Method and apparatus for reporting CHO time information

Abstract

Embodiments of the present application relate to a method and apparatus for reporting time information of a conditional handover (CHO). In an embodiment of the present application, the method comprises: receiving configuration information about CHO, and transmitting time information of CHO in response to at least one failure occurring during the CHO process.

Description

Technical Field

[0001] Embodiments of the present application generally relate to wireless communication technology, and more particularly, to a method and apparatus for reporting time information of a conditional handover (CHO). Background Art

[0002] The ability to perform handovers between cells is a requirement for any cellular network. Mobility removes location-based anchors, improves user experience and reduces hardware installation constraints. However, providing high-quality mobility services has traditionally relied on the calibration and configuration of mobility parameters by network operators. In order to reduce network configuration work and allow the network to adapt to changing environments, the concept of self-optimizing network (SON) was introduced in the 3GPP protocol.

[0003] In the context of SON, Mobility Robustness Optimization (MRO) refers to a class of processes that allow a cellular network to select its own set of optimal mobility parameters. Such processes will run autonomously across the network in a centralized or decentralized manner without human intervention.

[0004] 5G MRO is introduced in Release 16 (R16) as one of the SON features. One of the functions of MRO is to detect connection failures due to early or late handover or handover to the wrong cell. These problems are defined in R16 as follows:

[0005] - [Intra-system late handover] Radio link failure (RLF) occurs after a user equipment (UE) stays in a cell for a long time; the UE attempts to re-establish the radio link connection in a different cell.

[0006] - [Intra-system premature handover] RLF occurs shortly after a successful handover from a source cell to a target cell, or a handover failure occurs during the handover procedure; the UE attempts to re-establish the radio link connection in the source cell.

[0007] - [Intra-system handover to wrong cell] RLF occurs shortly after a successful handover from a source cell to a target cell, or a handover failure occurs during the handover procedure; the UE attempts to re-establish the radio link connection in a cell other than the source cell and the target cell.

[0008] In MRO for traditional handover, UE reported time (or UE reported time information) is used. "UE reported time" indicates the time elapsed since the last handover was initialized until the connection failed. In the RLF report, two types of UE reported time are reported from the UE to the network:

[0009] UE reported time / TimeConnFailure:

[0010] - This IE is used to indicate the time elapsed since the last HO initialization until the connection failed.

[0011] - In case of handover failure, T304 expires (reconfiguration with synchronization failure), the UE shall set timeConnFailure to the time elapsed since the last RRCReconfiguration message containing reconfigurationWithSync was received.

[0012] - In case of detected radio link failure, the UE shall set timeConnFailure to the time elapsed since the receipt of the last RRCReconfiguration message containing reconfigurationWithSync.

[0013] TimeSinceFailure:

[0014] - This field is used to indicate the time that has elapsed since the connection (establishment) failed.

[0015] - When the UE starts reporting an RLF report, the UE shall set timeSinceFailure to the time elapsed since the last radio link or handover failure in the NR.

[0016] The time reported by the UE is used for the MRO detection mechanism as follows:

[0017] -[Too late handover within the system]: There was no recent handover for the UE before the connection failure, for example, the time reported by the UE does not exist or is greater than the configured threshold (e.g., Tstore_UE_cntxt)

[0018] -[Premature intra-system handover]: There was a recent handover for the UE before the connection failure, for example, the time reported by the UE is less than a configured threshold (e.g., Tstore_UE_cntxt), and the first re-establishment attempt cell / the cell that the UE attempts to reconnect to is the cell that served the UE when the last handover was initialized.

[0019] - [Intra-system handover to wrong cell]: There was a recent handover for the UE before the connection failure, for example, the time reported by the UE is less than a configured threshold (for example, Tstore_UE_cntxt), and the first re-establishment attempt cell / the cell that the UE attempts to reconnect to is neither the cell that served the UE when the last handover was initialized, nor the cell that served the UE when the RLF occurred or the cell to which the handover was initialized. Summary of the invention

[0020] Embodiments of the present application provide a method and device for reporting time information of CHO.

[0021] An embodiment of the present application provides a method. The method may include: receiving configuration information about a conditional handover (CHO), and transmitting time information of the CHO in response to at least one failure occurring during the CHO process.

[0022] In an embodiment of the present application, the time information of the CHO may include at least one of the following: a first failure time from an event to the failure of the at least one failed CHO, and a second failure time from the failure of the at least one failed CHO.

[0023] In an embodiment of the present application, the first failure time may include at least one of the following: first time information indicating the time elapsed from the execution initialization of the first CHO configuration until the first CHO fails; second time information indicating the time elapsed from the evaluation initialization of the first CHO configuration until the first CHO fails; third time information indicating the time elapsed from the evaluation of the first CHO configuration; fourth time information indicating the time elapsed from the execution initialization of the first CHO configuration until the second CHO fails; fifth time information indicating the time elapsed from the execution initialization of the second CHO configuration until the second CHO fails; sixth time information indicating the time elapsed from the execution initialization of the first CHO configuration until the second CHO fails O configuration evaluation is initialized until the time when the second CHO fails; the seventh time information indicates the time from the time when the first CHO configuration is initialized until the radio link fails after the second CHO succeeds; the eighth time information indicates the time from the time when the second CHO configuration is initialized until the radio link fails after the second CHO succeeds; the ninth time information indicates the time from the time when the first CHO configuration evaluation is initialized until the radio link fails after the second CHO succeeds; and the tenth time information indicates the time from the last switch during the first CHO configuration evaluation until the radio link fails.

[0024] In an embodiment of the present application, the second failure time may include at least one of the following: eleventh time information, which indicates the time elapsed since the first CHO failed; twelfth time information, which indicates the time elapsed since the radio link failed after the second CHO succeeded; and thirteenth time information, which indicates the time elapsed since the second CHO failed.

[0025] In an embodiment of the present application, the method may further include transmitting cell information associated with CHO. For example, the cell information associated with CHO may include at least one of the following: a triggered cell ID, a selected cell ID, and a list of cell IDs that satisfy part or all of the multiple switching execution conditions of CHO. The cell information associated with CHO may further include cell measurement results. In another example, the cell information associated with CHO may further include at least one of the following: a list of cell IDs that satisfy part of the multiple switching execution conditions of CHO, and time information of part of the multiple switching execution conditions of CHO.

[0026] Another embodiment of the present application provides a method. The method may include: receiving time information of CHO in response to at least one failure occurring during the CHO process.

[0027] In an embodiment of the present application, the time information of the CHO may further include a plurality of time information of the CHO, and a corresponding failed cell ID of each time information of the CHO.

[0028] In an embodiment of the present application, the method may further include forwarding the time information of the CHO to a neighbor node associated with the failed cell ID.

[0029] In an embodiment of the present application, the method may further include detecting a failure type according to time information of the CHO.

[0030] Another embodiment of the present application provides an apparatus. The apparatus may include at least one non-transitory computer-readable medium having computer-executable instructions stored therein; at least one receiver; at least one transmitter; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiver, and the at least one transmitter. The computer-executable instructions are programmed to implement the above method using the at least one receiver, the at least one transmitter, and the at least one processor.

[0031] According to an embodiment of the present application, the UE may send time information of the CHO reported by the UE to the network so that the network may detect the failure type of the conditional switching of the MRO (eg, switching too early, switching too late, or switching to the wrong cell). BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To describe the manner in which the advantages and features of the present application can be obtained, the description of the present application is presented by reference to specific embodiments of the application illustrated in the accompanying drawings. These drawings depict only example embodiments of the present application and therefore should not be considered limiting of its scope.

[0033] Figure 1The CHO process at the UE side according to some embodiments of the present application is described;

[0034] Figure 2 Another CHO process at the UE side according to some embodiments of the present application is described;

[0035] Figure 3 A flowchart illustrating a method for reporting the time of CHO according to some embodiments of the present application;

[0036] Figure 4 The CHO process at the UE side according to an embodiment of the present application is described;

[0037] Figure 5 Another CHO process at the UE side according to an embodiment of the present application is described;

[0038] Figure 6 The present invention is described in accordance with an embodiment of the present application. Figure 5 and a diagram of an exemplary scenario reporting the temporal information of CHO;

[0039] Figure 7 Another CHO process at the UE side according to an embodiment of the present application is described;

[0040] Figure 8 The present invention is described in accordance with an embodiment of the present application. Figure 7 and a diagram of an exemplary scenario reporting the temporal information of CHO;

[0041] Fig. 9 Another CHO process at the UE side according to an embodiment of the present application is described;

[0042] Fig.10 The present invention is described in accordance with an embodiment of the present application. Fig. 9 and a diagram of an exemplary scenario reporting the temporal information of CHO;

[0043] Fig.11 Another CHO process at the UE side according to an embodiment of the present application is described;

[0044] Fig.12 The present invention is described in accordance with an embodiment of the present application. Fig.11 and a diagram of an exemplary scenario reporting the temporal information of CHO;

[0045] Fig.13 Describe the apparatus according to some embodiments of the present application; and

[0046] Fig.14 Another device according to some other embodiments of the present application is described. DETAILED DESCRIPTION

[0047] The detailed description of the accompanying drawings is intended as a description of the preferred embodiments of the present application, and is not intended to represent the only form in which the present application can be practiced. It should be understood that the same or equivalent functions can be implemented by different embodiments intended to be included in the spirit and scope of the present application.

[0048] Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings.

[0049] Unlike conventional handover, the CHO procedure is defined as a handover procedure performed by the UE when one or more handover execution conditions are met. During the CHO procedure, the UE may start evaluating the execution conditions after receiving the CHO configuration information, and stop evaluating the execution conditions once the execution conditions are met.

[0050] The following principles may apply to CHO:

[0051] -CHO configuration contains the configuration of the CHO candidate cells generated by the candidate gNB and the execution conditions generated by the source gNB.

[0052] - The execution condition can consist of one or two trigger conditions (CHO events A3 / A5). Only a single reference signal (RS) type is supported, and up to two different trigger quantities (e.g., reference signal received power (RSRP) and reference signal received quality (RSRQ), RSRP and interference plus noise ratio (SINR)) can be configured at the same time to evaluate the CHO execution condition of a single candidate cell.

[0053] - Before any CHO execution conditions are met, upon receiving a Handover (HO) command (without CHO configuration), the UE performs the HO procedure regardless of any previously received CHO configuration.

[0054] - When performing CHO, ie starting from the time when the UE starts synchronizing with the target cell, the UE does not monitor the source cell.

[0055] Figure 1 The CHO procedure at the UE side is illustrated, where the CHO is successful.

[0056] like Figure 1 As shown in FIG. 1 , first, the UE receives configuration information about CHO (also referred to as CHO configuration) from a base station (BS). The CHO configuration contains the configuration of CHO candidate cells and execution conditions. The execution conditions may include one or two trigger conditions (e.g., including an A3 event or an A5 event, or including both A3 and A5 events as specified in 3GPP standard document TS38.331). Second, the UE performs conditional configuration evaluation, that is, the UE evaluates the execution conditions. Third, when the UE determines that one or more trigger conditions are met, the UE performs CHO execution. Finally, in this embodiment, CHO is successful.

[0057] In the embodiments of the present application, the BS may also be referred to as an access point, an access terminal, a base station, a base station unit, a macro cell, a node B, an evolved node B (eNB), a gNB, a home node B, a relay node or a device, or described using other terms used in the art. A BS is typically part of a radio access network, which may include one or more controllers communicatively coupled to one or more corresponding BSs. A UE may be a computing device, such as a desktop computer, a laptop computer, a personal digital assistant (PDA), a tablet computer, a smart TV (e.g., a TV connected to the Internet), a set-top box, a game console, a security system (including security cameras), a vehicle-mounted computer, a network device (e.g., a router, a switch, and a modem), etc. According to an embodiment of the present application, a UE may be a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a device with a subscriber identity module, a personal computer, a selective call receiver, or any other device capable of sending and receiving communication signals on a wireless network. In some embodiments of the present application, a UE may be a wearable device, such as a smart watch, a fitness band, an optical head-mounted display, etc. In addition, a UE may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal or a device, or described using other terminology used in the art.

[0058] Figure 2 Another CHO procedure at the UE side is described, where a CHO failure occurs and then CHO recovery succeeds.

[0059] 3GPP RAN2 has agreed on new recovery procedures for RLF, HO failure or CHO failure. Figure 2 As shown in FIG. 1 , when the initial CHO execution attempt fails or the HO fails (eg, Figure 2 ), the UE may perform cell selection. If the selected cell is a CHO candidate cell, and if the network configures the UE to attempt CHO after a HO failure or a CHO failure, the UE attempts CHO execution again (e.g. Figure 2 Otherwise, perform the rebuild process. Figure 2 In the embodiment shown in , CHO rapid recovery was successful.

[0060] As discussed in MRO, the time of UE reporting is very important for failure type detection (e.g., too early handover, too late handover, and handover to the wrong cell). However, the time of existing UE reporting is defined for traditional handover, and it is not suitable for CHO. In some embodiments of the present application, the time of UE reporting is redefined for the CHO case, so that the network can detect the failure type more accurately in the CHO case.

[0061] Figure 3 A flow chart illustrating a method for reporting time information of CHO according to some embodiments of the present application. Figure 3 The method in can be executed by UE.

[0062] like Figure 3 As shown in FIG. 3 , in step 301, the UE may receive configuration information about CHO from a BS (eg, a source BS). For example, the CHO configuration information may include configurations of CHO candidate cells generated by the candidate BS and execution conditions generated by the source BS.

[0063] The execution condition may include one or two trigger conditions. For example, when the execution condition includes one trigger condition, the trigger condition may be an A3 event or an A5 event as specified in the 3GPP standard document TS38.331. When the execution condition includes two trigger conditions, the two trigger conditions may be an A3 event and an A5 event as specified in the 3GPP standard document TS38.331. In addition, only a single reference signal (RS) type may be used to evaluate the execution condition of a single cell, and up to two different execution quantities may be configured at the same time to evaluate the execution condition of a single cell. For example, the two different execution quantities may be RSRP and RSRQ, or RSRP and SINR, etc.

[0064] In step 302, the UE may transmit the time information of CHO in response to at least one failure occurring during the CHO process. In some embodiments of the present application, the time information of CHO may include two kinds of failure time information, the first being the failure time from the event to the CHO failure (which may be referred to as "UE reported time" similar to the current protocol), and the second being the failure time since the CHO failure (which may be referred to as the time since the failure).

[0065] The method for reporting the time of CHO will be described in detail below in conjunction with the embodiments of the present application.

[0066] Figure 4 The CHO process at the UE side according to an embodiment of the present application is described.

[0067] In this embodiment, CHO is configured for the UE, an initial CHO is performed at the UE but fails, and the network (eg, BS) does not configure the UE to attempt CHO again after the initial HO fails or the CHO fails.

[0068] like Figure 4As shown in , first, the UE receives CHO configuration information (or CHO configuration). The CHO configuration may include the configuration of the CHO candidate target cells generated by the candidate BS and the execution conditions generated by the source BS. For example, the network configures the UE with one or more candidate target cells in the CHO configuration. The network may provide the configuration parameters of the candidate target cells, for example, in the ConditionalReconfiguration IE. Therefore, the UE may use the configuration parameters to perform a handover to one of the target cells.

[0069] Second, the UE performs conditional configuration evaluation. For example, after receiving the CHO configuration from the network, the UE performs conditional configuration evaluation. The execution condition may include one or two trigger conditions (e.g., only A3 event, only A5 event, or both A3 and A5 events). If the UE determines that all trigger conditions are met, the UE regards the target candidate cell as a triggered cell and initiates CHO configuration execution.

[0070] Third, the UE performs CHO configuration execution (i.e., Figure 4 For example, if there are more than one triggered cells, the UE will select one of the existing triggered cells as the selected cell for CHO configuration execution. The UE will apply the configuration parameters of the selected cell and access the target cell. However, in this embodiment, CHO fails, i.e., CHO failure occurs (e.g., T304 expires).

[0071] In this embodiment, the network does not configure the UE to attempt CHO after a CHO failure (e.g., attemptCondReconfig is not configured). In response to the CHO failure, the UE may perform a reestablishment. For example, the UE may perform a normal radio resource control (RRC) connection reestablishment procedure (e.g., Figure 4 “RRC Reestablishment” shown in ).

[0072] After the RRC connection is reestablished, the UE may send an RLF report to the network, for example, via the RLF-Report IE. The RLF-Report IE may include one or more of the following UE-reported times (failure time from the event to the CHO failure) so that the network can more accurately detect the failure type in the case of CHO:

[0073] -Time 1 reported by UE (also called first time information, Figure 4 "T1" in ): indicates the time elapsed from the initialization of the first CHO configuration execution until the CHO fails (i.e., the first CHO failure). The first CHO configuration execution initialization is performed when the cell is selected for CHO configuration execution or all trigger conditions of the cell are met or the timer such as the first T304 starts. The first CHO failure may correspond to the expiration of the first T304;

[0074] -Time 2 reported by UE (also called second time information, Figure 4 "T2" in ): indicates the time elapsed from the initialization of the first conditional configuration evaluation until the first CHO fails. The first conditional configuration evaluation initialization is performed when the CHO configuration is received;

[0075] -Time 3 reported by UE (also called third time information, Figure 4 "T3" in ): indicates the time elapsed for the first conditional configuration evaluation. The first conditional configuration evaluation is performed from the time when the CHO configuration is received to the time when the cell is selected for CHO configuration execution or all trigger conditions of the cell are met or the first T304 is started.

[0076] An exemplary application scenario may be described as herein. For example, the UE has continuous coverage from gNB1 (e.g., cell A), but the UE determines to perform CHO to gNB2 (e.g., cell B). That is, the serving cell of the UE before the CHO is cell A of gNB1, and the target cell selected by the UE is cell B of gNB2. However, when the UE exits the coverage area of ​​cell B, a CHO failure occurs, and the UE must reconnect to gNB1 (cell A).

[0077] The UE may send a RLF report including the above one or more UE reported times (i.e., T1, T2, and T3) and selected or failed cell information (including cell ID, such as New Radio (NR) Cell Group ID (NCGI) of the selected or failed cell) to gNB1. Based on the selected cell information, gNB1 forwards the RLF report including the above UE reported times to gNB2. In an example, if the UE reported time is less than the corresponding configured threshold (e.g., Tstore_UE_cntxt), then gNB2 determines that CHO occurs prematurely. gNB2 may send a Handover Report message with a Premature CHO indication to gNB1.

[0078] Figure 5 Another CHO process at the UE side according to an embodiment of the present application is described.

[0079] In this embodiment, CHO is configured for the UE. At the same time, the UE is configured to try CHO again after the initial CHO execution fails, for example, attemptCondReconfig is configured.

[0080] like Figure 5 As shown in the figure, it is used to receive CHO configuration, conditional configuration evaluation, and CHO execution operations and Figure 4 The operations are the same as in , and for the sake of brevity, they will not be described in detail.

[0081] exist Figure 5 In the example, during the initial CHO execution, CHO fails, i.e., CHO failure occurs (e.g., T304 expires). Because the UE is configured to retry CHO after the initial HO failure or CHO failure. That is, attemptCondReconfig is configured, and the UE will retry CHO execution (this is also called the second CHO, such as Figure 5 “CHO recovery” shown in ).

[0082] In this embodiment, the second CHO is successful. After this, the UE may send an RLF report to the network (e.g., via the RLF-Report IE). The RLF-Report IE may include one or more of the following UE-reported times (failure time from the event to the CHO failure) so that the network can more accurately detect the failure type in the case of CHO:

[0083] -Time 1 reported by UE (also called first time information, Figure 5 "T1" in ): indicates the time elapsed from the initialization of the first CHO configuration execution until the CHO fails (first CHO failure). The first CHO configuration execution initialization is performed when the cell is selected for CHO configuration execution or all trigger conditions of the cell are met or the first T304 starts. The first CHO failure may correspond to the expiration of the first T304.

[0084] -Time 2 reported by UE (also called second time information, Figure 5 "T2" in ): indicates the time elapsed from the initialization of the first conditional configuration evaluation until the first CHO fails. The first conditional configuration evaluation initialization is performed when the CHO configuration is received.

[0085] -Time 3 reported by UE (also called third time information, Figure 5 "T3" in ): indicates the time elapsed for the first conditional configuration evaluation. From receiving the CHO configuration to the cell being selected for CHO configuration execution or all triggering conditions of the cell being met or starting from the second T304, the first conditional configuration evaluation is performed.

[0086] The UE may also report the time since the failure to the network in the RLF-report:

[0087] -Time 1 since the failure (also called the eleventh time information, Figure 5 "T11" in ): indicates the time elapsed since the first CHO failure.

[0088] An exemplary scenario may be described as herein. For example, the serving cell for the UE before CHO is cell A of gNB1, the target cell first selected by the UE is cell B of gNB2, and the cell for the second CHO execution is cell C of gNB3. When the UE exits the coverage area of ​​cell B of gNB2, CHO failure occurs and the UE connects to gNB3 (cell C).

[0089] Figure 6 Description of the embodiments according to the present application Figure 5 and a diagram for reporting time information of CHO for the above exemplary scenario.

[0090] In step 601, the UE may send an RLF report to gNB3, wherein the RLF report includes the time of the above one or more UE reports (T1, T2, T3) and the time since the failure regarding the CHO failure (T11) and the failed cell information (including cell ID, such as NCGI).

[0091] In step 602, based on the failed cell information, gNB3 forwards the RLF report including the time of the above UE report and the time since the failure regarding the CHO failure to gNB2.

[0092] In step 603, after receiving the UE reported time from gNB3, gNB2 may determine the failure type based on the received UE reported time. In an example, if the UE reported time is less than the corresponding configured threshold (e.g., Tstore_UE_cntxt), then gNB2 determines that the CHO occurred too early. In another example, if the UE reported time is greater than the corresponding configured threshold (e.g., Tstore_UE_cntxt), then gNB2 determines that the CHO from cell A of gNB1 to cell B of gNB2 occurred too late.

[0093] In step 604, gNB2 may send a handover report message with the determined failure type (e.g., failure type indication) to gNB1.

[0094] Figure 7 Another CHO process at the UE side according to an embodiment of the present application is described.

[0095] In this embodiment, CHO is configured for the UE. At the same time, the UE is configured to try CHO again after the initial CHO fails, for example, attemptCondReconfig is configured. Although the second CHO is successful, RLF occurs after the second CHO.

[0096] like Figure 7 As shown in the figure, it is used to receive CHO configuration, conditional configuration evaluation, and CHO execution operations and Figure 4The operations are the same as in , and for the sake of brevity, they will not be described in detail.

[0097] exist Figure 7 In the embodiment, during the initial CHO execution, the initial CHO fails, that is, an initial (or first) failure occurs (e.g., T304 expires). In this embodiment, due to the configuration attemptCondReconfig, the UE will attempt the CHO execution again (this is also called the second CHO, such as Figure 7 “CHO recovery” shown in ).

[0098] However, after a successful second CHO, RLF may occur.

[0099] After detecting RLF, the UE may perform the normal RRC connection reestablishment procedure (e.g. Figure 7 “RRC Establishment” shown in ).

[0100] After the normal RRC connection reestablishment process, the UE may send an RLF report (e.g., RLF-Report IE) to the network. In addition to the above T1, T2, and T3, the RLF-Report IE may further include one or more of the following UE-reported times (failure time from the event to CHO failure), so that the network can more accurately detect the failure type in the case of CHO:

[0101] -Time 7 reported by UE (also called the seventh time information, Figure 7 "T7" in ): indicates the time elapsed from the initialization of the first CHO configuration execution until the radio link failure after the second CHO success. The first CHO configuration execution initialization is performed when a cell is selected for CHO configuration execution or all trigger conditions of the cell are met or the first T304 starts.

[0102] -Time 8 reported by the UE (also called the eighth time information, Figure 7 "T8" in ): indicates the time elapsed from the second CHO configuration execution initialization until the radio link failure after the second CHO success. The second CHO configuration execution initialization is performed when the cell is selected for CHO configuration execution / or fast recovery, or when all trigger conditions of the cell are met in the second CHO phase or the second T304 starts. That is, during the cell selection process after the first CHO failure, when the selected cell is a CHO candidate cell, the second CHO configuration execution initialization is performed.

[0103] -Time 9 reported by the UE (also called the ninth time information, in Figure 7 denoted as “T9” in the figure): indicates the time elapsed from the initialization of the first conditional configuration evaluation until the radio link failure after the second CHO succeeds.

[0104] The UE may also report the time since the failure to the network in the RLF-report:

[0105] -Time 1 since the failure (also called the eleventh time information, Figure 5 "T11" in ): indicates the time elapsed since the first CHO failure.

[0106] - Time 2 since the failure (also called twelfth time information, Figure 7 "T12" in ): indicates the time elapsed since the radio link failure after the second CHO success.

[0107] An exemplary scenario may be described as herein. For example, the serving cell of the UE before the CHO is cell A of gNB1, the initial (first) target cell selected by the UE in the first CHO is cell B of gNB2, the cell of the second CHO is cell C of gNB3, and the UE reconnects to gNB4 (cell D).

[0108] Figure 8 Description of the embodiments according to the present application Figure 7 and a diagram for reporting time information of CHO for the above exemplary scenario.

[0109] In step 801, the UE may send two RLF reports to gNB4. For example, RLF-Report 1 may include one or more of the above UE reported times (e.g., T1, T2, T3) and the time since the failure regarding the first CHO failure (T11) and the first CHO failure cell information (first failed cell ID, such as NCGI). RLF-Report 2 may include one or more of the above UE reported times (T7, T8, T9) and the time since the failure regarding the second CHO failure (T12) and the RLF cell information (second failed cell ID, such as NCGI).

[0110] In step 802, based on the first CHO failure cell information, gNB4 forwards RLF-Report 1 including the time of one or more UE reports and the time since the failure of the first CHO failure to gNB2. Similarly, in step 803, based on the RLF cell information, gNB4 forwards RLF-Report 2 including the time of one or more UE reports and the time since the failure of the second CHO failure to gNB3.

[0111] In step 804, after receiving RLF-Report 1, gNB2 may determine the failure type based on the time reported by the UE regarding the first CHO failure. In an example, if the time reported by the UE is less than the corresponding configured threshold (e.g., Tstore_UE_cntxt), then gNB2 determines that the CHO occurred too early. In another example, if the time reported by the UE is greater than the corresponding configured threshold (e.g., Tstore_UE_cntxt), then gNB2 determines that the CHO occurred too late.

[0112] In step 805, gNB2 may send a handover report message with the determined failure type (e.g., failure type indication) to gNB1.

[0113] Similarly, in step 806, after receiving RLF-Report 2, gNB3 may determine the failure type according to the time of the second CHO failure reported by the received UE. In step 807, gNB3 may send a handover report message with the determined failure type (e.g., failure type indication) to gNB1.

[0114] exist Figure 8 In the above embodiment, two RLF reports (i.e., RLF-Report 1 and RLF-Report 2) are transmitted to gNB4, and gNB4 independently forwards RLF-Report 1 and RLF-Report 2 to gNB2 and gNB3. In another embodiment, the UE may transmit one RLF report including all time information in RLF-Report 1 and RLF-Report 2 to gNB4, and gNB4 forwards the RLF report including all information to gNB2 and gNB3. gNB2 may select time information related to itself (time information about the first CHO failure), and further determine the failure type based on the selected time information. gNB3 may perform similar operations.

[0115] Fig. 9 Another CHO process at the UE side according to an embodiment of the present application is described.

[0116] In this embodiment, CHO is configured for the UE. At the same time, the UE is configured to try CHO again after the initial CHO execution fails, for example, attemptCondReconfig is configured. However, the second CHO also fails.

[0117] like Fig. 9 As shown in the figure, the operations and Figure 4 The operations are the same as in , and for the sake of brevity, they will not be described in detail.

[0118] exist Fig. 9 In the embodiment, during the initial CHO execution, CHO fails, that is, CHO failure occurs (for example, the first T304 expires). In this embodiment, due to the configuration attemptCondReconfig, the UE will attempt CHO execution again (this is also called the second CHO, such as Fig. 9 ). However, the second CHO fails (eg, the second T304 expires).

[0119] In response to the second CHO failure, the UE may perform a normal RRC connection reestablishment procedure (eg Fig. 9 “RRC Reestablishment” shown in ).

[0120] After the normal RRC connection reestablishment process, the UE may send an RLF report to the network (e.g., via RLF-Report IE). In addition to the above T1, T2, and T3, the RLF-Report IE may further include one or more of the following UE-reported times (failure time from the event to CHO failure), so that the network can more accurately detect the failure type in the case of CHO:

[0121] -Time 4 reported by UE (also called fourth time information, Fig. 9 "T4" in ): indicates the time elapsed from the initialization of the first CHO configuration execution until the second CHO fails. When a cell is selected for CHO configuration execution or all trigger conditions of the cell are met or the first T304 starts, the first CHO configuration execution initialization is performed.

[0122] -Time 5 reported by the UE (also called the fifth time information, Fig. 9 "T5" in ): indicates the time elapsed from the second CHO configuration execution initialization until the second CHO fails. The second CHO configuration execution initialization is performed when the cell is selected for CHO configuration execution / or fast recovery, or when all trigger conditions of the cell are met in the second CHO phase or the second T304 starts. That is, during the cell selection process after the first CHO fails, when the selected cell is a CHO candidate cell, the second CHO configuration execution initialization is performed.

[0123] -Time 6 reported by the UE (also called the sixth time information, Fig. 9 "T6" in ): indicates the time elapsed from the initialization of the first CHO configuration evaluation until the second CHO fails (eg, the second T304 expires).

[0124] The UE may also report the time since the failure to the network in the RLF-report:

[0125] -Time 1 since the failure (also called the eleventh time information, Fig. 9 "T11" in ): indicates the time elapsed since the first CHO failure (eg, the first T304 expires).

[0126] -Time 3 since the failure (also called the thirteenth time information, Fig. 9 "T13" in ): indicates the time elapsed since the second CHO failure (eg, the second T304 expires).

[0127] An exemplary scenario may be described as herein. For example, the serving cell of the UE before CHO is cell A of gNB1, the target cell selected by the UE in the first CHO is cell B of gNB2, the cell of the second CHO is cell C of gNB3, and the UE reconnects to gNB 4 (cell D) due to the failure of the second CHO.

[0128] Fig.10 Description of the embodiments according to the present application Fig. 9 and a diagram for reporting time information of CHO for the above exemplary scenario.

[0129] In step 1001, the UE may send two RLF reports (i.e., RLF-Report 1 and RLF-Report 2) to gNB4. RLF-Report 1 includes one or more of the above UE reported times (T1, T2, T3) and the time since the failure regarding the first CHO failure (T11) and the first CHO failure cell information (including the first failed cell ID, such as NCGI). RLF-Report 2 includes one or more of the above UE reported times (T4, T5, T6) and the time since the failure regarding the second CHO failure (T13) and RLF cell information (including the second failed cell ID, such as NCGI).

[0130] In step 1002, based on the first CHO failure cell information, gNB4 forwards RLF-Report 1 including the time of one or more UE reports and the time since the failure of the first CHO failure to gNB2. Similarly, in step 1003, based on the RLF cell information, gNB4 forwards RLF-Report 2 including the time of one or more UE reports and the time since the failure of the second CHO failure to gNB3.

[0131] Fig.10 The operations of steps 1003 to 1007 in are similar to Figure 8 The operations of steps 803 to 807 in will not be described in detail for the sake of brevity.

[0132] exist Fig.10In the above embodiment, two RLF reports including RLF-Report 1 and RLF-Report 2 are transmitted to gNB4, and gNB4 independently forwards RLF-Report 1 and RLF-Report 2 to gNB2 and gNB3. In another embodiment, the UE may transmit one RLF report including all time information in RLF-Report 1 and RLF-Report 2 to gNB4, and gNB4 forwards the RLF report including all time information to gNB2 and gNB3. gNB2 may select time information related to itself (time information about the first CHO failure), and further determine the failure type based on the selected time information. A similar operation may be performed by gNB3.

[0133] Fig.11 Another CHO process at the UE side according to an embodiment of the present application is described.

[0134] In this embodiment, CHO is configured for the UE, a first RLF occurs during conditional configuration evaluation, and the network configures the UE to attempt CHO again after the first RLF occurs, for example, configuring attemptCondReconfig. Although the second CHO is successful, a second RLF occurs again after the second CHO.

[0135] like Fig.11 As shown in FIG. 1 , after the last HO, the UE receives the CHO configuration. The operation for receiving the CHO configuration is the same as Figure 4 The operations are the same as in and will not be described in detail for the sake of brevity.

[0136] The UE may perform conditional configuration evaluation based on the CHO configuration. During the conditional configuration evaluation, RLF occurs. Due to the configuration attemptCondReconfig, the UE will attempt CHO again (also called second CHO, such as Fig.11 “CHO recovery” shown in ).

[0137] After the second CHO succeeds, the UE performs radio link monitoring, and then RLF occurs.

[0138] After detecting RLF, the UE will perform the normal RRC connection establishment process (such as Fig.11 “RRC Establishment” shown in ).

[0139] After the RRC connection is established, the UE may send an RLF report (e.g., RLF-Report IE) to the network. The RLF-Report IE may include one or more of the following UE-reported times (failure time from the event to CHO failure) so that the network can more accurately detect the failure type in the case of CHO:

[0140] -Time 8 reported by the UE (also called the eighth time information, Fig.11 "T8" in ): indicates the time elapsed from the initialization of the second CHO configuration execution until the radio link failure after the second CHO success. The second CHO configuration execution initialization is performed when the cell is selected for CHO configuration execution / or fast recovery, or when all trigger conditions of the cell are met in the second CHO phase or the second T304 starts.

[0141] -Time 10 reported by UE (also called the tenth time information, Fig.11 "T10" in ): indicates the time elapsed from the last handover until the radio link fails during the first condition configuration evaluation.

[0142] An exemplary scenario may be described as herein. Prior to conditional configuration evaluation, the serving cell for the UE is cell A of gNB1, the cell for CHO recovery is cell B of gNB2, and the UE reconnects to cell C of gNB3.

[0143] Fig.12 The present invention is described in accordance with an embodiment of the present application. Fig.11 and a diagram of an exemplary scenario reporting the temporal information of CHO.

[0144] In step 1201, the UE may send two RLF reports (i.e., RLF-Report 1 and RLF-Report 2) to gNB3. RLF-Report 1 may include the time (TS10) of the UE report on the first RLF and the first RLF cell (cell A) information (including the first failed cell ID, such as NCGI). RLF-Report 2 may include the time (T8) of the UE report on the second CHO failure and the second RLF cell (cell B) information (including the second failed cell ID, such as NCGI).

[0145] In step 1202, based on the first RLF cell (cell A) information, gNB3 forwards RLF-Report 1 containing the time of the first RLF reported by the UE to gNB1. Similarly, in step 1203, based on the second RLF cell (cell B) information, gNB3 forwards RLF-Report 2 containing the time of the second CHO failure reported by the UE to gNB2.

[0146] In step 1204, after receiving RLF-Report 1, gNB1 may determine the failure type based on the time of the first RLF reported by the received UE.

[0147] Similarly, in step 1205, after receiving RLF Report 2, gNB2 may determine the failure type based on the time of the second CHO failure reported by the received UE. In step 1206, gNB2 may send a handover report message with the determined failure type (e.g., failure type indication) to gNB1.

[0148] exist Fig.12 In the above embodiment, two RLF reports including RLF-Report 1 and RLF-Report 2 are transmitted to gNB3, and gNB3 independently forwards RLF-Report 1 and RLF-Report 2 to gNB1 and gNB2. In another embodiment, the UE may transmit one RLF report including all time information in RLF-Report 1 and RLF-Report 2 to gNB3, and gNB3 forwards the RLF report including all time information to gNB1 and gNB2. gNB1 may select time information related to itself (time information about the first RLF), and further determine the failure type based on the selected time information. Similar operations may be performed by gNB2.

[0149] In an embodiment of the present application, the UE may transmit cell information associated with CHO to the network. For example, the cell information associated with CHO may include at least one of the following: a triggered cell ID; a selected cell ID; and a partial or complete list of cell IDs that meet multiple switching execution conditions of CHO.

[0150] In one example, during the conditional configuration evaluation phase, there may be many cells that can meet the conditions specified in TS 38.331:

[0151] 1> If there is more than one triggering cell:

[0152] 2> Select one of the triggered cells as the selected cell for CHO configuration execution;

[0153] In another example, for the above-mentioned embodiment of the present application, in the RLF-Report IE, the UE may report the selected cell / triggered cell ID to the network and also report a list of cell IDs that meet the conditions (optionally with measurement results), so that the network can detect and analyze failure problems. If only one of the conditions is met, the UE may also report partially met information (a list of cell IDs that partially meet the conditions, time information of the condition being met, and measurement results) to the network.

[0154] In the above-mentioned embodiments of the present application, after CHO is performed and failure occurs, the UE may send UE-reported CHO time information to the network so that the network can detect the failure type of conditional switching of MRO (for example, switching too early, switching too late, or switching to the wrong cell).

[0155] Fig.13 The device according to some embodiments of the present application is described. In some embodiments of the present disclosure, the device 1300 may be the UE in the above embodiments of the present application.

[0156] like Fig.13 As shown in , the device 1300 may include a receiver 1301, a transmitter 1303, a processor 1305, and a non-transitory computer-readable medium 1307. The non-transitory computer-readable medium 1307 has computer-executable instructions stored therein. The processor 1305 is configured to be coupled to the non-transitory computer-readable medium 1307, the receiver 1301, and the transmitter 1303. It is considered that, according to actual requirements, in some other embodiments of the present application, the device 1300 may include more computer-readable media, receivers, transmitters, and processors. In some embodiments of the present application, the receiver 1301 and the transmitter 1303 are integrated into a single device, such as a transceiver. In certain embodiments, the device 1300 may further include an input device, a memory, and / or other components.

[0157] In some embodiments of the present application, the non-transitory computer-readable medium 1307 may have computer-executable instructions stored thereon to enable a processor to implement a method according to an embodiment of the present application.

[0158] Fig.14 Another device according to some embodiments of the present application is described. In some embodiments of the present disclosure, the device 1400 may be the BS in the above embodiments of the present application.

[0159] like Fig.14 As shown in , the device 1400 may include a receiver 1401, a transmitter 1403, a processor 1405, and a non-transitory computer-readable medium 1407. The non-transitory computer-readable medium 1407 has computer-executable instructions stored therein. The processor 1405 is configured to be coupled to the non-transitory computer-readable medium 1407, the receiver 1401, and the transmitter 1403. It is considered that, according to actual requirements, in some other embodiments of the present application, the device 1400 may include more computer-readable media, receivers, transmitters, and processors. In some embodiments of the present application, the receiver 1401 and the transmitter 1403 are integrated into a single device, such as a transceiver. In certain embodiments, the device 1400 may further include an input device, a memory, and / or other components.

[0160] In some embodiments of the present application, the non-transitory computer-readable medium 1407 may have computer-executable instructions stored thereon to enable a processor to implement a method according to an embodiment of the present application.

[0161] Those skilled in the art should understand that with the development and advancement of technology, the terms described in this application may change and should not affect or limit the principles and spirit of this application.

[0162] Those of ordinary skill in the art will appreciate that the steps of the methods described in conjunction with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In addition, in some aspects, the steps of the method may reside as one or any combination or set of codes and / or instructions on a non-transitory computer-readable medium that may be incorporated into a computer program product.

[0163] Although the present disclosure has been described with its specific embodiments, it is apparent that many alternatives, modifications and variations may be apparent to those skilled in the art. For example, the various components of the embodiments may be interchanged, added or replaced in other embodiments. In addition, all elements of each figure are not necessarily required for the operation of the disclosed embodiments. For example, a person skilled in the art of the disclosed embodiments will be able to make and use the teachings of the present disclosure by simply adopting elements of independent technical solutions. Therefore, the embodiments of the present disclosure as described herein are intended to be illustrative, not restrictive. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0164] In this document, the term "comprises, comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements that are not explicitly listed or inherent to such process, method, article or equipment. In the absence of more constraints, an element beginning with "a, an" or the like does not exclude the presence of additional identical elements in the process, method, article or equipment including the element. In addition, the term "another" is defined as at least a second or more. The terms "include", "have" and the like as used herein are defined as "include".

Claims

1. A device for supporting reporting time information of conditional switching CHO, comprising: at least one non-transitory computer-readable medium having computer-executable instructions stored therein; at least one receiver; at least one transmitter; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiver, and the at least one transmitter; The computer executable instructions are programmed to implement a method comprising: Receive configuration information about CHO; and Transmitting CHO time information in response to at least one failure occurring during a CHO process, wherein the CHO time information includes a first failure time of the CHO failure from an event to the at least one failure, and wherein the first failure time also includes third time information indicating a time from receiving a first CHO configuration to a cell being selected for execution of the first CHO configuration.

2. The device according to claim 1, wherein the time information of the CHO further comprises: A second failure time since failure of the at least one failed CHO.

3. The apparatus of claim 1, wherein the first failure time comprises at least one of the further following: first time information indicating a time elapsed from when the first CHO configuration is initialized until when the first CHO fails; second time information indicating the time elapsed from the initialization of the first CHO configuration evaluation until the first CHO fails; fourth time information indicating the time elapsed from when the first CHO configuration is initialized until when the second CHO fails; fifth time information indicating the time elapsed from when the second CHO configuration is initialized until the second CHO fails; sixth time information, which indicates the time that has passed since the first CHO configuration evaluation was initialized until the second CHO failed; seventh time information indicating a time elapsed from when the first CHO configuration is initialized until a radio link failure after a second CHO succeeds; eighth time information indicating a time elapsed from when the second CHO configuration is initialized until the radio link fails after the second CHO succeeds; ninth time information indicating a time elapsed from the initialization of the first CHO configuration evaluation until a radio link failure after the second CHO succeeds; and Tenth time information indicating a time elapsed from a last handover until the radio link fails during the first CHO configuration evaluation.

4. The apparatus of claim 2, wherein the second failure time comprises at least one of: eleventh time information indicating the time elapsed since the first CHO failed; twelfth time information indicating the time elapsed since the radio link failure after the second CHO success; and Thirteenth time information indicating the time elapsed since the second CHO failed.

5. The device according to claim 3, wherein the time information of transmitting CHO comprises: In a case where a second CHO is not configured for the UE after the first CHO failure occurs, transmitting the first failure time including at least one of the following: the first time information; the second time information; and The third time information.

6. The device according to claim 3, wherein the time information of transmitting CHO comprises: In case a second CHO is configured and the second CHO succeeds after the first CHO failure occurs, transmitting a failure time of the CHO including at least one of: the first time information; the second time information; and The third time information.

7. The device according to claim 3, wherein the time information of transmitting CHO comprises: In case the radio link failure occurs during the first CHO configuration evaluation, transmitting a failure time of the CHO including at least one of: the eighth time information; and The tenth time information.

8. The apparatus according to claim 2, further comprising: Transmits cell information associated with CHO.

9. The apparatus according to claim 8, wherein the cell information associated with CHO comprises at least one of: The triggered cell ID; the selected cell ID; and A list of cell IDs that satisfy some or all of the multiple handover execution conditions of CHO.

10. A device for supporting reporting time information of a conditional handover CHO, comprising: at least one non-transitory computer-readable medium having computer-executable instructions stored therein; at least one receiver; at least one transmitter; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiver, and the at least one transmitter; The computer executable instructions are programmed to implement a method comprising: Send configuration information about CHO; and Receiving CHO time information in response to at least one failure occurring during a CHO process, wherein the CHO time information includes a first failure time of the CHO failure from an event to the at least one failure, and wherein the first failure time also includes third time information indicating a time from receiving a first CHO configuration to a cell being selected for execution of the first CHO configuration.

11. The device according to claim 10, wherein the time information of the CHO further comprises: A second failure time since failure of the at least one failed CHO.

12. The apparatus of claim 10, wherein the first failure time comprises at least one of: first time information indicating the time elapsed from when the first CHO performs configuration initialization until when the first CHO fails; second time information indicating the time elapsed from the initialization of the first CHO configuration evaluation until the first CHO fails; fourth time information indicating the time elapsed from when the first CHO configuration is initialized until when the second CHO fails; fifth time information indicating the time elapsed from when the second CHO configuration is initialized until the second CHO fails; sixth time information, which indicates the time that has passed since the first CHO configuration evaluation was initialized until the second CHO failed; seventh time information indicating a time elapsed from when the first CHO configuration is initialized until a radio link failure after a second CHO succeeds; eighth time information indicating a time elapsed from when the second CHO configuration is initialized until the radio link fails after the second CHO succeeds; ninth time information indicating a time elapsed from the initialization of the first CHO configuration evaluation until a radio link failure after the second CHO succeeds; and Tenth time information indicating a time elapsed from a last handover until the radio link fails during the first CHO configuration evaluation.

13. The apparatus of claim 11, wherein the second failure time comprises at least one of: eleventh time information indicating the time elapsed since the first CHO failed; twelfth time information indicating the time elapsed since the radio link failure after the second CHO success; and Thirteenth time information indicating the time elapsed since the second CHO failed.

14. The apparatus according to claim 12, wherein receiving the time information of the CHO comprises: In a case where a second CHO is not configured for the UE after the first CHO failure occurs, receiving the first failure time including at least one of the following: the first time information; the second time information; and The third time information.

15. The apparatus according to claim 12, wherein receiving the time information of the CHO comprises: In a case where a second CHO is configured and the second CHO succeeds after a failure of the first CHO occurs, receiving a failure time of the CHO including at least one of: the first time information; the second time information; and The third time information.

16. The apparatus of claim 12, wherein receiving time information of the CHO comprises: In case the radio link failure occurs during the first CHO configuration evaluation, receiving a failure time of the CHO including at least one of: the eighth time information; and The tenth time information.

17. The apparatus of claim 11, further comprising: Cell information associated with the CHO is received.

18. The apparatus according to claim 10, wherein the time information of the CHO further comprises: Multiple time information of CHO; and The corresponding failed cell ID for each time information of CHO.

19. The apparatus of claim 10, further comprising: The failure type is detected according to the time information of the CHO.

20. A method for supporting reporting of time information of a conditional switching CHO, comprising: Receive configuration information about CHO; and Transmitting CHO time information in response to at least one failure occurring during a CHO process, wherein the CHO time information includes a first failure time of the CHO failure from an event to the at least one failure, and wherein the first failure time also includes third time information indicating a time from receiving a first CHO configuration to a cell being selected for execution of the first CHO configuration.

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