the time from when the terminal device detects a physical layer desynchronization problem with the source network device to when the terminal device receives the first information;

[0085] The second timer expires, that is, the running length of the second timer is greater than or equal to the second threshold value, wherein the running length of the second timer is the length of time from the terminal device triggering the measurement report to the terminal device receiving the first information during the running of the first timer.

[0086] In some implementations, the cause of the wireless link failure also includes at least one of random access failure, beam failure recovery failure, listen-before-speak failure, and the number of wireless link layer control protocol retransmissions being greater than or equal to a fifth threshold value.

[0087] In some implementations, the first report also indicates the source cell radio link failure information, and the source cell radio link failure information includes at least one of the following: the layer 1 measurement result or layer 3 measurement result available when the failure is detected, the connection failure type is radio link failure, the cell with the radio link failure is the source cell, or the time from the terminal device receiving the configuration information of the at least one candidate cell to the terminal device detecting the source cell radio link failure.

[0088] In the above implementation, when a connection failure occurs in the source cell, the terminal device promptly reports the failure cause and related information to the network device, so that the network side can analyze the failure cause of the RLF of the source cell, thereby optimizing the mobility parameters and reducing the probability of the terminal device experiencing RLF in the source cell due to late switching.

[0089] In some implementations, the connection failure includes a handover failure of the terminal device or a handover failure within a first time period after a successful handover, where the first time period is predefined or configured.

[0090] That is, the terminal device fails to switch or fails soon after switching successfully.

[0091] In some implementations, the first report further indicates at least one of the following:

[0092] the identifier of the target cell,

[0093] Whether the target cell has an available advance timing value,

[0094] The access type used by the terminal device to access the target cell is random access-free or random access, or the access type is random access-free,

[0095] The target cell is used for uplink or downlink data transmission beam indication information,

[0096] an identifier of a first cell, the first cell being a cell having an available advance timing value, the first cell belonging to one or more of the at least one candidate cell;

[0097] First time information, where the first time information includes at least one of the following:

[0098] The duration from when the terminal device receives the configuration information of the at least one candidate cell to when the terminal device receives the first information or when the terminal device initiates cell handover,

[0099] The time from when the terminal device receives the first physical downlink control channel PDCCH instruction to when the terminal device receives the first information or the time when the terminal device initiates cell handover,

[0100] The time duration from when the terminal device receives the last physical downlink control channel PDCCH instruction to when the terminal device receives the first information or when the terminal device initiates cell switching.

[0101] In some implementations, the first report further indicates at least one of the following:

[0102] The type of connection failure, where the type of connection failure is handover failure or radio link failure;

[0103] The reason for the handover failure, wherein the reason for the handover failure includes at least one of the following:

[0104] The third timer expires, that is, the running time of the third timer is greater than or equal to the third threshold value,

[0105] The running time of the third timer is the time from when the terminal device receives the first information to when the terminal device completes random access or sends the first uplink data;

[0106] The fourth timer expires, that is, the running length of the fourth counter is greater than or equal to the fourth threshold value, and the running length of the fourth timer is the time from the terminal receiving or executing the RRC reconfiguration message with synchronization function to the terminal device completing random access or the terminal device receiving the physical control channel transmission after the first uplink transmission when random access is free;

[0107] The handover type of the last handover was Layer 1 or Layer 2 mobility handover;

[0108] Detecting that the cell where the connection failure occurs is the target cell;

[0109] Second time information, the second time information including the time from when the terminal device receives the last layer 1 or layer 2 mobility command to when the cell handover failure occurs, or the time from when the terminal device sends the first report,

[0110] Alternatively, the second time information includes the duration from the terminal device initiating cell handover to the occurrence of cell handover failure, or the duration from the terminal device sending the first report;

[0111] the running time of the third timer;

[0112] the running time of the fourth timer;

[0113] The layer 1 measurement results or layer 3 measurement results available when the detection fails;

[0114] The cell handover process information based on random access includes information of a two-step random access process and / or a four-step random access process.

[0115] In a fourth aspect, a communication device is provided, comprising a transceiver unit, wherein the transceiver unit is used to send first information, wherein the first information indicates that a terminal device switches from a source cell to a target cell, the target cell belongs to at least one candidate cell, and the configuration information of the target cell belongs to the configuration information of the at least one candidate cell received by the terminal device, and the first information is sent via a media access control control element; the transceiver unit is also used to receive a first report, wherein the first report is used to indicate the cause of the connection failure during the terminal device's execution of layer 1 or layer 2 mobility.

[0116] In some implementations, the first report also indicates information about a first candidate cell, the information about the first candidate cell including identification information of the first candidate cell, whether the first candidate cell is configured with a random access response RAR, or at least one item of layer 1 reporting configuration information corresponding to the first candidate cell, and the first candidate cell is one or more of the at least one candidate cell.

[0117] In some implementations, the first report also indicates early advance timing information, and the early advance timing information includes whether the terminal device has performed early advance timing in the target cell, the candidate cell for performing the early advance timing, the number of physical downlink control channel instructions indicating the execution of the early advance timing to the candidate cell, physical random access channel resource information, synchronization signal block beam identifier or preamble code identifier.

[0118] In some implementations, the connection failure includes a radio link failure of the source cell.

[0119] The reason for the radio link failure includes at least one of the following:

[0120] The first timer expires, that is, the running length of the first timer is greater than or equal to the first threshold value, wherein the running length of the first timer is the time from when the terminal device detects a physical layer desynchronization problem with the source network device to when the terminal device receives the first information;

[0121] The second timer expires, that is, the running length of the second timer is greater than or equal to the second threshold value, wherein the running length of the second timer is the length of time from the terminal device triggering the measurement report to the terminal device receiving the first information during the running of the first timer.

[0122] In some implementations, the cause of the wireless link failure also includes at least one of random access failure, beam failure recovery failure, listen-before-speak failure, and the number of wireless link layer control protocol retransmissions being greater than or equal to a fifth threshold value.

[0123] In some implementations, the first report also indicates the source cell radio link failure information, and the source cell radio link failure information includes at least one of the following: the layer 1 measurement result or layer 3 measurement result available when the failure is detected, the connection failure type is radio link failure, the cell with the radio link failure is the source cell, or the time from the terminal device receiving the configuration information of the at least one candidate cell to the terminal device detecting the source cell radio link failure.

[0124] In some implementations, the connection failure includes a handover failure of the terminal device or a handover failure within a first time period after a successful handover, where the first time period is predefined or configured.

[0125] In some implementations, the first report further indicates at least one of the following:

[0126] the identifier of the target cell,

[0127] Whether the target cell has an available advance timing value,

[0128] The access type used by the terminal device to access the target cell is random access-free or random access, or the access type is random access-free,

[0129] The target cell is used for uplink or downlink data transmission beam indication information,

[0130] an identifier of a first cell, the first cell being a cell having an available advance timing value, the first cell belonging to one or more of the at least one candidate cell;

[0131] First time information, where the first time information includes at least one of the following:

[0132] The duration from when the terminal device receives the configuration information of the at least one candidate cell to when the terminal device receives the first information or when the terminal device initiates cell handover,

[0133] The time from when the terminal device receives the first physical downlink control channel PDCCH instruction to when the terminal device receives the first information or the time when the terminal device initiates cell handover,

[0134] The time duration from when the terminal device receives the last physical downlink control channel PDCCH instruction to when the terminal device receives the first information or when the terminal device initiates cell switching.

[0135] In some implementations, the first report further indicates at least one of the following:

[0136] The type of connection failure, where the type of connection failure is handover failure or radio link failure;

[0137] The reason for the handover failure, wherein the reason for the handover failure includes at least one of the following:

[0138] The third timer expires, that is, the running time of the third timer is greater than or equal to the third threshold value,

[0139] The running time of the third timer is the time from when the terminal device receives the first information to when the terminal device completes random access or sends the first uplink data;

[0140] The fourth timer expires, that is, the running length of the fourth counter is greater than or equal to the fourth threshold value, and the running length of the fourth timer is the time from the terminal receiving or executing the RRC reconfiguration message with synchronization function to the terminal device completing random access or the terminal device receiving the physical control channel transmission after the first uplink transmission when random access is free;

[0141] The handover type of the last handover was Layer 1 or Layer 2 mobility handover;

[0142] Detecting that the cell where the connection failure occurs is the target cell;

[0143] Second time information, the second time information including the time from when the terminal device receives the last layer 1 or layer 2 mobility command to when the cell handover failure occurs, or the time from when the terminal device sends the first report,

[0144] Alternatively, the second time information includes the duration from the terminal device initiating cell handover to the occurrence of cell handover failure, or the duration from the terminal device sending the first report;

[0145] the running time of the third timer;

[0146] the running time of the fourth timer;

[0147] The layer 1 measurement results or layer 3 measurement results available when the detection fails;

[0148] The cell handover process information based on random access includes information of a two-step random access process and / or a four-step random access process.

[0149] In a fifth aspect, the present application provides a communication device, comprising an interface circuit and a processor, wherein the interface circuit is used to implement the function of the transceiver module in the third aspect, and the processor is used to implement the function of the processing module in the third aspect.

[0150] In a sixth aspect, the present application provides a communication device, comprising an interface circuit and a processor, wherein the interface circuit is used to implement the function of the transceiver module in the fourth aspect, and the processor is used to implement the function of the processing module in the sixth aspect.

[0151] In the seventh aspect, the present application provides a computer-readable medium storing a program code for execution on a terminal device, the program code comprising instructions for executing the method of the first aspect, or any possible manner in the first aspect, or all possible manners in the first aspect.

[0152] In an eighth aspect, an embodiment of the present application provides a computer-readable medium storing a program code for execution by a network device, the program code including instructions for executing the method of the second aspect, or the third aspect, or any possible manner in the second aspect, or any possible manner in the third aspect, or all possible manners in the second aspect, or all possible manners in the third aspect.

[0153] In the ninth aspect, a computer program product storing computer-readable instructions is provided, which, when the computer-readable instructions are executed on a computer, enables the computer to execute the method of the first aspect, or any possible method of the first aspect, or all possible methods of the first aspect.

[0154] In the tenth aspect, a computer program product storing computer-readable instructions is provided, which, when the computer-readable instructions are run on a computer, enables the computer to execute the method of the above-mentioned second aspect, or any possible method of the second aspect, or all possible methods of the second aspect.

[0155] In the eleventh aspect, a communication system is provided, which includes a device having functions of implementing the above-mentioned first aspect, or any possible manner in the first aspect, or all possible manners in the first aspect, the second aspect, or any possible manner in the second aspect, or all possible manners in the second aspect, and various possible designed functions.

[0156] In the twelfth aspect, a processor is provided, which is coupled to a memory and is used to execute the method of the above-mentioned first aspect, or any possible method of the first aspect, or all possible methods of the first aspect.

[0157] In a thirteenth aspect, a processor is provided, coupled to a memory, for executing the method of the second aspect, or any possible manner of the second aspect, or all possible manners of the second aspect.

[0158] In a fourteenth aspect, a chip system is provided, comprising a processor and a memory configured to execute computer programs or instructions stored in the memory, so that the chip system implements the method of any of the aforementioned first or second aspects, as well as any possible implementation of either aspect. The chip system may be composed of a chip alone, or may include a chip and other discrete components. BRIEF DESCRIPTION OF THE DRAWINGS

[0159] FIG1 is a schematic diagram of a wireless communication system applicable to an embodiment of the present application.

[0160] FIG2 is a schematic diagram of a protocol stack applicable to an embodiment of the present application.

[0161] FIG3 is a schematic diagram of an ORAN system applicable to an embodiment of the present application.

[0162] FIG4 is a schematic flowchart of a contention-based four-step random access provided in an embodiment of the present application.

[0163] FIG5 is a schematic flowchart of a contention-based two-step random access provided in an embodiment of the present application.

[0164] FIG6 is a schematic diagram of a communication method provided in an embodiment of the present application.

[0165] FIG7 is a flow chart of a communication method provided in an embodiment of the present application.

[0166] FIG8 is a schematic diagram of two switching processes provided in an embodiment of the present application.

[0167] FIG9 is a flow chart of another communication method provided in an embodiment of the present application.

[0168] FIG10 shows a schematic block diagram of a communication device provided in an embodiment of the present application.

[0169] FIG11 shows a schematic structural diagram of a communication device provided in an embodiment of the present application.

[0170] FIG12 shows a schematic diagram of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0171] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0172] The technical solutions provided in this application can be applied to various communication systems, such as: fifth generation (5G) or new radio (NR) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, etc. The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system. The technical solutions provided in this application can also be applied to device to device (D2D) communication, vehicle-to-everything (V2X) communication, machine to machine (M2M) communication, machine type communication (MTC), and Internet of Things (IoT) communication systems or other communication systems.

[0173] The terminal devices in the embodiments of the present application include various devices with wireless communication functions, which can be used to connect people, objects, machines, etc. The terminal devices can be widely used in various scenarios, such as: cellular communication, D2D, V2X, peer to peer (P2P), M2M, MTC, IoT, virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery, etc. The terminal device can be a terminal in any of the above scenarios, such as an MTC terminal, an IoT terminal, etc. The terminal device may be a user equipment (UE) of the third generation partnership project (3GPP) standard, a terminal, a fixed device, a mobile station device or a mobile device, a subscriber unit, a handheld device, a vehicle-mounted device, a wearable device, a cellular phone, a smart phone, a SIP phone, a wireless data card, a personal digital assistant (PDA), a computer, a tablet computer, a notebook computer, a wireless modem, a handheld device, a laptop computer, a computer with wireless transceiver function, a smart book, a vehicle, a satellite, a global positioning system (GPS) device, a target tracking device, an aircraft (such as a drone, a helicopter, a multi-copter, a quadcopter, or an airplane), a ship, a remote control device, a smart home device, an industrial device, or a device built into the above-mentioned device (such as a communication module, a modem or a chip in the above-mentioned device), or other processing devices connected to a wireless modem. For ease of description, the terminal device will be described below by taking the terminal or UE as an example.

[0174] It should be understood that in some scenarios, a UE can also be used to act as a base station. For example, a UE can act as a scheduling entity that provides sidelink signals between UEs in scenarios such as V2X, D2D, or P2P.

[0175] In the embodiments of the present application, the device for implementing the function of the terminal device can be the terminal device, or it can be a device that can support the terminal device to implement the function, such as a chip system or chip, which can be installed in the terminal device. In the embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0176] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. Base station can broadly cover various names as follows, or replace the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmission point (TRP), transmission point (TP), master station, auxiliary station, multi-standard wireless (motor slide retainer, MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. The base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. The base station can also refer to a communication module, modem or chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs base station functions in D2D, V2X, and M2M communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. The base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form used by the network equipment.

[0177] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0178] In the embodiments of the present application, the device for implementing the function of the network device can be a terminal device, or a device that can support the network device to implement the function, such as a chip system or chip, which can be installed in the network device. In the embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0179] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0180] First, a brief introduction to the network architecture applicable to the embodiments of the present application is given as follows.

[0181] FIG1 is a schematic diagram of a wireless communication system 100 applicable to an embodiment of the present application. As shown in FIG1 , the wireless communication system 100 may include at least one network device, such as the network device 110a shown in FIG1 . The wireless communication system 100 may also include at least one terminal device, such as the terminal device 120a and the terminal device 120b shown in FIG1 . Both the network device and the terminal device may be configured with multiple antennas, and the network device and the terminal device may communicate using multi-antenna technology. Terminal devices may also communicate with each other. For example, terminal devices may communicate directly with each other. For another example, terminal devices may communicate with each other through other communication devices, such as network devices or other terminal devices.

[0182] When a network device communicates with a terminal device, the network device can manage one or more cells, and a cell can have an integer number of terminal devices. Optionally, network device 110a and terminal device 120a form a single-cell communication system. Without loss of generality, the cell is referred to as cell #1. Network device 110a can be a network device in cell #1, or network device 110a can serve a terminal device (e.g., terminal device 120a) in cell #1.

[0183] It should be noted that a cell can be understood as an area within the coverage range of wireless signals of network equipment.

[0184] It should be understood that Figure 1 is a simplified schematic diagram for ease of understanding, and the wireless communication system 100 may also include other network devices or other terminal devices, which are not shown in Figure 1. The embodiments of the present application can be applied to any communication scenario in which a transmitting device and a receiving device communicate.

[0185] 1) The terminal 120 may also be referred to as a terminal device, user equipment (UE), mobile station, mobile terminal, etc. The terminal can be widely used in various scenarios, for example, device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IOT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, etc. The terminal may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a robotic arm, a smart home device, etc. The embodiments of the present application do not limit the device form of the terminal.

[0186] 2) RAN node 110, sometimes also referred to as access network equipment, RAN entity or access node, etc., constitutes a part of the communication system to help terminals achieve wireless access. The multiple RAN nodes 110 in the communication system 1000 can be nodes of the same type or different types. In some scenarios, the roles of the RAN node 110 and the terminal 120 are relative. For example, the network element 120i in Figure 1 can be a helicopter or a drone, which can be configured as a mobile base station. For those terminals 120j that access the RAN 100 through the network element 120i, the network element 120i is a base station; but for the base station 110a, the network element 120i is a terminal. The RAN node 110 and the terminal 120 are sometimes referred to as communication devices. For example, the network elements 110a and 110b in Figure 1 can be understood as communication devices with base station functions, and the network elements 120a-120j can be understood as communication devices with terminal functions.

[0187] In one possible scenario, a RAN node may be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a sixth-generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. A RAN node may be a macro base station (such as 110a in Figure 1 ), a micro base station or an indoor station (such as 110b in Figure 1 ), a relay node or a donor node, or a wireless controller in a CRAN scenario. Alternatively, a RAN node may be a server, a wearable device, a vehicle, or an onboard device. For example, the access network device in vehicle-to-everything (V2X) technology may be a roadside unit (RSU).

[0188] In another possible scenario, multiple RAN nodes collaborate to assist terminals in achieving wireless access, with different RAN nodes implementing portions of the base station's functionality. For example, a RAN node can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be separate or included in the same network element, such as the baseband unit (BBU). The CU and DU nodes split the gNB's protocol layers, centrally controlling some protocol layer functions within the CU and distributing some or all of the remaining protocol layer functions within the DU, which is then centrally controlled by the CU. As an implementation method, as shown in Figure 2, the CU is deployed with the radio resource control (RRC) layer, the PDCP layer, and the service data adaptation protocol (SDAP) layer in the protocol stack; the DU is deployed with the radio link control (RLC) layer, the media access control (MAC) layer, and the physical layer (PHY) in the protocol stack. Thus, the CU has the processing capabilities of RRC, PDCP, and SDAP. The DU has the processing capabilities of RLC, MAC, and PHY. It will be understood that the above functional division is only an example and does not constitute a limitation on the CU and DU. The RU may be included in a radio frequency device or a radio frequency unit, for example, in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0189] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, CU may also be called O-CU (Open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the convenience of description, this application takes CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. The correspondence between ORAN's access network equipment (network element module) and its achievable protocol layer functions can be referred to Table 1.

[0190] Table 1. Correspondence between ORAN access network equipment (network element modules) and their achievable protocol layer functions

[0191] For example, FIG3 is a schematic diagram of an ORAN system, which may include one or more CUs, DUs, and RUs.

[0192] 3) Core network equipment refers to the equipment in the core network (CN) that provides service support for the terminal. At present, some examples of core network equipment are: access and mobility management function (AMF) entity, session management function (SMF) entity, user plane function (UPF) entity, etc., which are not listed here one by one. Among them, the AMF entity can be responsible for terminal access management and mobility management; the SMF entity can be responsible for session management, such as user session establishment, etc.; the UPF entity can be a functional entity of the user plane, mainly responsible for connecting to the external network. It should be noted that the entity in this application can also be referred to as a network element or a functional entity. For example, the AMF entity can also be referred to as an AMF network element or an AMF functional entity. For another example, the SMF entity can also be referred to as an SMF network element or an SMF functional entity, etc.

[0193] To facilitate understanding of the embodiments of the present application, the following is a brief explanation of the terms involved in the embodiments of the present application.

[0194] 1. Traditional (basic) switching

[0195] In traditional mobile communication systems, mobility management for connected UEs is controlled by network equipment during the traditional handover process. For example, the source base station sends an RRC reconfiguration message containing a handover command, instructing the UE on which target cell to handover to and how to perform the handover. Specifically, upon receiving the RRC reconfiguration message containing the handover command, the UE immediately releases the source cell, halts uplink and downlink data transmission with the source cell, and then connects to the target cell based on the handover command. Therefore, the successful transmission of the handover message is essential for successful handovers under traditional handover mechanisms.

[0196] 2. Conditional Handover (CHO)

[0197] The CHO mechanism can improve the success rate of handover. For example, when the quality of the source link is good, the source base station sends an RRC reconfiguration message containing CHO configuration information to the UE. The CHO configuration information may include the configuration information of one or more candidate cells, the execution trigger conditions or measurement configuration of the candidate cells, etc. After receiving the CHO configuration information, the UE will not immediately initiate a handover action to any candidate cell, but will continue to maintain the connection and data transmission with the source base station. After the UE finds a candidate cell that meets the execution trigger conditions among the candidate cells, it can independently determine the target cell and further initiate handover execution. Unlike CHO, under basic handover, after receiving the handover command, the UE will immediately perform handover to the target cell indicated by the handover command.

[0198] 3. Dual Active Protocol Stack (DAPS) switching

[0199] The DAPS switching mechanism can reduce the switching interruption time. Among them, the switching interruption time is the period of time during which the UE cannot transmit data with any base station during the switching. For example, the source base station indicates the target cell to the UE through an RRC reconfiguration message containing a switching command. The UE accesses the target cell according to the content contained in the switching command. During the switching execution (or access to the target cell), the UE will continue to transmit data with the source cell until the UE establishes a connection with the target cell for data transmission. Specifically, the UE can receive and send data with the source cell and the target cell at the same time in a short period of time:

[0200] The UE continues to receive downlink data from the source cell until the target cell instructs the UE to release the source cell;

[0201] The UE continues to send uplink user data to the source cell until it successfully randomly accesses the target cell.

[0202] DAPS handover places high demands on UE capabilities. From the UE's perspective, two protocol stacks are internally active during the DAPS handover process. One active protocol stack is used for transmitting and receiving user-plane data in the target cell; the other is used for transmitting and receiving user-plane data in the source cell. The source and target user-plane protocol stacks share a common PDCP entity, enabling both sides to share common reordering and deduplication functions.

[0203] 4. Random access (RA)

[0204] Random access is a necessary step for a UE to connect to a network. The RA process establishes a radio link between the terminal device and the network equipment, achieving uplink synchronization. After successful RA completion, the UE and the base station continue normal data transmission. Through random access, the UE can achieve uplink synchronization, obtain uplink resources (UL grant), and obtain a unique Cell Radio Network Temporary Identifier (C-RNTI).

[0205] RA is divided into contention-based four-step random access (4-step CBRA), non-contention-based four-step random access (4-step CFRA), contention-based two-step random access (2-step CBRA), and non-contention-based two-step random access (2-step CFRA). The following describes the 4-step CBRA and 2-step CBRA processes in detail.

[0206] Figure 4 shows a schematic flowchart of a 4-step CBRA provided in an embodiment of the present application. For ease of understanding, the terminal device is UE and the network device is gNB. As shown in Figure 4:

[0207] S410: The UE sends a random access preamble to the gNB.

[0208] Specifically, the UE sends a preamble to the gNB on a physical random access channel (PRACH) resource, such as a RACH Occasion.

[0209] For example, the gNB informs the UE of the time-frequency resource set of the PRACH in the current cell that can be used to transmit the preamble through a system message. When the UE initiates random access, it also needs to select (CBRA) or a PRACH resource specified by the base station (CFRA) to send the preamble.

[0210] S420: The gNB sends random access response information to the UE.

[0211] Specifically, after receiving the preamble from the UE, the gNB sends a random access response (RAR) to the UE. The RAR may indicate the resource location of the physical uplink shared channel (PUSCH).

[0212] The message 2 (msg2) may be referred to as message 2 below, and may include a preamble identifier, timing advance (TA) information, initial uplink grant (UL grant) information, and may also carry a temporary identifier of the UE.

[0213] S430: The UE sends a first request message to the gNB.

[0214] Specifically, the UE sends a first request information to the gNB through the PUSCH according to the resource location of the PUSCH indicated in the random access response information received from the gNB.

[0215] Optionally, the first request information includes an RRC setup request (RRC Setup Resuest) message or an RRC resume request (RRC Resume Resuest) message.

[0216] This first request message is hereinafter referred to as message 3 (msg3). The UE sends msg3 based on the UL grant information indicated in the RAR. msg3 may include Layer 2 or Layer 3 information, such as a BFR MAC CE or RRC message. msg3 may also include UE identification information, such as the UE's C-RNTI, the UE's Resume ID, or the UE's Inactive RNTI (I-RNTI).

[0217] S440: The gNB sends a first response message to the UE.

[0218] Specifically, after the gNB receives the first request information from the UE, the gNB sends a first response information to the UE.

[0219] Optionally, the first response information includes one or more of the following: an RRC Setup message, an RRC Resume message, an acknowledgement (ACK) / negative acknowledgement (NACK) of the physical uplink shared channel (PUSCH) in the first request information, and a power control command, etc.

[0220] That is, since the UE carries the UE identification information in step 430, if the UE contention resolution is successful, the gNB sends a contention resolution message to the UE, which includes the UE identification information.

[0221] Figure 4 above mainly introduces the specific process of information exchange between the UE and the gNB in ​​contention-based four-step random access (4-step CBRA).

[0222] Figure 5 shows a schematic flowchart of a 2-step CBRA provided in an embodiment of the present application. For ease of understanding, the terminal device is UE and the network device is gNB. As shown in Figure 5:

[0223] S510: The UE sends a second request to the gNB.

[0224] Specifically, the UE sends a second request message to the gNB on the PRACH resource and sends uplink data to the gNB through the PUSCH.

[0225] Optionally, the second request information includes a preamble, an RRC setup request (RRC Setup Resuest) message, or an RRC resume request (RRC Resume Resuest) message.

[0226] That is, the UE sends msgA, including the 2-step RACH preamble and the data sent on the PUSCH corresponding to the preamble.

[0227] S520: The gNB sends a second response message to the UE.

[0228] Specifically, after the gNB receives the second request information from the UE, the gNB sends a second response information to the UE.

[0229] Optionally, the second response information includes one or more of the following: an RRC Setup message, an RRC Resume message, a PUSCH response ACK / NACK and a power control command in the second request information, etc.

[0230] That is, the UE receives msgB. If the conflict is resolved successfully, the UE ends the RACH process.

[0231] Specifically, msgB typically includes one or more user RARs, which are categorized as SuccessRARs and FallbackRARs. The MAC layer indicates which RAR type is being used, which can be understood as a fallback indication. A SuccessRAR with a Contention Resolution ID indicates that the gNB detected the preamble and correctly decoded the data. If the Contention Resolution ID matches the content sent by the UE in msgA, contention resolution is considered successful. A FallbackRAR, similar in format to msg2, indicates that the gNB detected the preamble but failed to decode the data.

[0232] Figure 5 above mainly introduces the specific process of information exchange between the UE and the gNB in ​​contention-based two-step random access (2-step CBRA).

[0233] 5. L1 / L2 signaling triggered mobility (L1 / L1 triggered mobility, LTM)

[0234] LTM technology can also reduce the switching interruption time. Specifically, the network device sends an RRC reconfiguration message containing multiple candidate cell configuration information to the UE in advance. The candidate cell can be a cell managed by the same CU as the network device, or a cell managed by a different CU from the network side. The UE saves the configuration information of multiple candidate cells. The UE reports a layer 1 measurement report to the network device, and the network device instructs the UE to switch (cell switch) to the target cell through an L2 switching command (MAC CE). The UE switches (cell switch) to the target cell based on the stored target cell configuration information, and saves the configuration information of one or more candidate cells to support continuous switching. LTM supports early TA acquisition, RACH-less access and LTM supervision timer (also referred to as the third timer in the embodiment of the present application). In addition, the 304 timer has also been enhanced according to the LTM scenario.

[0235] 6. Mobility robustness optimization (MRO)

[0236] In order to reduce the problems of premature switching, unnecessary switching, late switching, and ping-pong switching in intra-frequency switching, inter-frequency switching, inter-system switching, etc. caused by unreasonable network parameter settings, the system currently supports the MRO mechanism. MRO is an important mechanism for network self-optimization. When an abnormal situation related to mobility occurs in the terminal device (such as radio link failure, switching failure, radio link failure in the target cell, etc.), the abnormal parameters related to mobility are reported to the network device. The network device can autonomously analyze and optimize the network parameters based on the relevant parameters reported by the terminal device. For example, MRO adjusts the mobility parameters based on the report reported by the terminal device to the network device, such as the radio link failure report (RLF report) and the successful handover report (SHR). Among them, the mobility parameters are parameters that may be used in the judgment of the handover process, such as the switching threshold.

[0237] 7.RLF report

[0238] The terminal device generally records an RLF report in the following two situations:

[0239] 1. The terminal device does not receive the handover message (for example, in a traditional handover or DAPS handover scenario), or receives a CHO configuration but does not trigger execution, resulting in a radio link failure (RLF).

[0240] 2. The terminal device performs a handover (such as a traditional handover, CHO or DAPS handover), but fails to access the target cell or an RLF occurs soon after accessing the target cell.

[0241] The RLF report includes at least one of the following information:

[0242] 1) failedPcellID: The identification information of the cell where the UE detected RLF, or the identification information of the target cell where the handover failed;

[0243] 2) connectionFailureType: connection failure type, such as RLF or HOF;

[0244] 3) previousPCellId: the source cell identification information from which the UE last received a handover command.

[0245] 4) reestablishmentCellId: the cell identification information for initiating reestablishment after a connection failure;

[0246] 5) timeConnFailure: The time from the last receipt of the HO command to the connection failure;

[0247] 6) timeSinceFailure: The length of time from when the connection fails to when the connection fails. Generally refers to the time from when the connection fails to when the RLF-report is reported.

[0248] 7) rlf-Cause: The reason for radio link failure or handover failure, such as T310 timer timeout, T312 timer timeout, random access problem, beam failure recovery failure, LBT failure, excessive RLC retransmissions, etc.

[0249] Taking the T310 timer as an example, the UE's RRC layer starts timer T310 when it receives a number of consecutive downlink out-of-sync indications (N310) reported from the UE's physical layer. During the execution of timer T310, if the UE detects radio link recovery (i.e., it receives a number of consecutive downlink in-sync indications (N311) reported from the UE's physical layer) or receives / executes an RRC reconfiguration message with synchronization capabilities, timer T310 stops. Otherwise, the timer expires, at which point RRC reestablishment is initiated.

[0250] If the running time of timer T310 / T312 reaches specific threshold A, the UE considers the radio link to have failed. If the running time of timer T304 reaches specific threshold B, the UE considers the handover to have failed. Therefore, if the running time threshold of T304 / T310 / T312, which triggers the UE to record the SHR, is less than or equal to specific threshold C (failure threshold), and greater than or equal to specific threshold D, the UE considers a potential problem. Here, the value of specific threshold A is greater than the value of specific threshold B, and the value of specific threshold C is greater than the value of specific threshold D.

[0251] The definitions of the three timers T304 / T310 / T312 are as follows:

[0252] Timer T304: The duration of timer T304 indicates the duration from the time the terminal device receives the RRC reconfiguration message to the time it successfully completes random access to the target network device. The terminal device starts timer T304 when it receives the RRC reconfiguration message and stops the timer when random access is completed.

[0253] Timer T310: Also referred to as the first timer in the embodiments of the present application. The duration of timer T310 indicates the duration that the terminal device detects physical layer problems with the source network device. This problem is typically caused by the number of consecutive downlink out-of-sync indications exceeding a certain threshold. After timer T310 is started, if the radio link recovers while timer T310 is running, timer T310 is stopped.

[0254] Timer T312: Also referred to as the second timer in the present embodiment. Timer T312 is started during the execution of timer T310. The execution duration of timer T312 indicates the duration between the time when the terminal device triggers a measurement report (typically) and the time when the terminal device and the source network device regain synchronization during the execution of timer T312.

[0255] Specifically, examples of the start time, stop time, and processing after expiration of the above three timers are shown in Table 2.

[0256] Table 2 Timer functions

[0257] If a connection failure occurs on the UE (e.g., radio link failure or handover failure), the UE will record an RLF report. If the UE fails to connect again, the UE will clear the previously recorded RLF report and record the latest RLF report. The RLF report reporting mechanism is delayed reporting. For example, the UE records the RLF report. When the UE accesses the network device, the network has a mechanism to request the UE to report the RLF report through a UE Information Request message. The UE sends the RLF report to the network device through a UE Information Response message, which is used by the network device to identify mobility process problems and optimize mobility parameters.

[0258] To mitigate RA failures caused by improper network device configuration, the UE typically records information from the RA process and generates a corresponding RA report. When the UE initiates random access, it records the RA report. Unlike an RLF report, which records connection failure information, the UE does not need to detect an RA failure before recording the RA report.

[0259] The RA report records the relevant parameters of the random access process for the UE, mainly including the random access cell identification information (the cell identification information of the cell group or the SpCell cell identification information of the cell group to which the UE sends the random access preamble), the reason for the random process (such as the need to access the cell, uplink desynchronization, request for system message, etc.), and an information element RA-InformationCommon indicating one or more items of information related to 2-step and / or 4-step random access.

[0260] RA-InformationCommon includes the following: frequency information, PRACH resource time-frequency domain information, subcarrier spacing, maximum number of msgA transmissions, downlink reference information number RSRP measured during 2-step / 4-step selection, random access attempt information including beam number and number of preambles sent on the beam, conflict detection indication, and indication information of whether the 4-step / 2-step RSRP threshold is reached, fallback indication information from 2-step to 4-step, amount of data to be transmitted for two-step random access, and one or more of the physical uplink shared channel PUSCH configuration information for two-step random access.

[0261] The current RLF report covers traditional handover, CHO, and DAPS mobility scenarios, recording information about radio link failure or handover failure in these scenarios. However, it does not support LTM scenarios. For example, in LTM scenarios, the UE currently does not provide feedback on handover success or radio link failure.

[0262] In view of this, an embodiment of the present application proposes a communication method that enables a UE to provide feedback to a network device regarding radio link failure. The following describes the communication method using a terminal device and a network device as the interaction entities. As shown in FIG6 , the method includes the following steps:

[0263] S610, the network device sends first information to the terminal device, and correspondingly, the terminal device receives the first information.

[0264] The first information indicates that the terminal device switches to the target cell. For example, the first information indicates the index of the target cell. Alternatively, the first information indicates a predefined number of the target cell. For example, the predefined cell A is numbered 1, the predefined cell B is numbered 2, and the predefined cell C is numbered 3, then the first information indicates that number 1 indicates cell A.

[0265] It should be understood that the above-mentioned cell index and predefined cell number are merely examples for identifying cells and are not limiting. Other methods for identifying or distinguishing different cells should also fall within the scope of protection of this application.

[0266] The first information may be sent via a medium access control control element.

[0267] The target cell is one of at least one candidate cell. The configuration information of the at least one candidate cell may be pre-received by the terminal device. For example, the network device sends the configuration information of the at least one candidate cell to the terminal device, and the terminal device receives the configuration information. Optionally, the terminal device may also store the configuration information.

[0268] S620, the terminal device records the first report.

[0269] The first report is used to indicate the reason for the connection failure during the terminal device's execution of layer 1 or layer 2 mobility.

[0270] The connection failure includes two situations. The first report is described below corresponding to different situations.

[0271] Case 1: The wireless link between the terminal device and the source cell fails.

[0272] The first report indicates a reason for the wireless link failure, where the reason for the wireless link failure includes at least one of the following:

[0273] The first timer expires, that is, the running length of the first timer is greater than or equal to the first threshold value, wherein the running length of the first timer is the time from when the terminal device detects a physical layer desynchronization problem with the source network device to when the terminal device receives the first information;

[0274] The second timer expires, that is, the running length of the second timer is greater than or equal to the second threshold value, wherein the running length of the second timer is the length of time from the terminal device triggering the measurement report to the terminal device receiving the first information during the running of the first timer.

[0275] The first timer can refer to the above description of the T310 timer. The second timer can refer to the above description of the T312 timer. No further details will be given here. It should be noted that the first timer can be an enhancement based on the T310 timer, or it can be a newly designed timer that is different from the T310 timer. When the first timer is a newly designed timer that is different from the T310 timer, and the first timer is configured, the terminal device can release or delete or deactivate (save the T310 / T312 timer configuration, but do not run the timer) the configured T310 timer. The second timer is the same as the T320 timer and will not be described in detail.

[0276] The reasons for wireless link failure also include at least one of random access failure, beam failure recovery failure, listen-before-speak failure, and the number of wireless link layer control protocol retransmissions being greater than or equal to the fifth threshold value.

[0277] The first threshold, the second threshold and the fifth threshold may be predefined or configured for the terminal device by the network side.

[0278] It should be understood that the number of radio link layer control protocol retransmissions can also be replaced by other parameters, such as the total number of radio link layer control protocol transmissions, etc., all of which should be within the scope of protection of this application. For example, the number of RRC retransmissions is 3, which has the same meaning as the total number of RRC transmissions is 4.

[0279] The first report further indicates information about the first candidate cell, where the information about the first candidate cell includes at least one of the following: identification information of the first candidate cell, whether a random access response (RAR) is configured for the first candidate cell, or Layer 1 reporting configuration information corresponding to the first candidate cell. The first candidate cell is one or more of the at least one candidate cell. In other words, the first report indicates information about one or more of the at least one candidate cell.

[0280] The first report also indicates early TA information, which includes whether the terminal device has performed early TA in the target cell, the candidate cell for performing early TA, the number of physical downlink control link instructions for performing early TA to the candidate cell, physical random access channel resource information, synchronization signal block beam identifier or preamble code identifier.

[0281] The first report also indicates the source cell radio link failure information, which includes at least one of the layer 1 measurement result or layer 3 measurement result available when the detection failure occurs, the connection failure type being radio link failure, the cell where the radio link fails being the source cell, or the time from when the terminal device receives the configuration information of at least one candidate cell to when the terminal device detects the source cell radio link failure.

[0282] Case 2: The terminal device fails to switch or fails to switch within the first time period after a successful switch.

[0283] The first period of time may be predefined or configured.

[0284] In other words, the terminal device fails to switch or fails immediately after switching successfully. In this case, the reason for the connection failure is the switching failure.

[0285] The first report may indicate information of the first candidate cell and / or early advance timing information. For details, please refer to the description in Case 1.

[0286] The first report may also indicate at least one of the following:

[0287] The identifier of the target cell,

[0288] Whether the target cell has an available advance timing value,

[0289] The access type used by the terminal device to access the target cell, such as whether the access type is random access-free or random access, or whether the access type is random access-free or random access-free.

[0290] Beam indication information for uplink or downlink data transmission in the target cell,

[0291] an identifier of a first cell, wherein the first cell is a cell having an available advance timing value, and the first cell belongs to one or more of the at least one candidate cell;

[0292] First time information, the first time information includes at least one of the following:

[0293] The time from when the terminal device receives the configuration information of at least one candidate cell to when the terminal device receives the first information or when the terminal device initiates cell switching,

[0294] The time from when the terminal device receives the first physical downlink control channel PDCCH instruction to when the terminal device receives the first information or when the terminal device initiates cell switching,

[0295] The time duration from when the terminal device receives the last physical downlink control channel PDCCH instruction to when the terminal device receives the first information or when the terminal device initiates cell switching.

[0296] Optionally, the first report further indicates at least one of the following:

[0297] The type of connection failure, such as handover failure or wireless link failure.

[0298] The reason for the switch failure includes at least one of the following:

[0299] The third timer expires, that is, the running length of the third timer is greater than or equal to the third threshold value, and the running length of the third timer is the length of time from the terminal device receiving the first information to the terminal device completing random access or the terminal device sending the first uplink data,

[0300] The fourth timer expires, that is, the running length of the fourth counter is greater than or equal to the fourth threshold value, and the running length of the fourth timer is the time from the terminal receiving or executing the RRC reconfiguration message with synchronization function to the terminal device completing random access or the terminal device receiving the physical control channel transmission after the first uplink transmission when no random access is required; among them, the RRC reconfiguration message with synchronization function is an RRC reconfiguration message containing reconfigurationWithSync.

[0301] The third threshold value and / or the fourth threshold value may be predefined or configured.

[0302] The handover type of the last handover was layer 1 or layer 2 mobility handover.

[0303] The cell where the connection failure is detected is the target cell.

[0304] The second time information includes the time from the time the terminal device receives the previous layer 1 or layer 2 mobility command to the time when the cell switching failure occurs, or the time when the terminal device sends the first report; or, the second time information includes the time from the time the terminal device initiates the cell switching to the time when the cell switching failure occurs, or the time when the terminal device sends the first report.

[0305] The running time of the third timer.

[0306] The running time of the fourth timer.

[0307] The layer 1 measurement result or layer 3 measurement result available when the detection fails.

[0308] It should be understood that other methods that can determine whether the timer running time has expired should be within the scope of protection of this application, such as other multiplication, subtraction, addition or logarithm calculations or processing that can compare size relationships.

[0309] The cell handover process information based on random access includes information about a two-step random access process and / or a four-step random access process. For details, please refer to the above description of the two-step random access process and / or the four-step random access process.

[0310] It should be understood that there are three ways to indicate "yes or not" involved in this application, one way is to indicate yes (true), another way is to indicate no (false), and another way is to indicate yes or no (true or false). For example, whether the terminal device has performed early advance timing in the target cell, one way is to indicate that the terminal device has performed early advance timing in the target cell only when the terminal device has performed early advance timing in the target cell. Another way is to indicate that the terminal device has not performed early advance timing in the target cell only when the terminal device has not performed early advance timing in the target cell. Yet another way is to indicate that the terminal device has performed early advance timing in the target cell, and to indicate that the terminal device has not performed early advance timing in the target cell. Other contents indicating "yes or not" in this article can refer to the explanation here, such as "whether the neighboring area belongs to one or more candidate cells".

[0311] In addition, it should be noted that the indication of "A or B" in this application may mean indicating A or B, or indicating A, or indicating whether it is A, or indicating B, or indicating whether it is B. For example, indicating the access type of a terminal device may mean indicating random access-free or random access. It may also mean indicating random access-free. It may also mean indicating whether it is random access-free. It may also mean indicating random access. It may also mean indicating whether it is random access. "Not random access" can be understood as "is random access-free".

[0312] S630: The terminal device sends a first report to the network device, and correspondingly, the network device receives the first report.

[0313] Optionally, the method may further include:

[0314] S640: The network device adjusts the mobility parameters according to the first report.

[0315] For example, the network device analyzes the first report and optimizes the LTM process and related parameters accordingly, such as indicating a more reasonable target cell for the terminal device to prevent the terminal device from switching to an unreasonable cell. Alternatively, the network device may instruct the terminal device to perform a cell switch at a more appropriate time to prevent the terminal device from performing the switch too early or too late, thereby reducing the probability of handover failure or radio link failure and reducing the impact of data transmission interruption time on user experience.

[0316] In this method, when a connection failure occurs in the LTM scenario, the terminal device can report the cause of the connection failure to the network device through a first report. Furthermore, other relevant information of the mobility process can be reported in the first report to facilitate the network device to optimize relevant parameters and reduce the interruption delay caused by the connection failure.

[0317] To facilitate a clear understanding of the solution of the present application, two process examples applicable to the above technical solution are given below, taking gNB-CU as an example of a network device and UE as an example of a terminal device.

[0318] One implementation is shown in FIG7 , which is the implementation process of Case 1. The process includes the following steps:

[0319] S710: The CU obtains RRC configuration information of the candidate cell.

[0320] Optionally, the gNB-CU decides to initiate an LTM (L1 / L2 Triggered Mobility) procedure based on a measurement report containing L3 measurement results received from the UE.

[0321] It should be noted that the candidate cell can be a cell managed by the source CU or a cell managed by another CU. In these two cases, the information sent and received by the CU is different. Specifically,

[0322] In the inter-CU case, that is, the candidate cell is a cell managed by another CU, as shown in (a) of Figure 8 , the source CU (CU1) sends a handover request message to the candidate CU (CU2), indicating the candidate cell. For example, the message carries the cell identifier of the candidate cell. The candidate CU (CU2) indicates the candidate cell to the candidate DUs it manages (such as DU2 and DU3). If the candidate DU accepts the request, it sends the low-layer RRC configuration of the candidate cell to the candidate CU to which the DU belongs, such as sending a handover request response, which carries the RRC configuration of the candidate cell.

[0323] If the candidate cell is not an intra-CU (intra-CU) cell, that is, the candidate cell is a cell managed by the CU, as shown in Figure 8(b), the CU indicates the candidate cell to the candidate DUs it manages (such as DU1, DU2, and DU3). For example, a handover request message is sent, which carries the identifier of the candidate cell. If the candidate DU accepts the request, it sends the low-layer RRC configuration information of the candidate target cell to the CU, such as a handover request response, which carries the RRC configuration of the candidate cell.

[0324] The candidate cell may be the at least one candidate cell mentioned above.

[0325] S720, the CU sends an RRC reconfiguration message to the UE via the DU, and correspondingly, the UE receives the RRC reconfiguration message.

[0326] The RRC reconfiguration message includes L1 / L2 mobility configuration information. The L1 / L2 mobility configuration information may include configuration information of one or more candidate cells. The L1 / L2 mobility configuration information may also include whether the candidate cell is configured with RAR. The L1 / L2 mobility configuration information also includes L1 measurement control information.

[0327] In order to reduce the data interruption time between the UE and the source cell due to the CFRA between the UE and the target (candidate) cell, LTM supports the UE to perform early uplink synchronization with the candidate cell. After the UE sends a preamble to the candidate cell, the UE receives or does not receive the RAR from the source cell. Whether the UE receives the RAR is configured by the network side. For example, the network device indicates to the UE whether each candidate cell in one or more candidate cells is configured with RAR. If the candidate cell is not configured with RAR, when the LTM command (i.e., an example of the first information) indicates that the candidate cell is the target cell, the LTM command also indicates the TA value of the target cell.

[0328] The UE can record the RLF report, which can indicate information about the LTM candidate cell, such as cell identification information, whether the candidate cell is configured with RAR, and L1 reporting configuration information (such as the SSB set corresponding to the candidate cell RS). Among them, the L1 measurement result may not include beam identification information. The network side combines the L1 reporting configuration information and the L1 measurement result to obtain the beam-level L1 RSRP of the candidate cell.

[0329] Optionally, in S730, the UE performs early uplink synchronization and / or downlink synchronization with the candidate cell.

[0330] For example, before the UE receives the LTM command, the UE's service DU may trigger the UE to perform early TA acquisition of candidate cells. Specifically, the service DU indicates to the UE contention-free random access CFRA resources, such as SSB beam, PRACH resources and / or preamble identifier, in a PDCCH order. The service DU also indicates the ID of the candidate cell to the UE.

[0331] The UE sends a random access preamble to the candidate cell and performs a cell search to achieve early downlink synchronization with the candidate cell.

[0332] For example, the UE performs early uplink synchronization and / or downlink synchronization with the candidate cells DU2 and DU3.

[0333] The UE can record the RLF report, which can indicate one or more items of early TA-related information, such as whether the UE has performed early TA, the candidate cell for performing early TA, the number of PDCCH orders for the candidate cell, PRACH resource time-frequency domain information, SSB beam identification information, preamble identification information, etc.

[0334] One possible approach is to indicate the early TA related information in the RA report as described above.

[0335] S740: The UE sends the L1 measurement result to the DU, and correspondingly, the DU receives the L1 measurement result.

[0336] S750: DU decides to perform L1 / L2 inter-cell mobility.

[0337] S760: The UE detects that an RLF occurs in the source cell.

[0338] The UE can record the RLF report, where the RLF report indicates one or more of the following RLF information of the source cell: available L1 measurement results / available L3 measurement results when the detection fails; indication that the connection failure type is RLF; the failed cell is the source cell; the reason for the RLF (such as expiration of the first timer and / or second timer mentioned above); the time from the terminal device receiving the LTM candidate cell pre-configuration to detecting the RLF.

[0339] In particular, step S760 is performed before receiving the LTM command, that is, before receiving the LTM command sent by the DU to the UE, the UE detects that an RLF occurs in the source cell.

[0340] S770, the UE sends an RLF report to the CU via the DU, and correspondingly, the CU receives the RLF report.

[0341] It should be understood that the RLF report in this implementation can refer to the description in Case 1 above.

[0342] In this implementation, when a connection failure occurs in the source cell, the UE promptly reports the failure cause and related information to the network device, so that the network side can analyze the failure cause of the RLF in the source cell, thereby optimizing the mobility parameters and reducing the probability of the UE experiencing RLF in the source cell due to a late handover (cell switch).

[0343] One implementation is shown in FIG9 , which is the implementation process of Case 2. The process includes the following steps:

[0344] S910: The CU obtains RRC configuration information of the candidate cell.

[0345] S920. The CU sends an RRC reconfiguration message to the UE via the DU. Correspondingly, the UE receives the RRC reconfiguration message.

[0346] Optionally, in S930, the UE performs early uplink synchronization and / or downlink synchronization with the candidate cell.

[0347] S940: The UE sends the L1 measurement result to the DU, and correspondingly, the DU receives the L1 measurement result.

[0348] S950: DU decides to perform L1 / L2 inter-cell mobility.

[0349] Specifically, S910 to S950 may refer to the description of S710 to S750.

[0350] In particular, in S930, the cell performing early TA may be a target cell or a candidate cell performing early TA, and it may also be indicated among these candidate cells whether the candidate cell is a target cell.

[0351] S960: The DU sends an LTM command to the UE, and correspondingly, the UE receives the LTM command.

[0352] The LTM command includes the identification information of the target cell. In one possible manner, the LTM command may be sent to the UE via a MAC CE. In another possible manner, the LTM command may be other information from L1 / L2.

[0353] Optionally, before the DU sends the LTM command, the UE sends an L1 measurement result to the DU. The DU determines a target cell based on the L1 measurement result, sends an LTM command to the UE, and indicates the target cell through the LTM command.

[0354] It should be understood that the order of performing early uplink synchronization and early downlink synchronization on the UE and reporting the L1 measurement result by the UE in the embodiment of the present application is not limited.

[0355] The LTM command may further include the TA value of the target cell, and the LTM command may further include information about the beam used by the target cell for uplink / downlink data transmission.

[0356] The UE can perform a cell switch according to the LTM command. Specifically, the UE applies the configuration information of the target cell. If the UE obtains the TA value of the target cell (an available TA value), it performs a random access-free (RAHC-less) to access the target cell. Otherwise, it initiates a random access to the target cell.

[0357] The UE obtains the TA value of the target cell as follows:

[0358] Method 1: If the target cell is configured with RAR, the UE receives the TA value of the target cell through RAR before the LTM command. For example, the RAR can be sent to the UE by the current DU or from the target cell, without limitation.

[0359] Method 2: If the target cell is not configured with RAR, indicate the TA value of the target cell in the LTM command.

[0360] The UE may record an RLF report, which may indicate one or more items of information related to the LTM command:

[0361] Indicates the target cell identification information

[0362] Indicates whether the target cell has an available TA value, or indicates RACH-less or RACH-based access; it can also indicate whether only the target cell has an available TA value, or only indicates RACH-less access.

[0363] Beam indication information indicating the target cell for uplink / downlink data transmission;

[0364] Indicates the cell identification information with available TA value;

[0365] An item indicating the first time information (candidate cell configuration information / time from when the UE receives the first PDCCH order / time from when the UE receives the last PDCCH order to when the LTM command is issued / cell handover is initiated)

[0366] In a possible implementation, the above LTM command related information may also be indicated in the RA report.

[0367] S970 , the DU sends an LTM notification to the CU, and correspondingly, the CU receives the LTM notification.

[0368] The LTM notification is used to notify the CU of the initiation of the LTM command. Optionally, the LTM notification also includes identification information of the target cell.

[0369] S980: The UE fails to perform LTM cell handover, or an RLF occurs in the target cell soon after the cell handover is successful.

[0370] For example, the UE performs cell handover in a random access-free or random access-based manner. In other words, the types of cell handover include random access-free or random access-based.

[0371] In one possible implementation, the UE may detect the cell handover status based on the third timer and / or the fourth timer described above. The cell handover status includes a successful cell handover or a failed cell handover. When the cell handover fails, if it is a RACH-less access, the UE considers that the network side has not received the initial uplink data during the operation of the third timer, or the UE considers that the downlink physical control channel transmission has not been received after the first uplink transmission during the operation of the fourth timer; if it is a random access, the UE considers that the random access has failed (for example, the maximum number of preamble transmissions has been reached, the third timer has timed out, the fourth timer has timed out, etc.).

[0372] When the first timer expires, the UE may record a first report (such as an RLF report). The first report may indicate one or more items of cell access related information:

[0373] Indicates that the connection failure type is HOF / RLF;

[0374] Indicates that the last switch type is LTM;

[0375] The cell that failed is the target cell;

[0376] Second time information, the time when the last LTM command is received / cell handover is initiated and the time when a cell handover failure occurs / is reported;

[0377] The running time of the third timer,

[0378] The running time of the fourth timer,

[0379] Available L1 measurement results / available L3 measurement results when the detection fails;

[0380] Indicates whether the third timer has timed out;

[0381] Indicates whether the fourth timer has timed out;

[0382] The cell handover process information based on random access indicates that the information related to 2-step and / or 4-step random access is recorded, as described in the ra-InformationCommon information element above. Optionally, if the cell has been recorded in the early TA, the PRACH resource information is no longer recorded repeatedly.

[0383] In a possible implementation, the above cell switching process information based on random access may also be indicated in the RA report.

[0384] Optionally, in S990, the UE executes the LTM fast recovery process.

[0385] If the cell handover at S980 fails or soon after the radio link failure (RLF) in the target cell, the UE can use the LTM fast recovery procedure to access a candidate cell.

[0386] In one possible manner, the UE performs cell selection, and the selected cell is the candidate cell mentioned above. The UE applies the saved configuration information of the candidate cell to access the candidate cell in a random access or random access-free manner (same as the above cell switching process).

[0387] In another possible manner, if the cell selected by the UE is not a candidate cell, or the cell selected by the UE is not among the candidate cells configured on the network side, the UE initiates an RRC re-establishment procedure.

[0388] It should be understood that the UE successfully executing the LTM fast recovery process, that is, the UE successfully accessing the candidate cell through the LTM fast recovery process, can also be regarded as a scenario of successful LTM cell handover.

[0389] The UE performs the LTM fast recovery procedure, and the RLF report may include information related to the fast recovery procedure. The RLF report may include information about one or more candidate cells for fast recovery and / or the duration between the UE's handover failure and successful access to a candidate cell.

[0390] S9100, the UE sends an RLF report to the CU via the DU, and correspondingly, the CU receives the RLF report.

[0391] Specifically, regarding the contents of the RLF report, please refer to the description of Case 2 above and will not be repeated here.

[0392] In this implementation process, the UE can record relevant information about the UE's failure to perform cell handover in the LTM scenario or failure that occurs soon after the handover is successful, so that the network side can analyze the reasons for the failure to access the target cell or the failure in the target cell, thereby optimizing the corresponding mobility parameters and reducing the probability of premature handover or switching to the wrong cell.

[0393] It can be understood that some optional features in the various embodiments of the present application may not depend on other features in certain scenarios, and may also be combined with other features in certain scenarios, without limitation.

[0394] It can also be understood that the solutions in the various embodiments of the present application can be reasonably combined and used, and the explanations or descriptions of the various terms appearing in the embodiments can be referenced or explained with each other in the various embodiments, without limitation to this.

[0395] It can also be understood that in the above-mentioned various method embodiments, the methods and operations implemented by the communication device can also be implemented by components (such as chips or circuits) of the communication device.

[0396] Corresponding to the methods provided in the above method embodiments, embodiments of the present application also provide corresponding apparatuses, which include modules for executing the corresponding methods in the above method embodiments. The modules may be software, hardware, or a combination of software and hardware. It is understood that the technical features described in the above method embodiments are also applicable to the following apparatus embodiments.

[0397] FIG10 is a schematic block diagram of a communication device 1000 provided in an embodiment of the present application. The device 1000 includes a transceiver unit 1010. The transceiver unit 1010 can be used to implement corresponding communication functions. The transceiver unit 1010 can also be referred to as a communication interface or a communication unit.

[0398] Optionally, the apparatus 1000 further includes a processing unit 1020. The processing unit 1020 may be configured to perform information processing.

[0399] Optionally, the device 1000 also includes a storage unit, which can be used to store instructions and / or data. The processing unit 1020 can read the instructions and / or data in the storage unit so that the device implements the actions of the communication device in the aforementioned method embodiments.

[0400] In one design, the apparatus 1000 may be the terminal device in the aforementioned embodiment, or may be a component (such as a chip) of the terminal device. The apparatus 1000 may implement steps or processes corresponding to those performed by the terminal device in the above method embodiment, wherein the transceiver unit 1010 may be used to perform the transceiver-related operations of the terminal device in the above method embodiment, and the processing unit 1020 may be used to perform the processing-related operations of the terminal device in the above method embodiment.

[0401] In a possible implementation, the transceiver unit 1010 is configured to receive first information and may also be configured to send a first report.

[0402] In another possible implementation, the processing unit 1020 is configured to switch cells and may also be configured to record the first report.

[0403] The device 1000 can implement the steps or processes executed by the terminal device in the method embodiment according to the embodiment of the present application. The device 1000 may include a unit for executing the method executed by the terminal device in the embodiments shown in Figures 6 to 9.

[0404] In another design, the apparatus 1000 may be the network device in the aforementioned embodiment, or a component (e.g., a chip) of the network device. The apparatus 1000 may implement steps or processes corresponding to those performed by the network device in the above method embodiment, wherein the transceiver unit 1010 may be used to perform the transceiver-related operations of the network device in the above method embodiment, and the processing unit 1020 may be used to perform the processing-related operations of the network device in the above method embodiment.

[0405] In a possible implementation, the processing unit 1020 is configured to send the first information.

[0406] In another possible implementation, the transceiver unit 1010 is configured to receive a first report.

[0407] The device 1000 can implement the steps or processes executed by the network device in the method embodiment according to the embodiment of the present application. The device 1000 may include a unit for executing the method executed by the network device in the embodiments shown in Figures 6 to 9.

[0408] A more detailed description of the device 1000 can be directly obtained by referring to the relevant description in the above method embodiment, which will not be repeated here.

[0409] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0410] It should also be understood that the device 1000 here is embodied in the form of a functional unit. The term "unit" here may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combined logic circuit and / or other suitable components that support the described functions. In an optional example, those skilled in the art will understand that the device 1000 can be specifically a communication device (such as a terminal device, or a network device) in the above-mentioned embodiment, and can be used to execute the various processes and / or steps corresponding to the communication device in the above-mentioned method embodiments. To avoid repetition, they will not be described here.

[0411] The apparatus 1000 of each of the above-mentioned solutions has the function of implementing the corresponding steps performed by the communication device (such as a terminal device, or a network device) in the above-mentioned method. The functions can be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more modules corresponding to the above-mentioned functions; for example, the transceiver unit can be replaced by a transceiver (for example, the sending unit in the transceiver unit can be replaced by a transmitter, and the receiving unit in the transceiver unit can be replaced by a receiver), and other units, such as the processing unit, can be replaced by a processor to respectively perform the sending and receiving operations and related processing operations in each method embodiment.

[0412] In addition, the transceiver unit 1010 may also be a transceiver circuit (for example, may include a receiving circuit and a sending circuit), and the processing unit may be a processing circuit.

[0413] It should be noted that the apparatus in FIG10 may be the device in the aforementioned embodiment, or may be a chip or chip system, such as a system on chip (SoC). The transceiver unit may be an input / output circuit or a communication interface; the processing unit may be a processor, microprocessor, or integrated circuit integrated on the chip. This is not limited here.

[0414] Figure 11 is a schematic block diagram of a communication device 1100 provided in an embodiment of the present application. The device 1100 includes a processor 1110, which is coupled to a memory 1120. Optionally, the memory 1120 is further included to store computer programs or instructions and / or data. The processor 1110 is configured to execute the computer programs or instructions stored in the memory 1120, or read data stored in the memory 1120, to perform the methods described in the above method embodiments.

[0415] Optionally, there are one or more processors 1110 .

[0416] Optionally, there are one or more memories 1120 .

[0417] Optionally, the memory 1120 is integrated with the processor 1110 or provided separately.

[0418] Optionally, as shown in Figure 11 , the apparatus 1100 further includes a transceiver 1130, which is configured to receive and / or transmit signals. For example, the processor 1110 is configured to control the transceiver 1130 to receive and / or transmit signals.

[0419] As a solution, the device 1100 is used to implement the operations performed by the communication device in the above various method embodiments.

[0420] For example, the processor 1110 is configured to execute computer programs or instructions stored in the memory 1120 to implement relevant operations of the terminal device or network device in the above various method embodiments.

[0421] During implementation, each step of the above method can be completed by an integrated logic circuit of the hardware in the processor 1110 or by instructions in the form of software. The method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 1120, and the processor 1110 reads the information in the memory 1120 and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

[0422] It should be understood that in the embodiments of the present application, the processor may be one or more integrated circuits for executing relevant programs to perform the method embodiments of the present application.

[0423] A processor (e.g., processor 1110) may include one or more processors and be implemented as a combination of computing devices. The processor may include one or more of the following: a microprocessor, a microcontroller, a digital signal processor (DSP), a digital signal processing device (DSPD), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device (PLD), gating logic, transistor logic, discrete hardware circuits, processing circuits, or other suitable hardware, firmware, and / or a combination of hardware and software to perform the various functions described in this disclosure. The processor may be a general-purpose processor or a special-purpose processor. For example, processor 1110 may be a baseband processor or a central processing unit. A baseband processor may be used to process communication protocols and communication data. A central processing unit may be used to enable the device to execute software programs and process data in the software programs. In addition, a portion of the processor may also include non-volatile random access memory. For example, the processor may also store information about the device type.

[0424] In this application, the term "program" is used broadly to refer to software. Non-limiting examples of software include program code, program, subroutine, instruction, instruction set, code, code segment, software module, application, or software application. The program can be executed in a processor and / or computer to cause the device to perform the various functions and / or processes described in this application.

[0425] The memory (e.g., memory 1120) can store data required by the processor (e.g., processor 1110) when executing software. The memory can be implemented using any suitable storage technology. For example, the memory can be any available storage medium that can be accessed by the processor and / or computer. Non-limiting examples of storage media include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM), static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM), removable media, optical disk storage, magnetic disk storage media, magnetic storage devices, flash memory, registers, state memory, remotely mounted storage, local or remote memory components, or any other medium capable of carrying or storing software, data, or information and accessible by a processor / computer. It should be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0426] The memory (e.g., memory 1120) and the processor (e.g., processor 1110) may be provided separately or integrated together. The memory may be used to connect to the processor so that the processor can read information from the memory and store and / or write information to the memory. The memory may be integrated into the processor. The memory and the processor may be provided in an integrated circuit (e.g., the integrated circuit may be provided in a UE or other network node).

[0427] 12 is a schematic block diagram of a chip system 1200 provided in an embodiment of the present application. The chip system 1200 (or also referred to as a processing system) includes a logic circuit 1210 and an input / output interface 1220 .

[0428] Logic circuit 1210 may be a processing circuit within chip system 1200. Logic circuit 1210 may be coupled to a storage unit and invoke instructions within the storage unit, enabling chip system 1200 to implement the methods and functions of various embodiments of the present application. Input / output interface 1220 may be an input / output circuit within chip system 1200, outputting information processed by chip system 1200 or inputting data or signaling information to be processed into chip system 1200 for processing.

[0429] As a solution, the chip system 1200 is used to implement the operations performed by the communication device in the above various method embodiments.

[0430] For example, the logic circuit 1210 is used to implement the processing-related operations performed by the terminal device in the above method embodiments, such as the processing-related operations performed by the terminal device in the embodiment shown in Figure 3; the input / output interface 1220 is used to implement the sending and / or receiving-related operations performed by the terminal device in the above method embodiments, such as the sending and / or receiving-related operations performed by the terminal device in the embodiment shown in Figure 3.

[0431] For another example, the logic circuit 1210 is used to implement the processing-related operations performed by the network device in the above method embodiments, such as the processing-related operations performed by the network device in the embodiment shown in Figure 3; the input / output interface 1220 is used to implement the sending and / or receiving-related operations performed by the network device in the above method embodiments, such as the sending and / or receiving-related operations performed by the network device in the embodiment shown in Figure 3.

[0432] An embodiment of the present application further provides a computer-readable storage medium storing computer instructions for implementing the methods executed by a communication device (such as a terminal device or a network device) in the above-mentioned method embodiments.

[0433] An embodiment of the present application further provides a computer program product comprising instructions, which, when executed by a computer, implement the methods performed by a communication device (such as a terminal device or a network device) in the above-mentioned method embodiments.

[0434] An embodiment of the present application also provides a communication system, which includes the terminal device and network device in the above embodiments.

[0435] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0436] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the above-mentioned units is only a logical function division. There may 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. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0437] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to implement the solutions provided in this application.

[0438] In addition, each functional unit in each embodiment of the present application may be integrated into one unit, each unit may exist physically separately, or two or more units may be integrated into one unit.

[0439] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0440] When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center to another website, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). About computer-readable storage media, reference can be made to the above description.

[0441] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: include: receiving first information, the first information indicating that a terminal device switches from a source cell to a target cell, the target cell belongs to at least one candidate cell, the configuration information of the target cell belongs to the configuration information of the at least one candidate cell received by the terminal device, and the first information is sent via a media access control control element; Recording a first report, the first report being used to indicate a reason for a connection failure during a layer 1 or layer 2 mobility process performed by the terminal device; The first report is sent.

2. The method according to claim 1, characterized in that The first report also indicates information of a first candidate cell, the information of the first candidate cell including identification information of the first candidate cell, whether the first candidate cell is configured with a random access response RAR, or at least one of layer 1 reporting configuration information corresponding to the first candidate cell, and the first candidate cell is one or more of the at least one candidate cell.

3. The method according to claim 1 or 2, characterized in that: The first report also indicates early advance timing information, which includes whether the terminal device has executed early advance timing in the target cell, the candidate cell for executing the early advance timing, the number of physical downlink control link instructions indicating the execution of the early advance timing to the candidate cell, physical random access channel resource information, and at least one of a synchronization signal block beam identifier or a preamble code identifier.

4. The method according to any one of claims 1 to 3, characterized in that The connection failure includes a radio link failure of the source cell, The reason for the wireless link failure includes at least one of the following: The running time of the first timer is greater than or equal to the first threshold value, wherein the running time of the first timer is the time from when the terminal device detects a physical layer desynchronization problem with the source network device to when the terminal device receives the first information; The running time of the second timer is greater than or equal to the second threshold value, wherein the running time of the second timer is the time duration from when the terminal device triggers the sending of the measurement report to when the terminal device receives the first information during the running of the first timer.

5. The method according to claim 4, characterized in that The reasons for the wireless link failure also include at least one of random access failure, beam failure recovery failure, listen-before-talk failure, and the number of wireless link layer control protocol retransmissions being greater than or equal to a fifth threshold value.

6. The method according to claim 4 or 5, characterized in that: The first report also indicates the radio link failure information of the source cell, and the radio link failure information of the source cell includes at least one of the layer 1 measurement result or layer 3 measurement result available when the detection failure occurs, the connection failure type is a radio link failure, the cell with the radio link failure is the source cell, or the time from the terminal device receiving the configuration information of the at least one candidate cell to the terminal device detecting the radio link failure of the source cell.

7. The method according to any one of claims 1 to 3, characterized in that The connection failure includes a switching failure of the terminal device or a switching failure within a first time period after a successful switching, and the first time period is predefined or configured.

8. The method according to claim 7, characterized in that The first report also indicates at least one of the following: the identifier of the target cell, Whether the target cell has an available advance timing value, an access type used by the terminal device to access the target cell, the access type being random access-free or random access, or the access type being random access-free, The target cell is used for uplink or downlink data transmission beam indication information, an identifier of a first cell, the first cell being a cell having an available advance timing value, the first cell belonging to one or more of the at least one candidate cell, First time information, the first time information includes at least one of the following: The time from when the terminal device receives the configuration information of the at least one candidate cell to when the terminal device receives the first information or the time when the terminal device initiates cell switching, The time from when the terminal device receives the first physical downlink control channel PDCCH instruction to when the terminal device receives the first information or the time when the terminal device initiates a cell handover, The time duration from when the terminal device receives the last physical downlink control channel PDCCH instruction to when the terminal device receives the first information or when the terminal device initiates cell switching.

9. The method according to claim 7 or 8, characterized in that: The first report also indicates at least one of the following: The type of connection failure, where the type of connection failure is a handover failure or a wireless link failure; The reason for the handover failure, wherein the reason for the handover failure includes at least one of the following: The running time of the third timer is greater than or equal to the third threshold value, The running time of the third timer is the time from when the terminal device receives the first information to when the terminal device completes random access or sends the first uplink data; The running length of the fourth counter is greater than or equal to the fourth threshold value, and the running length of the fourth timer is the duration from the terminal receiving or executing the RRC reconfiguration message with a synchronization function to the terminal device completing random access or the terminal device receiving the physical control channel transmission after the first uplink transmission when random access is free; The handover type of the last handover was layer 1 or layer 2 mobility handover; The cell where the connection failure occurs is detected to be the target cell; second time information, the second time information including the time from when the terminal device receives the last layer 1 or layer 2 mobility command to when the cell handover failure occurs, or the time from when the terminal device sends the first report, Alternatively, the second time information includes the duration from when the terminal device initiates a cell handover to when a cell handover failure occurs, or the duration from when the terminal device sends the first report; the running time of the third timer; the running time of the fourth timer; The layer 1 measurement results or layer 3 measurement results available when the detection fails; The cell switching process information based on random access includes information of a two-step random access process and / or a four-step random access process.

10. A communication method, characterized in that: include: Sending first information, where the first information indicates that the terminal device switches from a source cell to a target cell, where the target cell belongs to at least one candidate cell, where the configuration information of the target cell belongs to the configuration information of the at least one candidate cell received by the terminal device, and where the first information is sent via a media access control control element; A first report is received, where the first report is used to indicate a reason for a connection failure during a layer 1 or layer 2 mobility process performed by the terminal device.

11. The method according to claim 10, characterized in that The first report also indicates information of a first candidate cell, the information of the first candidate cell including identification information of the first candidate cell, whether the first candidate cell is configured with a random access response RAR, or at least one of layer 1 reporting configuration information corresponding to the first candidate cell, and the first candidate cell is one or more of the at least one candidate cell.

12. The method according to claim 10 or 11, characterized in that: The first report also indicates early advance timing information, which includes whether the terminal device has executed early advance timing in the target cell, the candidate cell for executing the early advance timing, the number of physical downlink control channel PDCCH instructions indicating the execution of the early advance timing to the candidate cell, physical random access channel resource information, synchronization signal block beam identifier or at least one of the preamble code identifier.

13. The method according to any one of claims 10 to 12, characterized in that The connection failure includes a radio link failure of the source cell, The reason for the wireless link failure includes at least one of the following: The running time of the first timer is greater than or equal to the first threshold value, wherein the running time of the first timer is the time from when the terminal device detects a physical layer desynchronization problem with the source network device to when the terminal device receives the first information; The running time of the second timer is greater than or equal to the second threshold value, wherein the running time of the second timer is the time duration from when the terminal device triggers the sending of the measurement report to when the terminal device receives the first information during the running of the first timer.

14. The method according to claim 13, characterized in that The reasons for the wireless link failure also include at least one of random access failure, beam failure recovery failure, listen-before-talk failure, and the number of wireless link layer control protocol retransmissions being greater than or equal to a fifth threshold value.

15. The method according to claim 13 or 14, characterized in that The first report also indicates the radio link failure information of the source cell, and the radio link failure information of the source cell includes at least one of the layer 1 measurement result or layer 3 measurement result available when the detection failure occurs, the connection failure type is a radio link failure, the cell with the radio link failure is the source cell, or the time from the terminal device receiving the configuration information of the at least one candidate cell to the terminal device detecting the radio link failure of the source cell.

16. The method according to any one of claims 10 to 12, characterized in that The connection failure includes a switching failure of the terminal device or a switching failure within a first time period after a successful switching, and the first time period is predefined or configured.

17. The method according to claim 16, characterized in that The first report also indicates at least one of the following: an identifier of the target cell, Whether the target cell has an available advance timing value, an access type used by the terminal device to access the target cell, the access type being random access-free or random access, or the access type being random access-free, The target cell is used for uplink or downlink data transmission beam indication information, an identifier of a first cell, the first cell being a cell having an available advance timing value, the first cell belonging to one or more of the at least one candidate cell, First time information, the first time information includes at least one of the following: The time from when the terminal device receives the configuration information of the at least one candidate cell to when the terminal device receives the first information or the time when the terminal device initiates cell switching, The time from when the terminal device receives the first physical downlink control channel PDCCH instruction to when the terminal device receives the first information or the time when the terminal device initiates a cell handover, The time duration from when the terminal device receives the last physical downlink control channel PDCCH instruction to when the terminal device receives the first information or when the terminal device initiates cell switching.

18. The method according to claim 16 or 17, characterized in that The first report also indicates at least one of the following: The type of connection failure, where the type of connection failure is a handover failure or a wireless link failure; The reason for the handover failure, wherein the reason for the handover failure includes at least one of the following: The running time of the third timer is greater than or equal to the third threshold value, The running time of the third timer is the time from when the terminal device receives the first information to when the terminal device completes random access or sends the first uplink data; The running length of the fourth counter is greater than or equal to the fourth threshold value, and the running length of the fourth timer is the duration from the terminal receiving or executing the RRC reconfiguration message with a synchronization function to the terminal device completing random access or the terminal device receiving the physical control channel transmission after the first uplink transmission when random access is free; The handover type of the last handover was layer 1 or layer 2 mobility handover; The cell where the connection failure occurs is detected to be the target cell; second time information, the second time information including the time from when the terminal device receives the last layer 1 or layer 2 mobility command to when the cell handover failure occurs, or the time from when the terminal device sends the first report, Alternatively, the second time information includes the duration from when the terminal device initiates a cell handover to when a cell handover failure occurs, or the duration from when the terminal device sends the first report; the running time of the third timer; the running time of the fourth timer; The layer 1 measurement results or layer 3 measurement results available when the detection fails; The cell switching process information based on random access includes information of a two-step random access process and / or a four-step random access process.

19. A communication device, characterized in that: Comprising modules for executing the method as claimed in any one of claims 1 to 9.

20. A communication device, characterized in that: Comprising means for performing the method as claimed in any one of claims 10 to 18.

21. A communication system, characterized in that: Comprising the communication device as claimed in claim 19 and claim 20.

22. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program or instruction, and when the computer program or instruction is executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 18.

23. A computer program product, characterized in that The computer program product comprises instructions for performing the method of any one of claims 1 to 18.

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