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EP-3952441-B1 - CELL CONNECTION FAILURE PROCESSING METHOD AND TERMINAL DEVICE

EP3952441B1EP 3952441 B1EP3952441 B1EP 3952441B1EP-3952441-B1

Inventors

  • WU, Yumin

Dates

Publication Date
20260506
Application Date
20200323

Claims (15)

  1. A method for handling cell connection failure, performed by a terminal device and comprising: determining (101) whether connecting to a target serving cell has failed; and performing (103) connection failure handling based on serving cell related information in a case that connecting to the target serving cell has failed, wherein the serving cell related information comprises at least one of the number of cells and a cell type; wherein the determining (101) whether connecting to a target serving cell has failed comprises: increasing a first count value by 1 in a case that an uplink transmission state on the target serving cell is a first preset state; and in a case that the first count value is greater than or equal to a first count threshold, or after the first count value is greater than or equal to the first count threshold and an uplink transmission failure timer expires, determining that connecting to the target serving cell has failed; wherein the method further comprises: resetting the first count value in a case that an uplink transmission state on the target serving cell is a second preset state, and increasing the first count value by 1 in a case that an uplink transmission state on the target serving cell is the first preset state; wherein the first preset state comprises: within a second preset time window, the number of uplink transmission failures on the target serving cell meets a first condition; and the second preset state comprises: within a second preset time window, the number of successful uplink transmissions on the target serving cell meets a second condition; wherein the failed uplink transmission on the target serving cell is caused by channel occupation.
  2. The method according to claim 1, wherein the determining (101) whether connecting to a target serving cell has failed comprises: determining the number of uplink transmission failures on the target serving cell within a first preset time window; and determining, based on the number of uplink transmission failures, whether connecting to the target serving cell has failed.
  3. The method according to claim 2, wherein the determining, based on the number of uplink transmission failures, whether connecting to the target serving cell has failed comprises: determining that connecting to the target serving cell has failed in a case that the number of uplink transmission failures is greater than or equal to a value of threshold regarding the number of failures; or, wherein the determining, based on the number of uplink transmission failures, whether connecting to the target serving cell has failed comprises: determining an uplink transmission failure probability based on the number of uplink transmission failures; and in a case that the uplink transmission failure probability is greater than or equal to a failure probability threshold, determining that connecting to the target serving cell has failed.
  4. The method according to claim 1, further comprising: after the first count value is greater than or equal to the first count threshold and before the uplink transmission failure timer expires, performing at least one of operations of resetting the first count value or stopping the uplink transmission failure timer, in a case that a second count value used when the uplink transmission state on the target serving cell is a second preset state is greater than or equal to a second count threshold.
  5. The method according to claim 4, wherein the second count value is the total number of consecutive times that the uplink transmission state on the target serving cell is the second preset state.
  6. The method according to claim 1, wherein in a case that the serving cell related information is the cell type, the performing connection failure handling based on serving cell related information comprises at least one of the following: triggering a connection re-establishment procedure in a case that the target serving cell is a cell in a master cell group and that the terminal device has failed to connect to each cell in the mater cell group, or that the target serving cell is a primary cell; and reporting information related to the failure in connecting to the target serving cell, in a case that the target serving cell is a cell in a secondary cell group and that the terminal device has failed to connect to each cell in the secondary cell group, or that the target serving cell is the primary cell in the master cell group, or that the target serving cell is the primary secondary cell in the secondary cell group, or that the target serving cell is a secondary cell in the master cell group, or that the target serving cell is a secondary cell in the secondary cell group.
  7. The method according to claim 6, wherein the triggering a connection re-establishment procedure comprises: determining candidate frequencies, wherein the candidate frequencies do not comprise a frequency corresponding to the target serving cell, or the candidate frequencies do not comprise a frequency corresponding to the target serving cell for a preset time length; and triggering a connection re-establishment procedure based on the candidate frequencies.
  8. The method according to claim 7, wherein in the triggering a connection re-establishment procedure or after the triggering a connection re-establishment procedure, the method further comprises: reporting information related to the failure in connecting to the target serving cell.
  9. The method according to claim 8, wherein the information related to the failure in connecting to the target serving cell comprises at least one of the following: failure type indication information of the cell connection failure; or channel measurement information, wherein the channel measurement information comprises at least one of a received signal strength indicator, a channel occupancy ratio, and a channel busy ratio.
  10. The method according to claim 1, wherein in a case that the serving cell related information is the number of cells, the performing connection failure handling based on serving cell related information comprises: triggering a connection re-establishment procedure in a case that the number of cells is 1.
  11. The method according to claim 4, wherein, the first preset state further comprises: within the second preset time window, the number of uplink transmissions on the target serving cell is less than or equal to a number of uplink transmissions threshold; and the second preset state further comprises at least one of the following: within the second preset time window, the number of uplink transmissions on the target serving cell is less than or equal to a number of uplink transmissions threshold.
  12. A terminal device, comprising: a determining module (301), configured to determine whether connecting to a target serving cell has failed; and a handling module (303), configured to: in a case that connecting to the target serving cell has failed, perform connection failure handling based on serving cell related information, wherein the serving cell related information comprises at least one of the number of cells and a cell type; wherein the terminal device further comprises: a control module, configured to increase a first count value by 1 in a case that an uplink transmission state on the target serving cell is a first preset state; and the determining module is specifically configured to: determine that connecting to the target serving cell has failed, in a case that the first count value is greater than or equal to a first count threshold, or after the first count value is greater than or equal to the first count threshold and an uplink transmission failure timer expires; wherein the control module is configured to: reset the first count value in a case that an uplink transmission state on the target serving cell is a second preset state, and increase the first count value by 1 in a case that an uplink transmission state on the target serving cell is the first preset state; wherein the first preset state comprises: within a second preset time window, the number of uplink transmission failures on the target serving cell meets a first condition; and the second preset state comprises: within a second preset time window, the number of successful uplink transmissions on the target serving cell meets a second condition; wherein the failed uplink transmission on the target serving cell is caused by channel occupation.
  13. The terminal device according to claim 12, further comprising: an execution module, configured to, after the first count value is greater than or equal to the first count threshold and before the uplink transmission failure timer expires, perform at least one of operations of resetting the first count value or stopping the uplink transmission failure timer, in a case that a second count value used when the uplink transmission state on the target serving cell is a second preset state is greater than or equal to a second count threshold.
  14. The terminal device according to claim 13, wherein in a case that the serving cell related information is the cell type, the handling module is specifically configured to perform one of the following: triggering a connection re-establishment procedure in a case that the target serving cell is a cell in a master cell group and that the terminal device has failed to connect to each cell in the mater cell group, or that the target serving cell is a primary cell; and reporting information related to the failure in connecting to the target serving cell, in a case that the target serving cell is a cell in a secondary cell group and that the terminal device has failed to connect to each cell in the secondary cell group, or that the target serving cell is the primary cell in the master cell group, or that the target serving cell is the primary secondary cell in the secondary cell group, or that the target serving cell is a secondary cell in the master cell group, or that the target serving cell is a secondary cell in the secondary cell group.
  15. A computer-readable storage medium, wherein the computer-readable storage medium stores a program, and when the program is executed by a processor comprised in a terminal device, the terminal device is caused to perform the steps of the method according to any one of claims 1 to 11.

Description

TECHNICAL FIELD This disclosure relates to the field of communications technologies, and in particular, to methods for handling cell connection failure, a terminal device, and a network-side device. BACKGROUND At present, in new radio (New Radio, NR) mobile communications systems (NR system for short), unlicensed bands are shared bands. If an unlicensed band is used to transmit data, a transmitting end of the data needs to comply with rules for use of the unlicensed band, that is, the transmitting end needs to monitor, before transmitting data, whether the unlicensed band is occupied (or in a free state). If the unlicensed band is not occupied (or in a free state), the transmitting end can use the unlicensed band to transmit data; or if the unlicensed band is occupied (or in a busy state), that is, the transmitting end fails in listen before talk (Listen-Before-Talk, LBT), the transmitting end cannot use the unlicensed band to transmit data, to be specific, the transmitting end fails to connect to a cell, which may affect reliability of data transmission. Therefore, how to detect and specifically handle a cell connection failure to autonomously recover the connection and improve reliability of data transmission has become an urgent technical problem to be resolved. WO2019/031796A1 provides a method for handling pre-configured UL resources based on LBT procedure, which includes: receiving information for UL resource configuration from a network, in a state that the UE is configured with at least one serving cell operating in an unlicensed spectrum; performing LBT operation for transmission of uplink data by using the UL resource, wherein the UE starts counting a number of failures of the LBT operation once the UE is not allowed to use the UL resource for transmission of uplink data during the LBT operation, and when the number of failures of the LBT operation reaches to the maximum number of LBT failure, stopping using the UL resource. SUMMARY Embodiments of this disclosure, as defined in the appended claims, provide methods for handling cell connection failure, a terminal device, and a network-side device, to accurately detect a cell connection failure, and properly handle the cell connection failure. The present invention is defined in the accompanying claims. In the embodiments of this disclosure, whether connecting to a target serving cell has failed is monitored, and in a case of determining that connecting to the target serving cell has failed, corresponding connection failure handling is performed based on serving cell related information. Specifically, the connection failure handling may be performed based on at least one of the number of serving cells and a cell type. As such, a cell connection failure is accurately detected, and a proper connection failure handling manner is determined for the cell connection failure based on specific related information of the serving cell, so as to handle the failure timely and efficiently according to the connection failure handling manner, thereby autonomously recovering the cell connection and improving reliability of data transmission. BRIEF DESCRIPTION OF DRAWINGS The drawings described herein are intended for a further understanding of this disclosure and constitute a part of this disclosure. Example embodiments of this disclosure and descriptions thereof are intended to explain this disclosure, and do not constitute any inappropriate limitation on this disclosure. In the accompanying drawings: FIG. 1 is a schematic flowchart of a method for handling cell connection failure according to an embodiment of this disclosure;FIG. 2 is a schematic diagram of a time window according to an embodiment of this disclosure;FIG. 3 is a schematic diagram of another time window according to an embodiment of this disclosure;FIG. 4 is a schematic flowchart of a second method for handling cell connection failure according to an embodiment of this disclosure which is not part of the present claimed invention;FIG. 5 is a schematic structural diagram of a terminal device according to an embodiment of this disclosure;FIG. 6 is a schematic structural diagram of a network-side device according to an embodiment of this disclosure which is not part of the present claimed invention;FIG. 7 is a schematic structural diagram of a second terminal device according to an embodiment of this disclosure; andFIG. 8 is a schematic structural diagram of a second network-side device according to an embodiment of this disclosure which is not part of the present claimed invention. DETAILED DESCRIPTION The following clearly and completely describes the technical solutions in the embodiments of this disclosure with reference to the accompanying drawings in the embodiments of this disclosure. Apparently, the described embodiments are some rather than all of the embodiments of this disclosure. In related art, for new radio (New Radio, NR) mobile communications systems (NR system for short), currently a