Method and apparatus of MRO mechanism for mobility procedures

Abstract

Embodiments of the present application relate to methods and apparatus for mobility robustness optimization (MRO) mechanisms for mobility procedures, such as MRO mechanisms for conditional handover (CHO) procedures, or MRO mechanisms for conditional primary secondary cell group (PSCell) change / conditional PSCell addition (CPC / CPA) procedures, or MRO mechanisms for CHO including target master cell groups (MCG) and candidate secondary cell groups (SCG) for CPC / CPA procedures. According to embodiments of the present application, a network node includes a transceiver and a processor coupled to the transceiver, the processor configured to cause the network node to obtain cell information for recovery from a failure and to perform failure analysis when a failure occurs in one of the CHO procedures, a conditional PSCell addition or change (CPAC) procedure, and a CHO procedure including target MCG and candidate SCG for CPC / CPA procedures.

Description

Technical Field

[0001] Embodiments of the present application generally relate to a mobility robustness optimization (MRO) mechanism for mobility procedures, such as an MRO mechanism for conditional handover (CHO) procedures, or an MRO mechanism for conditional primary secondary cell group cell (PSCell) change / conditional PSCell addition (CPC / CPA) procedures, or an MRO mechanism for CHO including a target master cell group (MCG) and a candidate secondary cell group (SCG) for CPC / CPA procedures, methods and apparatuses thereof.

Background Art

[0002] In a multi-radio dual connectivity (MR-DC) scenario, a UE with multiple transceivers may be configured to use resources provided by two different nodes connected via a non-ideal backhaul. One node may provide new radio (NR) access, and the other may provide either universal mobile telecommunication system (UMTS) terrestrial radio access (UTRA) (E-UTRA) or NR access. One node may function as the master node (MN), and the other as the secondary node (SN). The MN and SN are connected via a network interface (for example, an Xn interface or X2 interface as specified in the 3rd Generation Partnership Project (3GPP) standards document), and at least the MN is connected to the core network.

[0003] Currently, Conditional PSCell Addition (CPA) and Conditional PSCell Modification (CPC) procedures are supported. A CPAC procedure may be either a CPA procedure or a CPC procedure. According to the agreement in the 3GPP standard document, a CPAC procedure is defined as a PSCell addition or PSCell modification performed by the UE when the configured CPAC execution conditions are met. The UE begins evaluating the CPAC execution conditions when it receives CPAC-related configuration information and stops evaluating the CPAC execution conditions when a PSCell addition and / or modification procedure is triggered or executed. Triggering or executing a PSCell addition and / or modification procedure means that when the CPAC execution conditions for a candidate PSCell are met (the "candidate PSCell" is sometimes referred to as the "CPAC candidate PSCell"), the UE determines the candidate PSCell to be the target PSCell and performs the PSCell addition or modification procedure on the target PSCell, for example, the UE performs an RA procedure on the target PSCell.

[0004] A CHO is defined as a handover performed by user equipment (UE) when one or more CHO execution conditions are met. When the UE receives CHO-related condition information (including, for example, one or more configurations and one or more CHO execution conditions associated with a candidate PCell), it begins evaluating one or more CHO execution conditions and stops evaluating the CHO execution conditions during a CHO execution or when one or more CHO execution conditions are met. A CHO execution means that when the CHO execution conditions for a candidate PCell are met (the "candidate PCell" is sometimes referred to as the "CHO ​​candidate PCell"), the UE determines the candidate PCell to be the target PCell and performs a PCell change procedure or PCell handover procedure with the target PCell, for example, the UE performs an RA procedure with the target PCell.

[0005] In a CHO that includes a target MCG and candidate SCG for a CPC / CPA procedure, when the UE receives a configuration for the CHO that includes the target MCG and candidate SCG for a CPC / CPA procedure (i.e., a CHO configuration that references or includes a CPC configuration or CPA configuration, or a configuration for a CHO using a candidate SCG procedure), for example, when the UE receives a configuration for a CHO candidate (target) PCell, CHO execution conditions, a configuration for a CPAC candidate (target) PSCell, and CPAC execution conditions, the CHO evaluation and the CPC evaluation or CPA evaluation may occur in parallel. For example, (when the UE receives a configuration for a CHO using a candidate SCG procedure) it simultaneously begins evaluating the CHO execution conditions for the candidate (target) PCell and the CPAC execution conditions for the candidate (target) PSCell. The UE does not execute a CPC or CPA unless the CHO execution conditions for the CHO candidate PCell are met.

[0006] Currently, details regarding MRO mechanisms for CHOs including target MCGs and candidate SCGs for CPC / CPA procedures (sometimes referred to as CHOs including target MCGs and candidate SCGs for CPA / CPC procedures, or CHOs using candidate SCG procedures, or CHOs including target MCGs and candidate SCG procedures, or CHOs including candidate target MCGs and candidate target SCG procedures for CPC / CPA procedures, or CHOs including candidate target MCGs and candidate target SCG procedures) have not yet been discussed. [Overview of the project] [Means for solving the problem]

[0007] Some embodiments of this application provide a network node. The network node includes a transceiver and a processor coupled to the transceiver, the processor configured to cause the network node to obtain cell information for recovery from a failure and to perform an analysis of the failure when a failure occurs in one of the CHOs, including a target master cell group (MCG) and a candidate secondary cell group (SCG) for a conditional handover (CHO) procedure, a conditional primary secondary cell group (PSCell) add or modify (CPAC) procedure, and a conditional PSCell modify / conditional PSCell add (CPC / CPA) procedure.

[0008] In some embodiments, the network node is a source master node (MN), and the processor is configured to cause the source MN to perform at least one of the following: modify the list of CPAC candidate PSCells; send first information to at least one candidate SN indicating that one or more CPAC candidate PSCells have been incorrectly selected; indicate one or more candidate MNs to send first information to at least one candidate SN; optimize the set of CPAC execution conditions; or send second information to one or more candidate MNs indicating that the set of CPAC execution conditions is improperly configured.

[0009] In some embodiments, the network node is a source master node (MN), the cell is a PSCell, and if the PSCell is not included in the list of CPAC candidate PSCells suggested by the source MN, the processor is configured to cause the source MN to revise the list of CPAC candidate PSCells.

[0010] In some embodiments, the network node is a source master node (MN), the cell is a PSCell, and if the PSCell is included in a first list of CPAC candidate PSCells suggested by the source MN but not in a second list of CPAC candidate PSCells selected by a candidate SN, the processor is configured to cause the source MN to send first information to the candidate SN indicating that the second list of CPAC candidate PSCells selected by the candidate SN is inappropriate, or to indicate one or more candidate MNs to send the first information to the candidate SN.

[0011] In some embodiments, the network node is a source master node (MN), the cell is a PSCell, and if the PSCell is included in a list of CPAC candidate PSCells selected by a candidate SN, the processor is configured to cause the source MN to optimize a set of CPAC execution conditions for the list of CPAC candidate PSCells, or to send second information to one or more candidate MNs indicating that the set of CPAC execution conditions is improperly configured.

[0012] In some embodiments, the network node is a source master node (MN), and the processor is configured to cause the source MN to perform at least one of the following: modify the list of CHO candidate PCells, send third information to at least one candidate MN indicating that one or more CHO candidate PCells have been incorrectly selected, or optimize the set of CHO execution conditions.

[0013] In some embodiments, the network node is a source master node (MN), the cell is a primary cell (PCell), and if the PCell is not included in the list of CHO candidate PCells suggested by the source MN, the processor is configured to cause the source MN to revise the list of CHO candidate PCells.

[0014] In some embodiments, the network node is a source master node (MN), the cell is a primary cell (PCell), and if the PCell is included in a first list of candidate CHO PCells suggested by the source MN but not in a second list of candidate CHO PCells selected by the candidate MN, the processor is configured to cause the source MN to send third information to the candidate MN indicating that the second list of candidate CHO PCells selected by the candidate MN is not suitable.

[0015] In some embodiments, the network node is a source master node (MN), the cell is a primary cell (PCell), and if the PCell is included in a list of CHO candidate PCells selected by the candidate MN, the processor is configured to cause the source MN to optimize a set of CHO execution conditions for the list of CHO candidate PCells.

[0016] In some embodiments, the processor is configured to cause the source MN to determine cell information, transmit cell information, or receive cell information.

[0017] In some embodiments, the processor is configured to cause the source MN to transmit or receive fault-related information relating to a fault.

[0018] In some embodiments, the network node is a candidate master node (MN), and the processor is configured to cause the candidate MN to perform at least one of the following: modify the list of CPAC candidate PSCells; send a fourth piece of information to at least one candidate SN indicating that one or more CPAC candidate PSCells have been incorrectly selected; optimize the set of CPAC execution conditions; or send a fifth piece of information to the source MN indicating that the set of CPAC execution conditions is improperly configured.

[0019] In some embodiments, the network node is a candidate master node (MN), the cell is a PSCell, and if the PSCell is not included in the list of CPAC candidate PSCells suggested by the candidate MN, the processor is configured to cause the candidate MN to modify the list of CPAC candidate PSCells.

[0020] In some embodiments, the network node is a candidate master node (MN), the cell is a PSCell, and if the PSCell is included in a first list of CPAC candidate PSCells suggested by the candidate MN but not in a second list of CPAC candidate PSCells selected by the candidate SN, the processor is configured to cause the candidate MN to send a fourth piece of information to the candidate SN indicating that the second list of CPAC candidate PSCells selected by the candidate SN is not appropriate.

[0021] In some embodiments, the network node is a candidate master node (MN), the cell is a PSCell, and if the PSCell is included in a list of CPAC candidate PSCells selected by the candidate MN, the processor is configured to cause the candidate MN to optimize a set of CPAC execution conditions for the list of CPAC candidate PSCells, or to send a fifth piece of information to the source MN indicating that the set of CPAC execution conditions is improperly configured.

[0022] In some embodiments, the network node is a candidate master node (MN), and the processor is configured to cause the candidate MN to perform at least one of the following: receive a sixth piece of information from the source MN indicating that at least one CHO candidate PCell has been incorrectly selected, or correct one or more CHO candidate PCells selected by the candidate MN.

[0023] In some embodiments, the processor is configured to cause the candidate MN to determine cell information, transmit cell information, or receive cell information.

[0024] In some embodiments, the processor is configured to cause the candidate MN to receive fault-related information related to a fault.

[0025] In some embodiments, the network node is a source secondary node (SN), and the processor is configured to cause the source SN to modify a list of CPAC candidate PSCs, transmit seventh information for indicating that one or more CPAC candidate PSCs are incorrectly selected to at least one candidate SN, indicate the source MN to cause the seventh information to be transmitted to at least one candidate SN, or perform at least one of optimizing a set of CPAC execution conditions.

[0026] In some embodiments, the network node is a source secondary node (SN), the cell is a PSCell, and if the PSCell is not included in the list of CPAC candidate PSCs suggested by the source SN, the processor is configured to cause the source SN to modify the list of CPAC candidate PSCs.

[0027] In some embodiments, the network node is a source secondary node (SN), the cell is a PSCell, and if the PSCell is included in the first list of CPAC candidate PSCs suggested by the source SN but not included in the second list of CPAC candidate PSCs selected by the candidate SN, the processor is configured to cause the source SN to transmit seventh information for indicating that the second list of CPAC candidate PSCs selected by the candidate SN is inappropriate to the candidate SN, or indicate the source MN to cause the seventh information to be transmitted to the candidate SN.

[0028] In some embodiments, the network node is a source secondary node (SN), the cell is a PSCell, and when the PSCell is included in the list of CPAC candidate PSCs selected by the candidate SN, the processor is configured to cause the source SN to optimize a set of CPAC execution conditions regarding the list of CPAC candidate PSCs.

[0029] In some embodiments, the processor is configured to cause the source SN to determine cell information, transmit cell information, or receive cell information.

[0030] In some embodiments, the processor is configured to cause the source SN to receive failure-related information related to a failure.

[0031] In some embodiments, the failure-related information includes at least one of a first type of satisfied execution condition, a second type of satisfied execution condition, information indicating whether the CPAC execution condition of the CPAC candidate PSCell is satisfied, information indicating whether the CHO execution condition of the CHO candidate PCell is satisfied, information indicating whether a candidate PSCell with a satisfied CPAC execution condition is associated with a candidate PCell with a satisfied CHO execution condition, for example, when the CPAC execution condition of the CPAC candidate PSCell is satisfied, information indicating whether the departure condition of the candidate PCell with a satisfied CHO execution condition is satisfied, for example, when the CHO execution condition of the CHO candidate PCell is satisfied, information indicating whether the departure condition of the candidate PSCell with a satisfied CPAC execution condition is satisfied, the time elapsed from when the CHO execution condition is satisfied until the CPAC execution condition is satisfied, or the time elapsed from when the CPAC execution condition is satisfied until the CHO execution condition is satisfied.

[0032] In some embodiments, the failure is one of an SCG failure, an MCG failure, a radio link failure (RLF), a CHO execution failure, and a CPAC execution failure.

[0033] In some embodiments, a failure occurs when configuration information regarding the CHO, including the target MCG and candidate SCG for the CPC / CPA procedure, is configured for the user equipment (UE), but neither the CHO execution nor the CPA / CPC execution has been initiated for the UE prior to the failure.

[0034] In some embodiments, the failure is defined as a delayed CHO, including the target MCG and candidate SCG for CPC / CPA.

[0035] In some embodiments, this example is that the CHO execution conditions for the CHO candidate primary cell (PCell) are met, but the CPA / CPC execution conditions for the non-CPAC candidate PSCell are met; the CHO execution conditions for the CHO candidate PCell are met first, and the CPA / CPC execution conditions for the CPAC candidate PSCell are met next, but the CPAC candidate PSCell is not associated with the CHO candidate PCell; when the CHO execution conditions for the CHO candidate PCell are met first, and the CPA / CPC execution conditions for the CPAC candidate PSCell are met next, the departure conditions for the CHO candidate PCell are met, and the CPAC candidate The following conditions must be met: the CPAC execution conditions for PSCell are met, but the CHO execution conditions for non-CHO candidate PCell are met; the CPAC execution conditions for CPAC candidate PSCell are met first, followed by the CHO execution conditions for CHO candidate PCell, but the CHO candidate PCell is not associated with CPAC candidate PSCell; the CPAC execution conditions for CPAC candidate PSCell are met first, followed by the CHO execution conditions for CHO candidate PCell, and the eviction conditions for CPAC candidate PSCell are met; and one of the following conditions must be met: the non-CHO execution conditions are met, and the non-CPAC execution conditions are met.

[0036] In some embodiments, a failure occurs in one of the following cases: a CPAC execution fails or an SCG failure occurs immediately after the successful completion of a CPAC execution; a CHO execution fails or an MCG failure occurs immediately after the successful completion of a CHO execution; or a CHO execution fails or an MCG failure occurs immediately after the successful completion of a CHO execution, and a CPAC execution fails or an SCG failure occurs immediately after the successful completion of a CPAC execution.

[0037] Some embodiments of the present application provide a candidate secondary node (SN). The candidate SN includes a transceiver and a processor coupled to the transceiver, the processor configured to cause the candidate SN to receive information indicating that one or more conditional primary secondary cell group cell (PSCell) add or modify (CPAC) candidate PSCells have been incorrectly selected, by receiving the information from a source master node (MN), a candidate MN, or a source SN, or by correcting one or more CPAC candidate PSCells.

[0038] In some embodiments, information is received when a failure occurs in one of the CHOs, including the target master cell group (MCG) and candidate SCG for the CPAC procedure and the conditional PSCell modification / conditional PSCell addition (CPC / CPA) procedure.

[0039] In some embodiments, the failure is one of the following: a secondary cell group (SCG) failure, a radio link failure (RLF), and a CPAC execution failure.

[0040] In some embodiments, a failure occurs when configuration information regarding the CHO, including the target MCG and candidate SCG for the CPC / CPA procedure, is configured for the user equipment (UE), but neither the CHO execution nor the CPA / CPC execution has been initiated for the UE prior to the failure.

[0041] In some embodiments, the failure is defined as a delayed CHO, including the target MCG and candidate SCG for CPC / CPA.

[0042] In some embodiments, this example is that the CHO execution conditions for the CHO candidate primary cell (PCell) are met, but the CPA / CPC execution conditions for the non-CPAC candidate PSCell are met; the CHO execution conditions for the CHO candidate PCell are met first, and the CPA / CPC execution conditions for the CPAC candidate PSCell are met next, but the CPAC candidate PSCell is not associated with the CHO candidate PCell; when the CHO execution conditions for the CHO candidate PCell are met first, and the CPA / CPC execution conditions for the CPAC candidate PSCell are met next, the departure conditions for the CHO candidate PCell are met, and the CPAC candidate The following conditions must be met: the CPAC execution conditions for PSCell are met, but the CHO execution conditions for non-CHO candidate PCell are met; the CPAC execution conditions for CPAC candidate PSCell are met first, followed by the CHO execution conditions for CHO candidate PCell, but the CHO candidate PCell is not associated with CPAC candidate PSCell; the CPAC execution conditions for CPAC candidate PSCell are met first, followed by the CHO execution conditions for CHO candidate PCell, and the eviction conditions for CPAC candidate PSCell are met; and one of the following conditions must be met: the non-CHO execution conditions are met, and the non-CPAC execution conditions are met.

[0043] In some embodiments, the failure occurs in one of the following cases: a failure in CPAC execution or an SCG failure immediately following the successful completion of CPAC execution; a failure in CHO execution or an MCG failure immediately following the successful completion of CHO execution; or a failure in CHO execution or an MCG failure immediately following the successful completion of CHO execution, and a failure in CPAC execution or an SCG failure immediately following the successful completion of CPAC execution.

[0044] Some embodiments of this application provide a user device (UE). The UE includes a transceiver and a processor coupled to the transceiver, the processor being configured to store fault-related information relating to a fault, wherein the fault occurs in a conditional handover (CHO) including a target master cell group (MCG) and a candidate secondary cell group (SCG) for a conditional primary secondary cell group (PSCell) change / conditional PSCell add (CPC / CPA) procedure, and to transmit the fault-related information.

[0045] In some embodiments, the failure-related information includes at least one of the following: the type of a first execution condition that has been met; the type of a second execution condition that has been met; information indicating whether the conditional PSCell Addition or Modification (CPAC) execution condition of a CPAC candidate PSCell has been met; information indicating whether the CHO execution condition of a CHO candidate PCell has been met; information indicating whether a candidate PSCell whose CPAC execution condition has been met is associated with a candidate primary cell (PCell) whose CHO execution condition has been met, for example, information indicating whether the departure condition of a candidate PCell whose CHO execution condition has been met has been met when the CPAC execution condition of a CPAC candidate PSCell has been met, for example, information indicating whether the departure condition of a candidate PSCell whose CPAC execution condition has been met has been met when the CHO execution condition of a CHO candidate PCell has been met; the time elapsed from when the CHO execution condition was met until the CPAC execution condition was met; or the time elapsed from when the CPAC execution condition was met until the CHO execution condition was met.

[0046] In some embodiments, the fault is one of the following: MCG fault, SCG fault, radio link fault (RLF), CHO execution fault, and conditional PSCell add or modify (CPAC) execution fault.

[0047] In some embodiments, the processor is configured to cause the UE to receive configuration information about the CHO, including a target MCG and candidate SCG for a CPC / CPA procedure, and a failure occurs when the configuration information has been received, but neither the CHO execution nor the CPA / CPC execution has been initiated for the UE prior to the failure.

[0048] In some embodiments, the failure is defined as a delayed CHO, including the target MCG and candidate SCG for CPC / CPA.

[0049] In some embodiments, examples include: the CHO execution conditions for the CHO candidate PCell are met, but the CPA / CPC execution conditions for the unconditional PSCell addition or modification (CPAC) candidate PSCell are met; the CHO execution conditions for the CHO candidate PCell are met first, and the CPA / CPC execution conditions for the CPAC candidate PSCell are met next, but the CPAC candidate PSCell is not associated with the CHO candidate PCell; the CHO execution conditions for the CHO candidate PCell are met first, and the CPA / CPC execution conditions for the CPAC candidate PSCell are met next, and the departure conditions for the CHO candidate PCell are met; CP The following conditions must be met: the CPAC execution conditions for the AC candidate PSCell are met, but the CHO execution conditions for the non-CHO candidate PCell are met; the CPAC execution conditions for the CPAC candidate PSCell are met first, followed by the CHO execution conditions for the CHO candidate PCell, but the CHO candidate PCell is not associated with the CPAC candidate PSCell; the CPAC execution conditions for the CPAC candidate PSCell are met first, followed by the CHO execution conditions for the CHO candidate PCell, and the eviction conditions for the CPAC candidate PSCell are met; and the non-CHO execution conditions are met, and the non-CPAC execution conditions are met.

[0050] In some embodiments, the failure occurs in one of the following cases: a failure in CPAC execution or an SCG failure immediately following the successful completion of CPAC execution; a failure in CHO execution or an MCG failure immediately following the successful completion of CHO execution; or a failure in CHO execution or an MCG failure immediately following the successful completion of CHO execution, and a failure in CPAC execution or an SCG failure immediately following the successful completion of CPAC execution.

[0051] Some embodiments of this application provide a method implemented by a network node. The method includes the steps of obtaining cell information for recovery from a failure and performing an analysis of the failure when a failure occurs in one of the CHOs, including a target master cell group (MCG) and a candidate secondary cell group (SCG) for a conditional handover (CHO) procedure, a conditional primary secondary cell group (PSCell) add or modify (CPAC) procedure, and a conditional PSCell modify / conditional PSCell add (CPC / CPA) procedure.

[0052] Some embodiments of this application provide a method implemented by a candidate secondary node (SN). This method includes receiving information indicating that one or more conditional primary secondary cell group cell (PSCell) add or modify (CPAC) candidate PSCells have been incorrectly selected, and performing at least one of the following: receiving information from a source master node (MN), a candidate MN, or a source SN, or correcting one or more CPAC candidate PSCells.

[0053] Some embodiments of this application provide a method to be implemented by a UE. The method includes the steps of storing fault-related information relating to a fault, wherein the fault occurs in a conditional handover (CHO) including a target master cell group (MCG) and a candidate secondary cell group (SCG) for a conditional primary secondary cell group (PSCell) change / conditional PSCell add (CPC / CPA) procedure, and transmitting the fault-related information.

[0054] Some embodiments of this application provide a device for wireless communication. The device includes a non-temporary computer-readable medium storing computer-executable instructions thereon, a receiving circuit, a transmitting circuit, and a processor coupled to the non-temporary computer-readable medium, the receiving circuit, and the transmitting circuit, wherein the computer-executable instructions cause the processor to perform the aforementioned method, which is carried out by a UE or network node (source MN, candidate MN, source SN, or candidate SN).

[0055] Details of one or more examples are described in the accompanying drawings and the description below. Other features, purposes, and advantages will become apparent from the description and drawings, as well as the claims.

[0056] To illustrate the manner in which the advantages and features of this application may be obtained, the description of this application is given by reference to specific embodiments thereof shown in the accompanying drawings. These drawings illustrate only exemplary embodiments of this application and should therefore not be considered to limit its scope. [Brief explanation of the drawing]

[0057] [Figure 1] This is a schematic diagram of a wireless communication system according to several embodiments of this application. [Figure 2] This figure shows an exemplary procedure for performing a fault analysis according to several embodiments of the present application. [Figure 3]This figure shows an exemplary procedure performed by candidate SN according to several embodiments of the present application. [Figure 4] This figure shows an exemplary procedure performed by a UE according to some embodiments of the present application. [Figure 5] This is a block diagram of an exemplary apparatus according to some embodiments of the present disclosure. [Modes for carrying out the invention]

[0058] The detailed description of the attached drawings is intended to describe preferred embodiments of this application and is not intended to represent only the forms in which this application may be practiced. It should be understood that the same or equivalent functionality may be achieved by different embodiments intended to be included within the spirit and scope of this application.

[0059] Next, we will refer in detail to several embodiments of this application, the examples of which are illustrated in the attached drawings. For the sake of understanding, the embodiments are provided under specific network architectures and new service scenarios, such as 3GPP 5G and 3GPP LTE Release 8. As network architectures and new service scenarios develop, all embodiments of this application are intended to be applicable to similar technical problems, and furthermore, the technical terms enumerated in this application may be changed, but this should not affect the principles of this application.

[0060] Figure 1 shows a schematic diagram of a wireless communication system according to several embodiments of this application.

[0061] As shown in Figure 1, the wireless communication system 100 may be a dual connectivity system 100 including at least one UE 101, at least one MN 102, and at least one SN 103. Specifically, the dual connectivity system 100 in Figure 1 includes, for illustrative purposes, one shown UE 101, one shown MN 102, and one shown SN 103. While a specific number of UE 101, MN 102, and SN 103 are shown in Figure 1, it is intended that any number of UE 101, MN 102, and SN 103 may be included in the wireless communication system 100.

[0062] Referring to Figure 1, UE101 may be connected to MN102 and SN103 via a network interface, for example, the Uu interface as specified in the 3GPP standard document. MN102 and SN103 may be connected to each other via a network interface, for example, the Xn interface as specified in the 3GPP standard document for NR-NR DC, NGEN-DC, or NE-DC, or the X2 interface as specified in the 3GPP standard document for EN-DC. MN102 may be connected to the core network via a network interface (not shown in Figure 1). UE101 may be configured to perform data transmission using the resources provided by MN102 and SN103.

[0063] MN102 may refer to a radio access node that provides control plane connectivity to the core network. In embodiments of this application, in an E-UTRA-NR Dual Connectivity (EN-DC) scenario, MN102 may be an eNB. In another embodiment of this application, in a next-generation E-UTRA-NR Dual Connectivity (NGEN-DC) scenario, MN102 may be an ng-eNB. In yet another embodiment of this application, in an NR-E-UTRA Dual Connectivity (NE-DC) scenario or an NR-NR Dual Connectivity (NR-DC) scenario, MN102 may be a gNB.

[0064] MN102 may be associated with a Master Cell Group (MCG). The MCG may refer to a group of serving cells associated with MN102, and may include a primary cell (PCell) and, optionally, one or more secondary cells (SCells) of the MCG. The PCell may provide control plane connectivity to UE101.

[0065] SN103 may refer to a radio access node that provides additional resources to UE101 but does not have a control plane connection to the core network. In embodiments of this application, in an EN-DC scenario, SN103 may be an en-gNB. In another embodiment of this application, in an NE-DC scenario, SN103 may be an ng-eNB. In yet another embodiment of this application, in an NR-DC or NGEN-DC scenario, SN103 may be a gNB.

[0066] SN103 may be associated with a secondary cell group (SCG). An SCG may refer to a group of serving cells associated with SN103, and may include a primary secondary cell (PSCell) and, optionally, one or more secondary cells (SCells). The PCell of an MCG and the PSCell of an SCG are sometimes called special cells (SpCell).

[0067] In some embodiments of this application, UE101 may include computing devices such as desktop computers, laptop computers, personal digital assistants (PDAs), tablet computers, smart televisions (e.g., internet-connected televisions), set-top boxes, game consoles, security systems (including security cameras), in-vehicle computers, and network devices (e.g., routers, switches, and modems). In some other embodiments of this application, UE101 may include portable wireless communication devices, smartphones, cellular phones, flip phones, devices having subscriber identification modules, personal computers, selective call receiving circuits, or any other device capable of sending and receiving communication signals over a wireless network.

[0068] In some other embodiments of this application, UE101 may include wearable devices such as smartwatches, fitness bands, and optical head-mounted displays. Furthermore, UE101 may be referred to as subscriber units, mobile, mobile stations, users, terminals, mobile terminals, wireless terminals, fixed terminals, subscriber stations, user terminals, or devices, or may be described using other technical terms used in the art.

[0069] Generally, a CHO is executed by the UE when at least one CHO execution condition is met. For example, a CHO execution is performed when one or two CHO execution conditions for a candidate PCell are met, and "CHO ​​execution" can be an action where the UE determines that the candidate PCell whose CHO execution conditions are met is the target PCell and performs a PCell change or handover with the target PCell, for example, the UE performs an RA procedure on the target PCell. The UE begins evaluating the CHO execution conditions when it receives the CHO configuration and stops evaluating the CHO execution conditions when at least one CHO execution condition is met. The CHO configuration includes a configuration about the CHO candidate PCell generated by the candidate BS (e.g., candidate (target) MN) and CHO execution conditions generated by the source BS (e.g., source MN).

[0070] CPAC is performed by the UE when one or more CPAC execution conditions are met. For example, CPAC execution is performed when at least one CPAC execution condition of a candidate PSCell is met, and "CPAC execution" can be an operation in which the UE determines the candidate PSCell whose CPAC execution condition is met as the target PSCell and performs PSCell addition or modification on the target PSCell, for example, the UE performs an RA procedure on the target PSCell. The UE begins evaluating the CPAC execution conditions when it receives the CPAC configuration and stops evaluating the CPAC execution conditions when at least one CPAC execution condition is met. The CPAC configuration (i.e., CPA configuration or CPC configuration) includes a configuration about the CPAC candidate PSCell generated by the candidate (target) SN, and CPAC execution conditions generated by the source SN or source MN.

[0071] One of the goals for enhancing mobility in 3GPP Release 18 is to explicitly define CHOs that include target MCGs and candidate SCGs for CPC / CPA procedures. CHOs that include target MCGs and candidate SCGs for CPC / CPA procedures may also be referred to as "CHOs that include candidate (target) MCGs and candidate (target) SCGs for CPC / CPA procedures," "CHOs that include target MCGs and candidate SCGs for CAP procedures, or CHOs that include target MCGs and candidate SCGs for CPC procedures," or "CHOs that use candidate SCG procedures." For example, the following scenario may be considered for CHOs that include target MCGs and candidate SCGs for CPC / CPA procedures. (1) Scenario 1 "CHO ​​using CPA": CHO from single connectivity to MR-DC connectivity, for example, CHO from source PCell1 to candidate (target) PCell2 using candidate (target) SN. In other words, in Scenario 1, single connectivity is changed to dual connectivity. (2) Scenario 2 "CHO ​​using CPC within SN": For example, a CHO from source PCell1 using SCG1 within SN1 to candidate (target) PCell2 using candidate (target) SCG within the same SN1. In other words, in Scenario 2, the PCell is changed and the PSCell is changed, but the SN is not changed. (3) Scenario 3 "CHO ​​using inter-SN CPC": A CHO from source PCell1 using SN1 (e.g., S-SN) (e.g., managed by S-MN) to candidate (target) PCell2 using a candidate (target) SN other than SN1 (e.g., T-SN) (e.g., managed by T-MN). In other words, in Scenario 3, the PCell is changed and the SN is changed.

[0072] A CHO configuration that refers to or includes a CPC configuration or a CPA configuration (intended to be applicable together) may be supported in a CHO that includes a target MCG and candidate SCG for a CPC / CPA procedure. In a CHO that includes a target MCG and candidate SCG for a CPC / CPA procedure, one or more CHO candidate PCells may be configured, one or two CHO execution conditions may be configured for one CHO candidate PCell, one or more associated CPAC candidate PSCells may be configured for one CHO candidate PCell, and one or two CPAC execution conditions may be configured for one CPAC candidate PSCell.

[0073] In a CHO that includes a target MCG and candidate SCG for a CPC / CPA procedure, the evaluation of the CHO execution conditions and the CPC / CPA execution conditions may be parallel or simultaneous. For example, the UE (when it receives a configuration for a CHO with a candidate SCG procedure) may simultaneously begin evaluating the execution conditions for the CHO candidate PCell and the CPAC candidate PSCell.

[0074] When the UE receives a configuration for a CHO that includes a target MCG and candidate SCG for a CPC / CPA procedure (i.e., a CHO configuration that points to or includes a CPC configuration or CPA configuration, or a configuration for a CHO using a candidate SCG procedure), for example, when the UE receives a configuration for a candidate (target) CHO PCell, CHO execution conditions, a configuration for a candidate (target) CPAC PSCell, and CPAC execution conditions, the CHO evaluation and the CPC or CPA evaluation may be in parallel. For example, the UE (when receiving a configuration for a CHO using a candidate SCG procedure) simultaneously begins evaluating the CHO execution conditions for the candidate (target) PCell and the CPAC execution conditions for the candidate (target) PSCell. The UE does not perform a CPC or CPA unless the CHO execution conditions for the candidate CHO PCell are met. The UE does not need to solve any of the nested conditional configuration containers to measure.

[0075] In a CHO that includes a target MCG and candidate SCG for a CPC / CPA procedure, the UE evaluates whether the CHO execution conditions and / or CPC / CPA execution conditions are met. If either the CHO execution conditions or the CPC / CPA execution conditions are not met, or if either the CHO execution or the CPC / CPA execution fails, an MCG failure and / or SCG failure will occur.

[0076] Currently, several challenges need to be addressed in the above scenario. To improve mobility robustness, for example, the MRO mechanism for the CHO, including the target MCG and candidate SCG for CPC / CPA procedures, should be considered, including what information from the UE is required for network nodes to perform MRO, and how network nodes perform root cause analysis for MRO, in order to modify the configuration of the CHO, including the target MCG and candidate SCG for CPC / CPA procedures.

[0077] Embodiments of this disclosure aim to address such challenges in the scenarios described above. For example, some embodiments define a “too-late CHO with a candidate SCG procedure” or a “too-late CHO with CPA / CPC execution.” In some embodiments, the UE needs to store and report failure-related information in order to enable MRO analysis regarding a CHO including a target MCG and candidate SCG for a CPC / CPA procedure. Some embodiments provide a method for network MRO analysis in the event of an MCG failure or RLF or CHO execution failure. Some embodiments provide a method for network MRO analysis in the event of an SCG failure or RLF or CPAC execution failure. Further details relating to embodiments of this application are illustrated in the following documents in conjunction with the accompanying drawings.

[0078] Figure 2 illustrates exemplary procedures for performing fault analysis according to several embodiments of this application. Exemplary procedure 200 in the embodiment of Figure 2 may be performed by a network node, for example, a source MN (S-MN), a candidate (target) MN, or a source SN (S-SN), for example, MN102 or SN103 shown in Figure 1. While the description focuses on network nodes, it should be understood that other devices may be configured to perform similar procedures to those in Figure 2.

[0079] In the exemplary procedure 200 shown in Figure 2, in operation 201, the network node may obtain cell information to recover from a failure when a failure occurs in one of the CHOs, including the CHO procedure, the CPAC procedure, and the target MCG and candidate SCG for the CPC / CPA procedure. In operation 202, the network node may perform an analysis of the failure.

[0080] In some embodiments, the network node is the source MN (the node managing the source PCell), and the source MN may perform at least one of the following actions in the event of, for example, an SCG failure or an RLF or CPAC execution failure. (1) Correct the list of CPAC candidate PSCells. (2) Send information to at least one candidate SN indicating that one or more CPAC candidate PSCells have been incorrectly selected. For example, the source MN may separately send one message to one or more candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected. The message may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message. For another example, the source MN may separately send one or more indicators to one or more candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected. This indicator may be included in an existing Xn message or X2 message, or in a newly transmitted Xn message or X2 message. (3) One or more candidate MNs indicate that at least one candidate SN should send information to indicate that one or more CPAC candidate PSCells have been incorrectly selected. For example, in an embodiment, the source MN may first send message X separately to one or more candidate MNs (optionally, the ID information of one or more candidate SNs may be included in message X, and message X may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message), and then one or more candidate MNs may send message Y separately to the corresponding candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected (message Y may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message). As another example, a source MN may separately send an indication P to one or more candidate SNs to inform them that one or more CPAC candidate PSCells have been incorrectly selected, and then one or more candidate MNs may separately send an indication Q to one or more candidate SNs to indicate that one or more CPAC candidate PSCells have been incorrectly selected (indicators P or Q may be included in an existing Xn or X2 message, or in a newly transmitted Xn or X2 message). (4) Optimize the set of CPAC execution conditions. (5) Send information to one or more candidate MNs indicating that the set of CPAC execution conditions is not properly configured.

[0081] In the embodiment, the cell is a PSCell for recovery from failure, and if the PSCell is not included in the list of CPAC candidate PSCells suggested or provided by the source MN, the source MN may modify the list of CPAC candidate PSCells.

[0082] In the embodiment, the cell is a PSCell for recovery from failure, and the PSCell is included in a list of CPAC candidate PSCells suggested or provided by the source MN, but not in another list of CPAC candidate PSCells selected or prepared by the candidate SN, (1) The source MN may send information to the candidate SN indicating that another list of CPAC candidate PSCells selected or provided by the candidate SN is unsuitable. For example, this information may be a message or indicate information contained within a message. For example, the source MN may send such information separately to one or more candidate SNs. (2) A source MN may indicate one or more candidate MNs to send information to a candidate SN indicating that another list of CPAC candidate PSCells selected or prepared by a candidate SN is inappropriate. For example, the source MN may first send a separate message to one or more candidate MNs indicating one or more candidate SNs, informing them that one or more CPAC candidate PSCells have been incorrectly selected (optionally, the ID information of one or more candidate SNs may be included in the message, and the message may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message), and then one or more candidate MNs may send a separate message to the corresponding candidate SN indicating that one or more CPAC candidate PSCells have been incorrectly selected (the message may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message). As another example, a source MN may separately send an indication to one or more candidate SNs to inform them that one or more CPAC candidate PSCells have been incorrectly selected, and then one or more candidate MNs may separately send an indication to one or more candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected (the indication may be included in an existing Xn or X2 message, or in a newly transmitted Xn or X2 message).

[0083] In the embodiment, the cell is a PSCell for recovery from failure, and if the PSCell is included in a list of CPAC candidate PSCells selected or prepared by a candidate SN, the source MN may optimize a set of CPAC execution conditions for the list of CPAC candidate PSCells, or the source MN may send information to one or more candidate MNs indicating that the set of CPAC execution conditions is improperly configured.

[0084] In some embodiments, the network node is the source MN, and the source MN may perform at least one of the following actions if, for example, an MCG failure or an RLF or CHO execution failure occurs. (1) Modify the list of candidate PCells for CHO. (2) Send information to at least one candidate MN indicating that one or more CHO candidate PCells have been incorrectly selected. For example, the source MN may separately send one message to one or more candidate MNs indicating that one or more CHO candidate PCells have been incorrectly selected, and the message may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message. For example, the source MN may separately send one indication to one or more candidate MNs indicating that one or more CHO candidate PCells have been incorrectly selected, and the indication may be contained within an existing Xn message or X2 message, or within a newly transmitted Xn message or X2 message. (3) Optimize the set of CHO execution conditions.

[0085] In the embodiment, the cell is a PCell for fault recovery, and if the PCell is not included in the list of CHO candidate PCells suggested or provided by the source MN, the source MN may modify the list of CHO candidate PCells.

[0086] In one embodiment, if the cell is a PCell for fault recovery, and the PCell is included in a list of CHO candidate PCells suggested or provided by the source MN, but not in another list of CHO candidate PCells selected or prepared by the candidate MN, the source MN may send information to the candidate MN indicating that the other list of CHO candidate PSCells selected or prepared by the candidate MN is not suitable. For example, this information may be a message or indicate information contained within a message. For example, the source MN may send such information separately to one or more candidate MNs.

[0087] In an embodiment, the cell is a PCell for fault recovery, and if the PCell is included in a list of CHO candidate PCells selected or prepared by a candidate MN, the source MN may optimize a set of CHO execution conditions for the list of CHO candidate PCells.

[0088] In some embodiments, the source MN can determine cell information, transmit cell information, or receive cell information. In embodiments, if the cell is a PCell for fault recovery, or if the cell is a PSCell for fault recovery, the source MN may obtain cell information, for example, in operation 201, by determining the cell information. Optionally, after determining the cell information, the source MN may transmit the cell information to, for example, one or more candidate MNs. In another embodiment, if the cell information is determined by another node (for example, one or more candidate MNs, or a source SN), the source MN may, for example, in operation 201, receive cell information from the other node (for example, one or more candidate MNs, or a source SN) to obtain the cell information.

[0089] In some embodiments, the source MN may transmit fault-related information (referred to as fault-related information #1 for clarity) to, for example, one or more candidate MNs or source SNs. In some other embodiments, the source MN may receive fault-related information from, for example, the source SN or at least one candidate MN or receiving network node (for example, a third-party node different from the source MN or source SN), and the fault-related information may be stored, generated, or transmitted by the UE.

[0090] In this embodiment, the fault-related information (for example, fault-related information #1) may include at least one of the following: (1) The type of the first execution condition or conditional event that is being met or triggered. For example, the type may be a CHO execution condition / CHO conditional event or a CPAC execution condition / CPAC conditional event. (2) The type of the second execution condition or conditional event that is being met or triggered. For example, the type may be a CHO execution condition / CHO conditional event or a CPAC execution condition / CPAC conditional event. (3) For example, if one or two CHO execution conditions of a candidate CHO PCell are already met or triggered, information indicating whether one or two CPAC execution conditions of a candidate CPAC PSCell are met or triggered. (4) For example, if one or two CPAC execution conditions of a CPAC candidate PSCell are first met or triggered, information indicating whether one or two CHO execution conditions of a CHO candidate PCell are met or triggered. (5) Cell information of the source PCell. For example, the cell information may include PCI, carrier frequency information (e.g., ARFCN), and / or CGI information (e.g., PLMN-Identity, cell identifier, and TrackingAreaCode). (6) Cell information of the affected PCell (7) Cell information of source PSCell (8) Cell information of the PSCell that has been affected

[0091] In the embodiment, if both the CHO execution conditions and the CPAC execution conditions are met, failure-related information #1 may include at least one of the following: (1) Information indicating whether a candidate PSCell whose CPAC execution conditions are met (i.e., a CPAC candidate PSCell whose CPAC execution conditions are met or triggered) is associated with a candidate PCell whose CHO execution conditions are met (i.e., a CHO candidate PCell whose CHO execution conditions are met or triggered). (2) For example, when one or two CPAC execution conditions of a CPAC candidate PSCell are met or triggered, information indicating whether the exit conditions of the candidate PCell whose CHO execution conditions have been met are met. (3) For example, when one or two CHO execution conditions of a CHO candidate PCell are met or triggered, information indicating whether the exit conditions of the candidate PSCell whose CPAC execution conditions have been met are met. (4) The time elapsed from when one or two CHO execution conditions of a CHO candidate PCell are met or triggered until one or two CPAC execution conditions of a CPAC candidate PSCell are met or triggered, or (5) The time elapsed between the time one or two CPAC execution conditions of a CPAC candidate PSCell are met or triggered and the time one or two CHO execution conditions of a CHO candidate PCell are met or triggered.

[0092] In some embodiments, the network node is a candidate MN (a node that manages one or more CHO candidate PCells), and the candidate MN may perform at least one of the following actions in the event of, for example, an SCG failure or an RLF or CPAC execution failure. (1) Correct the list of CPAC candidate PSCells. (2) Send information to at least one candidate SN indicating that one or more CPAC candidate PSCells have been incorrectly selected. For example, a candidate MN may separately send one message to one or more candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected. The message may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message. For another example, a source MN may separately send one or more indicators to one or more candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected. This indicator may be included in an existing Xn message or X2 message, or in a newly transmitted Xn message or X2 message. (3) Optimize the set of CPAC execution conditions. (4) Send information to the source MN indicating that the set of CPAC execution conditions is not configured correctly.

[0093] In the embodiment, the cell is a PSCell for recovery from failure, and if the PSCell is not included in the list of CPAC candidate PSCells suggested or provided by the candidate MN, the candidate MN may modify the list of CPAC candidate PSCells.

[0094] In an embodiment, if a cell is a PSCell for recovery from failure, and the PSCell is included in a list of CPAC candidate PSCells suggested or provided by a candidate MN, but not in another list of CPAC candidate PSCells selected or prepared by a candidate SN, the candidate MN may send information to the candidate SN indicating that the other list of CPAC candidate PSCells selected or prepared by the candidate SN is not suitable. For example, this information may be a message or indicate information contained within a message, and the candidate MN may send such information separately to one or more candidate SNs.

[0095] In the embodiment, the cell is a PSCell for recovery from failure, and if the PSCell is included in a list of CPAC candidate PSCells selected or prepared by the candidate SN, the candidate MN may optimize a set of CPAC execution conditions for the list of CPAC candidate PSCells, or the candidate MN may send information to the source MN indicating that the set of CPAC execution conditions is improperly configured.

[0096] In the embodiment, if, for example, an MCG failure or an RLF or CHO execution failure occurs, the candidate MN may perform at least one of the following actions: (1) The candidate MN receives information from the source MN indicating that at least one CHO candidate PCell has been incorrectly selected. For example, the candidate MN may receive a message from the source MN indicating that one or more CHO candidate PCells have been incorrectly selected. This message may be an existing Xn or X2 message, or a newly transmitted Xn or X2 message. For another example, the candidate MN may receive a display from the source MN indicating that one or more CHO candidate PCells have been incorrectly selected. This display may be contained within an existing Xn or X2 message, or within a newly transmitted Xn or X2 message. (2) Modify one or more CHO candidate PCells selected or prepared by the candidate MN.

[0097] In some embodiments, the candidate MN can determine cell information, transmit cell information, or receive cell information. In some embodiments, the candidate MN may obtain cell information, for example, in operation 201, by determining the cell information. Optionally, after determining the cell information, the candidate MN may transmit the cell information to the source MN. In another embodiment, if the cell information has been determined by another node (e.g., a source MN or source SN), the candidate MN may receive the cell information from the other node (e.g., a source MN or source SN) in order to obtain the cell information, for example, in operation 201.

[0098] In some embodiments, a candidate MN may receive fault-related information, such as fault-related information #1 described above, from a source MN. In some other embodiments, a candidate MN may receive fault-related information, such as fault-related information #1 described above, from one or more candidate SNs.

[0099] In some embodiments, the network node is the source SN (the node managing the source PSCell), and the source SN may perform at least one of the following actions in the event of, for example, an SCG failure or an RLF or CPAC execution failure. (1) Correct the list of CPAC candidate PSCells. (2) Send information to at least one candidate SN indicating that one or more CPAC candidate PSCells have been incorrectly selected. For example, the source SN may separately send one message to one or more candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected. The message may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message. For another example, the source SN may separately send one or more indicators indicating that one or more CPAC candidate PSCells have been incorrectly selected. This indicator may be included in an existing Xn message or X2 message, or in a newly transmitted Xn message or X2 message. (3) The source MN is instructed to send information to at least one candidate SN indicating that one or more CPAC candidate PSCells have been incorrectly selected. For example, the source SN may first send a message to the source MN indicating one or more candidate SNs to inform the source MN that one or more CPAC candidate PSCells have been incorrectly selected (optionally, the ID information of one or more candidate SNs may be included in the message, and the message may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message), and then the source MN may separately send messages to the corresponding candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected (the messages may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message). As another example, a source SN may send an indication to a source MN to inform one or more candidate SNs that one or more CPAC candidate PSCells have been incorrectly selected, and the source MN may then separately send indications to one or more candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected (the indications may be included in an existing Xn or X2 message, or in a newly transmitted Xn or X2 message). (4) Optimize the set of CPAC execution conditions.

[0100] In the embodiment, the cell is a PSCell for recovery from failure, and if the PSCell is not included in the list of CPAC candidate PSCells suggested or provided by the source SN, the source SN may modify the list of CPAC candidate PSCells.

[0101] In some embodiments, the cell is a PSCell for recovery from failure, and the PSCell is included in a list of CPAC candidate PSCells suggested or provided by the source SN, but not in another list of CPAC candidate PSCells selected or prepared by the candidate SN, (1) Source SN may send information to candidate SN indicating that another list of CPAC candidate PSCells selected or prepared by candidate SN is unsuitable. For example, this information may be a message or indicate information contained within a message, and source SN may send such information separately to one or more candidate SNs. (2) Source SN may indicate to Source MN that it send information to Candidate SN indicating that another list of CPAC candidate PSCells selected or prepared by Candidate SN is inappropriate. For example, Source SN may first send a message to Source MN indicating one or more Candidate SNs that one or more CPAC candidate PSCells have been incorrectly selected (optionally, the ID information of one or more Candidate SNs may be included in the message, and the message may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message), and then Source MN may separately send messages to the corresponding Candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected (the messages may be an existing Xn message or X2 message, or a newly transmitted Xn message or X2 message). As another example, a source SN may send a signal to a source MN indicating to one or more candidate SNs that one or more CPAC candidate PSCells have been incorrectly selected, and the source MN may then separately send signals to one or more candidate SNs indicating that one or more CPAC candidate PSCells have been incorrectly selected (the signals may be included in an existing Xn or X2 message, or in a newly transmitted Xn or X2 message).

[0102] In the embodiment, the cell is a PSCell for recovery from failure, and if the PSCell is included in a list of CPAC candidate PSCells selected or prepared by the candidate SN, the source SN may optimize a set of CPAC execution conditions for the list of CPAC candidate PSCells.

[0103] In some embodiments, the source SN can determine cell information, transmit cell information, or receive cell information. In some embodiments, the source SN may obtain cell information by determining cell information, for example, in operation 201. Optionally, after determining cell information, the source SN may transmit the cell information to, for example, the source MN. In another embodiment, if cell information is determined by the source MN, the source SN may receive cell information from the source MN in order to obtain cell information, for example, in operation 201.

[0104] In some embodiments, the source SN may receive fault-related information relating to a fault, for example, fault-related information #1 described above, from the source MN or from a receiving network node (for example, a third-party node different from the source MN or source SN). In embodiments, the fault may be an SCG fault, an MCG fault, an RLF, a CHO execution fault, or a CPAC execution fault.

[0105] In some embodiments, a failure may occur if configuration information regarding a CHO, including target MCG and candidate SCG for a CPC / CPA procedure, is configured for the user equipment (UE), but neither the CHO execution nor the CPA / CPC execution has been initiated for the UE prior to the failure. In embodiments, the failure is defined as a CHO that is too late, including target MCG and candidate SCG for CPC / CPA.

[0106] In some embodiments, the failure occurs in one of the following cases, namely Cases 1 to 7. (1) Case 1: At least one CHO execution condition is met for the CHO candidate PCell, but the CPA / CPC execution condition is met for the non-CPAC candidate PSCell. (2) Case 2: At least one CHO execution condition of a CHO candidate PCell is first met, and at least one CPA / CPC execution condition of a CPAC candidate PSCell is then met, but the CPAC candidate PSCell (e.g., a candidate PSCell that has met the CPAC execution condition) is not associated with a CHO candidate PCell (e.g., a candidate PCell that has met the CHO execution condition). (3) Case 3: The conditions for the departure of the CHO candidate PCell are met when at least one CHO execution condition of the CHO candidate PCell is first met, and then at least one CPA / CPC execution condition of the CPAC candidate PSCell is met. (4) Case 4: At least one CPAC execution condition is met for the CPAC candidate PSCell, but the CHO execution condition is met for the non-CHO candidate PCell. (5) Case 5: At least one CPAC execution condition of a CPAC candidate PSCell is first met, and then at least one CHO execution condition of a CHO candidate PCell is met, but the CHO candidate PCell (for example, a candidate PCell whose CHO execution condition is met) is not associated with a CPAC candidate PSCell (for example, a CPAC candidate PSCell whose CPAC execution condition is met). (6) Case 6: The eviction condition for the CPAC candidate PSCell is met when at least one CPAC execution condition for the CPAC candidate PSCell is first met, and then at least one CHO execution condition for the CHO candidate PCell is met. and (7) Case 7: The conditions for non-CHO implementation are met, and the conditions for non-CPAC implementation are met.

[0107] In some embodiments, a failure occurs in any of the following cases, namely cases A to C. (1) Case A: The CHO execution conditions and CPAC execution conditions are met, but the CPAC execution fails, or the SCG fails immediately after the successful completion of the CPAC execution. In Case A, when the CHO execution is successful, the UE may report failure-related information (e.g., failure-related information #1 described above) to the target MN, for example, via an SCG failure information message. (2) Case B: The CHO execution conditions and CPAC execution conditions are met, but the CHO execution fails, or the MCG failure occurs immediately after the successful completion of the CHO execution. In Case B, when the CPAC execution is successful, the UE may report failure-related information (e.g., failure-related information #1 described above) to the target SN, for example, via an MCG failure information message. (3) Case C: The CHO execution conditions and CPAC execution conditions are met, but the CHO execution fails, or the MCG fails immediately after the successful completion of the CHO execution, and the CPAC execution fails, or the SCG fails immediately after the successful completion of the CPAC execution. In Case C, the UE may report failure-related information (e.g., failure-related information #1 described above) related to the failures, for example, via RLF reporting.

[0108] In some embodiments of this application, in a CHO including a target MCG and a candidate SCG for a CPC / CPA procedure (i.e., a CHO with a candidate SCG procedure), a CHO execution may be triggered or initiated only when both the CHO execution conditions and their associated CPA / CPC execution conditions are met, and a CPAC (i.e., CPA or CPC) execution may be triggered or initiated only when its associated CHO execution conditions are met. In any of the examples 1 to 7 described above, a connection failure (e.g., at least one of an MCG failure, an SCG failure, or an RLF) may occur.

[0109] Examples 1-7 above can be classified as "too late CHO using candidate SCG", "too late CHO including target MCG and candidate SCG for CPA / CPA", or "too late CHO involving CPA / CPC execution". For example, the failure type definition for a failure occurring in a CHO including target MCG and candidate SCG for a CPC / CPA procedure may be "too late CHO using candidate SCG", "too late CHO involving CPA / CPC execution", or "too late CHO including target MCG and candidate SCG for CPA / CPA procedure", where a CHO including target MCG and candidate SCG for a CPC / CPA procedure is configured for the UE (or the UE receives configuration regarding a CHO using a candidate SCG procedure), but neither the CHO execution nor any CPA / CPC item is initiated or triggered for the UE prior to the connection failure.

[0110] Figure 3 shows an exemplary procedure performed by a candidate SN according to several embodiments of this application. The exemplary procedure 300 in the embodiment of Figure 3 may be performed by a candidate (target) SN (a node managing one or more CPAC candidate PSCells), for example, SN103 shown in Figure 1. While the candidate (target) SN is described, it should be understood that other devices may be configured to perform a similar method to that in Figure 3.

[0111] In the exemplary procedure 300 shown in Figure 3, candidate SN may perform at least one of operations 301 and 302. In operation 301, candidate SN may receive information indicating that one or more CPAC candidate PSCells have been incorrectly selected. This information may be received from source MN, one or more candidate MNs, or source SN. In operation 302, candidate SN may correct one or more CPAC candidate PSCells.

[0112] In some embodiments, if in operation 301 a PSCell for recovering from a failure is included in a list of CPAC candidate PSCells suggested or provided by the source MN, or by one or more candidate MNs, or by the source SN, but is not included in another list of CPAC candidate PSCells selected or prepared by the candidate SN, this information may be received from the source MN, one or more candidate MNs, or other source SNs. For example, the information in operation 301 may be a message, or it may indicate information contained within a message that one or more CPAC candidate PSCells have been incorrectly selected.

[0113] In some embodiments, this information is received when a failure occurs in a CHO (i.e., a CHO using a candidate SCG procedure) that includes a target MCG and candidate SCG for a CPAC procedure or a CPC / CPA procedure. For example, the failure may be an SCG failure, an RLF (Real-Level Failure), or a CPAC execution failure.

[0114] In some embodiments, a failure occurs when configuration information regarding a CHO, including a target MCG and candidate SCG for a CPC / CPA procedure, is configured to the UE, but neither the CHO execution nor the CPA / CPC execution has been initiated to the UE prior to the failure. For example, the failure is defined as "a CHO that is too late, including a target MCG and candidate SCG for CPC / CPA," or "a CHO that is too late, accompanied by a CPA / CPC execution," or "a CHO that is too late, using a candidate SCG." In some embodiments, the failure occurs in any one of the cases 1 to 7 described above in the embodiment of Figure 2. In other embodiments, the failure occurs in any one of the cases A to C described above in the embodiment of Figure 2.

[0115] In some embodiments, a candidate SN may receive fault-related information (e.g., fault-related information #1) from, for example, a UE, or a source MN, or a source SN, or at least one candidate MN, or a receiving network node (e.g., a third-party node different from the source MN or source SN). In some other embodiments, a candidate SN may transmit fault-related information (e.g., fault-related information #1) to, for example, a source MN, or a source SN, or at least one candidate MN. Fault-related information can be stored, generated, or transmitted by the UE.

[0116] Figure 4 shows exemplary procedures performed by a UE according to several embodiments of this application. Exemplary procedure 400 in the embodiment of Figure 4 may be performed by a UE, for example, UE101 shown in Figure 1. While the UE is described, it should be understood that other devices may be configured to perform similar methods to those in Figure 4.

[0117] In the exemplary procedure 400 shown in Figure 4, in operation 401, the UE may store fault-related information relating to a fault, for example, fault-related information #1 described above in the embodiment of Figure 2. The fault may occur in the CHO, which includes the target MCG and candidate SCG for the CPC / CPA procedure. In operation 402, the UE may transmit the fault-related information to, for example, the source MN, or (candidate) target MN, or the source SN, or (candidate) target SN, or the receiving network node.

[0118] In some embodiments, the failure may be an MCG failure, an SCG failure, an RLF, a CHO execution failure, or a CPAC execution failure.

[0119] In some embodiments, the UE may receive configuration information regarding the CHO, including the target MCG and candidate SCG for the CPC / CPA procedure. A failure may occur if the configuration information is received, but neither the CHO execution nor the CPA / CPC execution is initiated for the UE prior to the failure. For example, the failure may be defined as "too late CHO including the target MCG and candidate SCG for CPC / CPA", "too late CHO with CPA / CPC execution", or "too late CHO with candidate SCG". In some embodiments, the failure occurs in one of the cases 1-7 described above in the embodiment of Figure 2. In other embodiments, the failure occurs in one of the cases A-C described above in the embodiment of Figure 2.

[0120] Details described in all other embodiments of this application are applicable to the embodiments of Figures 2-4, which are carried out by the UE, source MN, candidate (target) MN, source SN, or candidate (target) SN. Furthermore, details described in the embodiments of Figures 2-4 are applicable to all other embodiments of this application. The order of operations in these exemplary procedures may be changed, and it will be understood by those skilled in the art that some of the operations in these exemplary procedures may be removed or modified without departing from the spirit and scope of this disclosure.

[0121] The following document describes specific embodiments 1 to 4 of the exemplary procedures shown and illustrated in Figures 2 to 4, or the aforementioned exemplary procedures performed by the UE, source MN, candidate (target) MN, source SN, or candidate (target) SN in failure cases (not limited to the aforementioned cases 1 to 7 and cases A to C).

[0122] According to embodiments 1 to 4, the UE and network node perform the following operations. For example, the UE may be UE101 as illustrated in Figure 1. The source MN (i.e., S-MN), target MN (i.e., T-MN), or candidate (target) MN may be MN102 as illustrated in Figure 1. The source SN (i.e., S-SN), target SN (i.e., T-SN), or candidate (target) SN may be SN103 as illustrated in Figure 1.

[0123] Embodiment 1 Embodiment 1 provides a solution for a UE to store or report failure-related information in failure cases (not limited to the aforementioned Examples 1-7 and Examples A-C). In Embodiment 1, in the event of a failure, the UE may store or report failure-related information (e.g., failure-related information #1 described above) to enable a network node to understand why a CHO including the target MCG and candidate SCG for a CPC / CPA procedure (i.e., a CHO using a candidate SCG procedure) was not successfully executed, or to help a network node understand whether or not to modify the configuration for this procedure (e.g., optimize the CHO execution conditions, CPAC execution conditions, list of CHO candidate PCells, or list of CPAC candidate PSCells), or how to do so. For example, at least one of the following failure-related information may be stored or reported by the UE: (1) Cell information of the source PCell. For example, in Embodiment 1, the cell information may include a physical cell identifier (PCI), carrier frequency information (e.g., absolute radio frequency channel number (ARFCN)), and / or cell global identifier information (CGI-info) (e.g., public land mobile network identifier (PLMN-Identity), cell identifier, and TrackingAreaCode). (2) Cell information of the PCell that experienced the failure (3) Cell information of the source PSCell. For example, the cell information of the source PSCell may be stored or reported when a failure occurs in Scenario 2 "CHO ​​using intra-SN CPC" or Scenario 3 "CHO ​​using inter-SN CPC", as described above. (4) Cell information of the PSCell that experienced the failure (5) The type of the first execution condition (or conditional event), if any, that is met or triggered. For example, the first execution condition (or conditional event) that is met or triggered is a CHO execution condition (or CHO conditional event) or a CPAC execution condition (or CPAC conditional event). (6) The type of any second execution condition (or conditional event) that is met or triggered, if any. For example, the second execution condition (or conditional event) that is met or triggered is a CPAC execution condition (or CPAC conditional event) or a CHO execution condition (or CHO conditional event). (7) Information indicating whether one or two CPAC execution conditions (or CPAC conditional events) of a CPAC candidate PSCell are met or triggered. For example, if one or more CHO execution conditions (or CHO conditional events) of a CHO candidate PCell are met or triggered first, this information may be a display. Furthermore, in some embodiments, If both the CHO execution conditions and the CPAC execution conditions are met, the UE further stores or reports information indicating whether a candidate PSCell that satisfies the CPAC execution conditions is associated with a candidate PCell that satisfies the CHO execution conditions, for example, this information may be an explicit indication or may be explicitly indicated by the cell information of the PCell and PSCell. If both the CHO execution conditions and the CPAC execution conditions are met, the UE further stores or reports information indicating whether the exit conditions for the candidate PCell whose CHO execution conditions have been met are also met (for example, when one or two CPAC execution conditions for the CPAC candidate PSCell are met or triggered). If both the CHO execution conditions and the CPAC execution conditions are met, the UE further stores or reports the duration between the two met or triggered execution conditions or conditional events, for example, (if the CHO execution conditions and CPAC execution conditions are associated, or if a candidate PSCell with a met CPAC execution condition is associated with a candidate PCell with a met CHO execution condition) the time elapsed from when one or two CHO execution conditions of the CHO candidate PCell are met or triggered until one or two CPAC execution conditions of the CPAC candidate PSCell are met or triggered. (8) Information indicating whether one or two CHO execution conditions (or CHO conditional events) of a CHO candidate PCell are met or triggered. For example, if one or two CPAC execution conditions (or CPAC conditional events) of a CPAC candidate PSCell are met or triggered first, this information may be a display. Furthermore, in some embodiments, If both the CHO execution conditions and the CPAC execution conditions are met, the UE further stores or reports information indicating whether a candidate PCell that satisfies the CHO execution conditions is associated with a candidate PSCell that satisfies the CPAC execution conditions, for example, this information may be an explicit indication or may be explicitly indicated by the cell information of the PCell and PSCell. If both the CHO execution conditions and the CPAC execution conditions are met, the UE further stores or reports information indicating whether the eviction conditions are met for the candidate PSCell whose CPAC execution conditions are met (for example, when one or two CHO execution conditions for a candidate CHO PCell are met or triggered). If both the CHO execution conditions and the CPAC execution conditions are met (if the CHO and CPAC execution conditions are associated, or if a candidate PCell whose CHO execution conditions are met is associated with a candidate PSCell whose CPAC execution conditions are met), the UE further stores or reports the duration between the two met or triggered execution conditions or conditional events, for example, the time elapsed between when one or two CPAC execution conditions of the CPAC candidate PSCell are met or triggered and when one or two CHO execution conditions of the CHO candidate PCell are met or triggered.

[0124] In Embodiment 1, at least one of the above-mentioned fault-related information may be reported by the UE via an MCG fault information message, an SCG fault information message, or an RLF report.

[0125] Embodiment 2 Embodiment 2 provides a solution for how network nodes perform MRO analysis on CHOs (i.e., CHOs using candidate SCG procedures) that include target MCGs and candidate SCGs for CPC / CPA procedures. Specifically, Embodiment 2 includes certain embodiments 2-1, 2-2, and 2-3 in different cases, as follows:

[0126] Embodiment 2-1 In Embodiment 2-1, for a CHO including a target MCG and candidate SCG for a CPC procedure, when an MCG failure or RLF or CHO execution failure occurs, the UE can send failure-related information to the S-SN, for example, via an MCG failure information message. The detailed failure-related information or information contained within the MCG failure information message may refer to the failure-related information #1 described above in Embodiment 1 (for example, in the embodiment of Figure 2). The S-SN may forward the failure-related information to the S-MN.

[0127] In Embodiment 2-1, for a CHO including a target MCG and candidate SCG for a CPA procedure, when an MCG failure or RLF or CHO execution failure occurs, the UE can send failure-related information to a receiving node (a third-party node different from the S-MN) via, for example, an RLF report, and the detailed failure-related information or information contained within the RLF report may refer to Embodiment 1 (for example, failure-related information #1 described above in the embodiment of Figure 2). The receiving node may forward the failure-related information to the S-MN, or to the S-SN, or to at least one candidate (target) MN, or to at least one candidate (target) SN.

[0128] In Embodiment 2-1, when a failure occurs or when S-MN receives failure-related information, S-MN can select a PCell to recover from the failure (for example, S-MN can select a PCell for high-speed MCG failure recovery), S-MN can perform root cause analysis, and for example, S-MN can perform the following actions: (1) If the selected PCell is not included in the list of CHO candidate PCells suggested, informed of, or provided by the S-MN to the candidate (target) MN managing the CHO candidate PCells, the S-MN shall know that the CHO candidate PCells suggested, informed of, or provided by the S-MN are inappropriate, and the S-MN may revise the list of CHO candidate PCells for MRO purposes. (2) If a selected PCell is included in a CHO candidate PCell suggested, informed of, or provided to the candidate (target) MN by the S-MN, but is not included in a CHO candidate PCell selected or prepared by the candidate (target) MN, the S-MN may understand that an incorrect CHO candidate PCell has been selected or prepared by the candidate (target) MN. If so, the S-MN may separately inform the candidate (target) MN that an incorrect CHO candidate PCell has been selected or prepared, for example, through a message or display. The candidate (target) MN may correct the CHO candidate PCell selected or prepared for the CHO, including the target MCG and candidate SCG for the CPC procedure. (3) If the selected PCell is included in a CHO candidate PCell selected or prepared by the candidate (target) MN, the S-MN may know that it has set inappropriate CHO execution conditions with respect to the CHO candidate PCell configured for the UE, or with respect to the CHO candidate PCell selected or prepared by the candidate (target) MN. The S-MN may optimize the CHO execution conditions for these CHO candidate PCells.

[0129] Embodiment 2-2 In Embodiment 2-2, for a CHO including a target MCG and candidate SCG for a CPC / CPA procedure, when an SCG failure or RLF or CPAC execution failure occurs, the UE can send failure-related information to the source MN (S-MN), for example, via an SCG failure information message, and the detailed failure-related information or information contained within the SCG failure information message may refer to Embodiment 1 (for example, failure-related information #1 described above in the embodiment of Figure 2).

[0130] Embodiment 2-2-1 Embodiment 2-2-1 assumes that one or more candidate (target) MNs suggest, inform, or provide CPAC candidate PSCells, and that the CPAC execution conditions for the CPAC candidate PSCells are determined or generated by one or more candidate (target) MNs. Candidate (target) SNs are nodes that manage one or more CPAC candidate PSCells. Candidate (target) MNs are nodes that manage one or more CHO candidate PCells.

[0131] In Embodiment 2-2-1, when a failure occurs or when the S-MN receives failure-related information, the S-MN can select a PSCell, for example, the S-MN can select an appropriate PSCell for SCG reconstruction. If the S-MN selects a PSCell, the S-MN can send the cell information of the selected PSCell to one or more candidate (target) MNs, or one candidate (target) MN can select a PSCell to recover from the failure, for example, the candidate (target) MN can select an appropriate PSCell for SCG reconstruction. If the candidate (target) MN selects a PSCell, the candidate (target) MN can send the cell information of the selected PSCell to the S-MN, and the S-MN can send the PSCell information for SCG reconstruction to the UE.

[0132] In Embodiment 2-2-1, the S-MN can perform an initial analysis and / or send fault-related information separately to one or more candidate (target) MNs, for example, via an existing X2 / Xn message or a newly transmitted X2 / Xn message. One or more candidate (target) MNs can send fault-related information separately to one or more candidate (target) SNs, for example, via an existing X2 / Xn message or a newly transmitted X2 / Xn message. In Embodiment 2-2-1, the S-MN can send fault-related information to the source SN, for example, via an existing X2 / Xn message or a newly transmitted X2 / Xn message.

[0133] In Embodiment 2-2-1, any one of the candidate (target) MNs within one or more candidate (target) MNs can perform root cause analysis, and for example, the candidate (target) MN can perform the following actions: (1) If the selected PSCell is not included in one or more CPAC candidate PSCells suggested, informed of, or provided by the candidate (target) MN to one or more candidate (target) SNs, the candidate (target) MN shall know that the CPAC candidate PSCell suggested, informed of, or provided by the candidate (target) MN itself is inappropriate. In that case, the candidate (target) MN may revise the list of CPAC candidate PSCells for MRO. (2) If a selected PSCell is included in a CPAC candidate PSCell suggested, informed of, or provided to one or more candidate (target) SNs by a candidate (target) MN, but is not included in a CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs, the candidate (target) MN will know that the list of CPAC candidate PSCells has been incorrectly selected or prepared by the candidate (target) SNs. If so, the candidate (target) MN may separately inform one or more candidate (target) SNs that the list of CPAC candidate PSCells has been incorrectly selected or prepared, for example, by message or display. In that case, one or more candidate (target) SNs may separately correct the CPAC candidate PSCells selected or prepared for the CHO, including the target MCG and candidate SCG for the CPC / CPA procedure. (3) If the selected PSCell is included in a CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs, the candidate (target) MN knows that the candidate (target) MN has set inappropriate CPAC execution conditions with respect to the CPAC candidate PSCell configured for the UE (or with respect to the CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs). In that case, the candidate (target) MN may optimize the CPAC execution conditions for these CPAC candidate PSCells.

[0134] Embodiment 2-2-2 Embodiment 2-2-2 assumes that the S-MN suggests, informs, or provides a CPAC candidate PSCell, and that the CPAC execution conditions for the CPAC candidate PSCell are determined or generated by the candidate (target) MN.

[0135] In Embodiment 2-2-2, when a failure occurs or when the S-MN receives failure-related information, the S-MN can select a PSCell to recover from the failure (for example, the S-MN can select an appropriate PSCell for SCG reconstruction). If the S-MN selects a PSCell, it can send the cell information of the selected PSCell to one or more candidate (target) MNs. Alternatively, a candidate (target) MN can select a PSCell to recover from a failure (for example, a candidate (target) MN can select an appropriate PSCell for SCG reconstruction). If a candidate (target) MN selects a PSCell, it can send the cell information of the selected PSCell to the S-MN, and the S-MN can send the PSCell information for SCG reconstruction to the UE.

[0136] In Embodiment 2-2-2, the S-MN can separately send fault-related information to one or more candidate (target) MNs, for example, via existing X2 / Xn messages or newly transmitted X2 / Xn messages. The one or more candidate (target) MNs can separately send fault-related information to one or more candidate (target) SNs, for example, via existing X2 / Xn messages or newly transmitted X2 / Xn messages.

[0137] In Embodiment 2-2-2, the S-MN can send fault-related information to the source SN, for example, via an existing X2 / Xn message or a newly transmitted X2 / Xn message.

[0138] In Embodiment 2-2-2, S-MN can perform root cause analysis, and for example, S-MN can perform the following operations. (1) If the selected PSCell is not included in the list of CPAC candidate PSCells suggested or provided by S-MN, S-MN will know that the list of CPAC candidate PSCells suggested or provided by S-MN is inappropriate. In that case, S-MN may revise the list of CPAC candidate PSCells for MRO. (2) If the selected PSCell is included in the CPAC candidate PSCells suggested or provided by the S-MN but is not included in the CPAC candidate PSCells selected or prepared by one or more candidate (target) SNs, the S-MN will know that one or more incorrect CPAC candidate PSCells have been selected or prepared by one or more candidate (target) SNs. If so, the S-MN may separately inform one or more candidate (target) SNs that one or more incorrect CPAC candidate PSCells have been selected or prepared, either directly (for example, via a message or display) or indirectly through one or more candidate (target) MNs (i.e., the S-MN may indicate one or more candidate (target) MNs to inform one or more candidate (target) SNs that one or more incorrect CPAC candidate PSCells have been selected or prepared), and optionally, the ID information of one or more candidate (target) SNs may be made known to one or more candidate (target) MNs by the S-MN. In that case, one of the candidate (target) MNs within one or more candidate (target) MNs may separately inform one or more candidate (target) SNs (for example, via a message or display, based on the ID information of one or more corresponding candidate (target) SNs) that one or more incorrect CPAC candidate PSCells have been selected or prepared. One or more candidate (target) SNs may separately correct the CPAC candidate PSCells selected or prepared for the CHO, including the target MCG and candidate SCG for the CPC / CPA procedure. (3) If the selected PSCell is included in a CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs, the S-MN knows that one or more candidate (target) MNs have set inappropriate CPAC execution conditions with respect to the CPAC candidate PSCell configured for the UE (or with respect to the CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs). The S-MN may separately inform one or more candidate (target) MNs that the CPAC execution conditions are set inappropriately (for example, by message or display). In that case, the candidate (target) MNs may separately optimize the CPAC execution conditions for these CPAC candidate PSCells.

[0139] Embodiment 2-2-3 Embodiment 2-2-3 assumes that S-MN suggests, informs, or provides a CPAC candidate PSCell, and that the CPAC execution conditions for the CPAC candidate PSCell are determined or generated by S-MN.

[0140] In Embodiment 2-2-3, when a failure occurs or when the S-MN receives failure-related information, the S-MN can select a PSCell to recover from the failure (for example, the S-MN can select a suitable PSCell for SCG reconstruction). If the S-MN selects a PSCell, it can send the cell information of the selected PSCell to one or more candidate (target) MNs. Alternatively, a candidate (target) MN can select a PSCell to recover from the failure (for example, a candidate (target) MN can select a suitable PSCell for SCG reconstruction). If a candidate (target) MN selects a PSCell, it can send the cell information of the selected PSCell to the S-MN, and the S-MN can send the PSCell information for SCG reconstruction to the UE.

[0141] In Embodiment 2-2-3, S-MN can separately send fault-related information to one or more candidate (target) MNs, for example, via existing X2 / Xn messages or newly transmitted X2 / Xn messages. One or more candidate (target) MNs can separately send fault-related information to one or more candidate (target) SNs, for example, via existing X2 / Xn messages or newly transmitted X2 / Xn messages. In Embodiment 2-2-3, S-MN can send fault-related information to source SN, for example, via existing X2 / Xn messages or newly transmitted X2 / Xn messages.

[0142] In Embodiment 2-2-3, S-MN can perform root cause analysis, and for example, S-MN can perform the following operations. (1) If the selected PSCell is not included in the list of CPAC candidate PSCells suggested or provided by S-MN, S-MN shall know that the list of CPAC candidate PSCells suggested or provided by S-MN is inappropriate, and S-MN may revise the list of CPAC candidate PSCells for MRO. (2) If a selected PSCell is included in a CPAC candidate PSCell suggested or provided by S-MN but is not included in a CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs, S-MN will know that the list of CPAC candidate PSCells has been incorrectly selected or prepared by one or more candidate (target) SNs. If so, S-MN may inform one or more candidate (target) SNs that the list of CPAC candidate PSCells has been incorrectly selected or prepared, either directly (e.g., via a message or display) or indirectly through one or more candidate (target) SNs (i.e., S-MN may separately indicate one or more candidate (target) MNs to inform one or more candidate (target) SNs that the list of CPAC candidate PSCells has been incorrectly selected or prepared, (e.g., via a message or display)). Optionally, the ID information of one or more candidate (target) SNs may be made known to one or more candidate (target) MNs by S-MN. In that case, one of the candidate (target) MNs within one or more candidate (target) MNs may separately inform one or more candidate (target) SNs (for example, via a message or display, based on the ID information of one or more corresponding candidate (target) SNs) that a list of CPAC candidate PSCells has been incorrectly selected or prepared. One or more candidate (target) SNs may separately correct the CPAC candidate PSCells selected or prepared for the CHO, including the target MCG and candidate SCG for the CPC / CPA procedure. (3) If a suitable PSCell is included in a CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs, the S-MN knows that it has set inappropriate CPAC execution conditions with respect to the CPAC candidate PSCell configured for the UE (or with respect to the CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs). In that case, the S-MN may optimize the CPAC execution conditions for these CPAC candidate PSCells.

[0143] Embodiment 2-2-4 Embodiment 2-2-4 assumes that one or more candidate (target) MNs suggest, inform, or provide CPAC candidate PSCells, and that the CPAC execution conditions for the CPAC candidate PSCells are determined or generated by the S-MN.

[0144] In Embodiment 2-2-4, when a failure occurs or when the S-MN receives failure-related information, the S-MN can select a PSCell (for example, the S-MN can select an appropriate PSCell for SCG reconstruction). If the S-MN selects a PSCell, it can send the cell information of the selected PSCell to one or more candidate (target) MNs. Alternatively, a candidate (target) MN can select a PSCell to recover from a failure (for example, a candidate (target) MN can select an appropriate PSCell for SCG reconstruction). If a candidate (target) MN selects a PSCell, it can send the cell information of the selected PSCell to the S-MN, and the S-MN can send the PSCell information for SCG reconstruction to the UE.

[0145] In Embodiment 2-2-4, the S-MN can perform an initial analysis and / or send fault-related information to one or more candidate (target) MNs, for example, via existing X2 / Xn messages or newly transmitted X2 / Xn messages. One or more candidate (target) MNs can separately send fault-related information to one or more candidate (target) SNs, for example, via existing X2 / Xn messages or newly transmitted X2 / Xn messages. In Embodiment 2-2-4, the S-MN can send fault-related information to the source SN, for example, via existing X2 / Xn messages or newly transmitted X2 / Xn messages.

[0146] In Embodiment 2-2-4, any one of the candidate (target) MNs within one or more candidate (target) MNs can perform root cause analysis, and for example, the candidate (target) MN can perform the following actions: (1) If the selected PSCell is not included in one or more CPAC candidate PSCells suggested, informed of, or provided by the candidate (target) MN to the candidate (target) SN, the candidate (target) MN will know that the CPAC candidate PSCell suggested, informed of, or provided by the candidate (target) MN is inappropriate. In that case, the candidate (target) MN may revise the list of CPAC candidate PSCells for MRO. (2) If the selected PSCell is included in a CPAC candidate PSCell suggested, informed of, or provided to one or more candidate (target) SNs by the candidate (target) MN, but is not included in a CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs, the candidate (target) MN will know that one or more incorrect CPAC candidate PSCells have been selected or prepared by the candidate (target) SNs. If so, the candidate (target) MN may separately inform one or more candidate (target) SNs, for example, by message or display, that one or more incorrect CPAC candidate PSCells have been selected or prepared. In that case, one or more candidate (target) SNs may separately correct the CPAC candidate PSCells selected or prepared for the CHO using the candidate SCG procedure. (3) If the selected PSCell is included in a CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs, the candidate (target) MN knows that the S-MN has set inappropriate CPAC execution conditions with respect to the CPAC candidate PSCell configured for the UE (or with respect to the CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs). The candidate (target) MN may inform the S-MN that the CPAC execution conditions are set inappropriately, for example, by message or display. In that case, the S-MN may optimize the CPAC execution conditions for these CPAC candidate PSCells.

[0147] Embodiment 2-3 In Embodiments 2-3, for a CHO including a target MCG and candidate SCG for a CPC / CPA procedure, when both an MCG failure and an SCG failure occur, the UE can send failure-related information to a network node (e.g., a node different from the source MN or source SN) via, for example, an RLF report. The detailed failure-related information or information contained within the RLF report may refer to Embodiment 1 (e.g., failure-related information #1 described above in the embodiment of Figure 2).

[0148] In Embodiment 2-3, a network node receiving fault-related information or an RLF report may forward the fault-related information or RLF report to an S-MN. The S-MN may forward the fault-related information or RLF report to an S-SN or one or more candidate (target) MNs. One or more candidate (target) MNs may forward the fault-related information or RLF report to one or more candidate (target) SNs.

[0149] Embodiment 3 Embodiment 3 provides a solution for MRO analysis for a CHO procedure. In a CHO procedure, if an RLF occurs before the CHO execution conditions are met, or if a CHO execution failure occurs, the receiving node (i.e., the node that receives the RLF report from the UE) sends the RLF report to the source node via a failure indication message. In a CHO procedure, if an RLF occurs immediately after a successful CHO execution from the source cell to the target cell, the receiving node (the node that receives the RLF report from the UE) sends the RLF report to the target node via a failure indication message, and the target node can then send the RLF report to the source node via a handover (HO) report message.

[0150] In Embodiment 3, when a failure occurs, the UE may select a cell to recover from the failure (for example, the UE may select a cell for CHO recovery), and the cell may be presented by the choCellId information element (IE) in 3GPP standard document TS38.331, which is used to indicate a candidate (target) cell for conditional handover included in the condRRCReconfig IE selected by the UE for CHO-based recovery while timer T311 is running, or, if the cell selected for the failure recovery / reestablishment attempt is not a candidate (target) cell for conditional reconfiguration, the cell may be presented by the reestablishmentCellId IE in 3GPP standard document TS38.331, which is used to indicate a cell on which a failure recovery / reestablishment attempt was made after the failure. Cell information for the cell to recover from the failure may be included in the RLF report. In Embodiment 3, the source node may perform root cause analysis, for example, the source node may perform the following actions: (1) If a cell for recovery from failure is not included in the CHO candidate PCell suggested or provided by the source node, the source node will know that the CHO candidate PCell suggested or provided by the source node is inappropriate. In that case, the source node may revise the list of CHO candidate PCells for MRO. (2) If a cell for recovering from a failure is included in a CHO candidate PCell suggested or provided by the source node, but is not included in a CHO candidate PCell selected or prepared by one or more candidate (target) nodes, the source node will know that the list of CHO candidate PCells has been incorrectly selected or prepared by one or more candidate (target) nodes. If so, the source node will separately inform one or more candidate (target) nodes, for example, by message or display, that one or more incorrect CHO candidate PCells have been selected or prepared. In that case, one or more candidate (target) nodes may correct the selected or prepared CHO candidate PCells. (3) If a cell for recovering from a failure is included in a CHO candidate PCell selected or prepared by one or more candidate (target) nodes, the source node will know that it has set inappropriate CHO execution conditions with respect to the candidate PCell configured for the UE (or the CHO candidate PCell selected or prepared by the candidate (target) node). In this case, the source node may optimize the CHO execution conditions with respect to these CHO candidate PCells.

[0151] Embodiment 4 Embodiment 4 provides an MRO analysis solution for a CPA procedure, a CPC procedure, or a CPAC procedure. In a CPA procedure, if a failure occurs in the CPA execution, or if an SCG failure occurs immediately after a successful CPA execution, the UE can send an SCG failure information message to the MN. In a CPC procedure, if an SCG failure occurs before the CPC execution conditions are met, or if a failure occurs in the CPC execution, or if an SCG failure occurs immediately after a successful CPC execution from a source PSCell to a target PSCell, the UE can send an SCG failure information message to the MN.

[0152] In Embodiment 4, in the case of a CPA procedure or a CPC procedure initiated by an MN, when a failure occurs or when the MN receives failure-related information in an SCG failure information message, the MN may select a PSCell to recover from the failure. For example, the MN may select an appropriate PSCell for SCG reconfiguration. The MN may perform a root cause analysis. For example, the MN may perform the following actions: (1) If the selected PSCell is not included in one or more candidate (target) SNs suggested or informed by the MN, the MN will know that the CPAC candidate PSCell suggested or informed by the MN is inappropriate, and the MN may revise the list of CPAC candidate PSCells. (2) If a selected PSCell is included in a list of CPAC candidate PSCells suggested or informed by the MN, but is not included in a list of CPAC candidate PSCells selected or prepared by one or more candidate (target) SNs, the MN will know that the list of CPAC candidate PSCells has been incorrectly selected or prepared by one or more candidate (target) SNs. If so, the MN may separately inform one or more candidate (target) SNs, for example, by message or display, that the list of CPAC candidate PSCells has been incorrectly selected or prepared, and one or more candidate (target) SNs may separately correct the selected or prepared CPAC candidate PSCells. (3) If the selected PSCell is included in a CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs, the MN will know that it has set inappropriate CPAC execution conditions with respect to the candidate PSCell configured for the UE (or with respect to the CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs), and the MN may optimize the CPAC execution conditions for these candidate PSCells.

[0153] In Embodiment 4, in the case of a CPC procedure initiated by SN, in one example, when a failure occurs or when MN receives failure-related information in an SCG failure information message, MN can select a PSCell to recover from the failure (for example, MN can select an appropriate PSCell for SCG reconstruction), and then MN can send the cell information of the selected PSCell to the source SN. In another example, when a failure occurs or when source SN receives failure-related information, source SN can select a PSCell to recover from the failure (for example, source SN can select an appropriate PSCell for SCG reconstruction), and then source SN can send the cell information of the selected PSCell to MN. In Embodiment 4, MN can perform an initial analysis and transfer SCG failure information to S-SN, and S-SN can perform a root cause analysis, for example S-SN can perform the following actions: (1) If the selected PSCell is not included in the list of CPAC candidate PSCells suggested or provided by S-SN, S-SN will know that the list of CPAC candidate PSCells suggested or provided by S-SN is inappropriate. In that case, S-SN may revise the list of CPAC candidate PSCells. (2) If a selected PSCell is included in a list of CPAC candidate PSCells suggested or provided by S-SN but is not included in a list of CPAC candidate PSCells selected or prepared by one or more candidate (target) SNs, S-SN will know that the list of CPAC candidate PSCells has been incorrectly selected or prepared by one or more candidate (target) SNs. If so, S-SN may separately inform one or more candidate (target) SNs that the list of CPAC candidate PSCells has been incorrectly selected or prepared, for example, directly via a message or display, or indirectly via an MN (i.e., S-SN may instruct an MN to inform one or more candidate (target) SNs that the list of CPAC candidate PSCells has been incorrectly selected or prepared, for example via a message or display), and optionally, the ID information of one or more candidate (target) SNs may be made known to the MN by S-SN. In that case, the MN can separately inform one or more candidate (target) SNs (for example, via a message or display, based on the ID information of one or more candidate (target) SNs) that a list of CPAC candidate PSCells has been incorrectly selected or prepared). One or more candidate (target) SNs can then individually correct the selected or prepared CPAC candidate PSCells. (3) If the selected PSCell is included in a CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs, the S-SN will know that it has set inappropriate CPAC execution conditions with respect to the candidate PSCell configured for the UE (or with respect to the CPAC candidate PSCell selected or prepared by one or more candidate (target) SNs), and the S-SN may optimize the CPAC execution conditions for these candidate PSCells.

[0154] Figure 5 shows a block diagram of an exemplary apparatus 500 according to some embodiments of the present disclosure. As shown in Figure 5, the apparatus 500 may include at least one processor 506 and at least one transceiver 502 coupled to the processor 506.

[0155] In this figure, elements such as at least one transceiver 502 and processor 506 are described singly, but unless a singular limitation is explicitly stated, plural is intended. In some embodiments of this application, the transceiver 502 may be divided into two devices, such as a receiving circuit and a transmitting circuit. In some embodiments of this application, the apparatus 500 may further include an input device, memory, and / or other components.

[0156] In some embodiments of this application, the apparatus 500 may be a UE, a source MN, a candidate MN, a source SN, or a candidate SN. The transceiver 502 and the processor 506 may interact with each other to perform operations relating to the UE, candidate MN, source MN, candidate SN, or source SN as described above, for example in any of Figures 1 to 4.

[0157] In some embodiments of this application, the apparatus 500 may further include at least one non-temporary computer-readable medium. For example, in some embodiments of this disclosure, the non-temporary computer-readable medium may store computer-executable instructions thereon causing the processor 506 to implement the methods relating to the UE as described above. For example, when executed, the computer-executable instructions cause the processor 506 to interact with the transceiver 502 to perform the operations relating to the UE, candidate MN, source MN, candidate SN, or source SN as described in Figures 1 to 4.

[0158] Those skilled in the art will understand that the operations or steps of the methods described in relation to the embodiments disclosed herein can be directly embodied in hardware, in software modules executed by a processor, or in combination of the two. Software modules may exist in the form of RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other storage medium known in the art. In addition, in some embodiments, the operations or steps of the methods may exist as one or a combination of code and / or instructions, or a set thereof, on a non-temporary computer-readable medium that can be incorporated into a computer program product.

[0159] While this disclosure is described using its specific embodiments, obviously many alternative, modified, and altered forms may be apparent to those skilled in the art. For example, various components of the embodiments may be replaced, added, or substituted in other embodiments. Furthermore, not all elements of each drawing are necessary for the operation of the disclosed embodiments. For example, a person skilled in the art of the disclosed embodiments may be able to teach or use the teachings of this disclosure by simply employing the elements of the independent claims. Accordingly, the embodiments of this disclosure described herein are intended to be illustrative, not limiting. Various modifications may be made without departing from the spirit and scope of this disclosure.

[0160] In this text, the terms “includes,” “including,” or any other variation thereof, are intended to encompass non-exclusive inclusions, such that a process, method, article, or apparatus containing a list of elements may include other elements not explicitly enumerated or specific to such process, method, article, or apparatus, rather than containing only those elements. Elements beginning with “a,” “an,” etc., do not, without further constraint, exclude the presence of additional identical elements in a process, method, article, or apparatus containing that element. The term “another” is defined as at least the following: Terms used herein, such as “having,” are defined as “including.” Expressions such as “A and / or B” or “at least one of A and B” may include any combination of any or all of the terms enumerated with the expression. For example, the expression “A and / or B” or “at least one of A and B” may include A, B, or both A and B. The terms "first," "second," etc., are used solely to clearly illustrate embodiments of this application and are not used to limit the substance of this application. [Explanation of Symbols]

[0161] 100 Wireless communication systems, dual connectivity systems 101 UE 102 MN 103 SN 500 devices 502 Transceiver 506 Processors

Claims

1. Network node, Transceiver and, A processor coupled to the transceiver and The processor includes, and the network node, Conditional Handover (CHO) Procedure Procedures for adding or modifying conditional primary secondary cell group cells (PSCells) (CPACs), and CHO including Target Master Cell Group (MCG) and Candidate Secondary Cell Group (SCG) for Conditional PSCell Modification / Conditional PSCell Addition (CPC / CPA) Procedures When a failure occurs in one of them, information about the cell to recover from the failure is obtained, To conduct an analysis of the aforementioned problems and A network node configured to perform the following actions.

2. The network node is a source master node (MN), and the processor provides the source MN with Correct the list of CPAC candidate PSCells. To transmit first information to at least one candidate SN indicating that one or more CPAC candidate PSCells have been incorrectly selected, To indicate one or more candidate MNs to transmit the first information to at least one candidate SN, Optimizing the set of CPAC execution conditions, or To transmit a second piece of information to the one or more candidate MN indicating that the set of CPAC execution conditions is improperly configured. A network node according to claim 1, configured to perform at least one of the following.

3. The network node is a source master node (MN), and the processor provides the source MN with Correct the list of CHO candidate PCells. Sending third information to at least one candidate MN to indicate that one or more CHO candidate PCells have been incorrectly selected, or Optimizing the set of CHO execution conditions. A network node according to claim 1, configured to perform at least one of the following.

4. The processor then provides the source MN with: To determine the information of the cell, Transmitting the information of the cell, or Receiving the information of the aforementioned cell A network node according to claim 2 or 3, configured to perform the following:

5. The processor then provides the source MN with: To transmit fault-related information related to the aforementioned fault, or Receiving the aforementioned fault-related information A network node according to claim 2, configured to perform the following:

6. The network node is a candidate master node (MN), and the processor is configured to provide the candidate MN with respect to the Correct the list of CPAC candidate PSCells. Sending a fourth piece of information to at least one candidate SN to indicate that one or more CPAC candidate PSCells have been incorrectly selected, Optimizing the set of CPAC execution conditions, or Send a fifth piece of information to the source MN indicating that the set of CPAC execution conditions is improperly configured. A network node according to claim 1, configured to perform at least one of the following.

7. The network node is a candidate master node (MN), and the processor is configured to provide the candidate MN with respect to the Receiving a sixth piece of information from the source MN indicating that at least one CHO candidate PCell has been incorrectly selected, or Modify one or more CHO candidate PCells selected by the aforementioned candidate MN. A network node according to claim 1, configured to perform at least one of the following.

8. The processor then selects the candidate MN, To determine the information of the cell, Transmitting the information of the cell, or Receiving the information of the aforementioned cell A network node according to claim 6 or 7, configured to perform the following:

9. The network node according to claim 6, wherein the processor is configured to cause the candidate MN to receive fault-related information related to the fault.

10. The network node is a source secondary node (SN), and the processor provides the source SN with Correct the list of CPAC candidate PSCells. Sending seventh pieces of information to at least one candidate SN to indicate that one or more CPAC candidate PSCells have been incorrectly selected, The source MN is instructed to transmit the seventh information to at least one candidate SN, or Optimizing the set of CPAC execution conditions A network node according to claim 1, configured to perform at least one of the following.

11. The processor then provides the source SN to To determine the information of the cell, Transmitting the information of the cell, or Receiving the information of the aforementioned cell A network node according to claim 10, configured to perform the following:

12. The network node according to claim 10, wherein the processor is configured to cause the source SN to receive fault-related information related to the fault.

13. The aforementioned fault-related information is The first type of execution condition that is satisfied, The second type of execution condition that is satisfied, Information indicating whether the CPAC execution conditions for the CPAC candidate PSCell are met. Information indicating whether the CHO execution conditions for the CHO candidate PCell are met. Information indicating whether a candidate PSCell that satisfies the CPAC execution conditions is associated with a candidate PCell that satisfies the CHO execution conditions. Information indicating whether the departure conditions for the candidate PCell whose CHO execution conditions have been met have been met, Information indicating whether the departure conditions for a candidate PSCell that has met the aforementioned CPAC execution conditions have been met, The time elapsed from when the CHO execution conditions are met until the CPAC execution conditions are met, or The time elapsed from when the CPAC execution condition is met until when the CHO execution condition is met. A network node according to any one of claims 5, 9, and 12, comprising at least one of the following.

14. Candidate secondary node (SN), Transceiver and, A processor coupled to the transceiver and The processor includes, and the candidate SN, Receiving information indicating that one or more conditional primary secondary cell group cell (PSCell) addition or modification (CPAC) candidate PSCells have been incorrectly selected, and such information is received from a source master node (MN), candidate MN, or source SN, or Modify the aforementioned one or more CPAC candidate PSCells. A candidate secondary node (SN) configured to perform at least one of the following actions.

15. User equipment (UE), Transceiver and, A processor coupled to the transceiver and The processor includes, and the UE, To store fault-related information relating to a fault, wherein the fault occurs in a conditional handover (CHO) involving a target master cell group (MCG) and a candidate secondary cell group (SCG) for a conditional primary secondary cell group (PSCell) change / conditional PSCell add (CPC / CPA) procedure, To transmit the aforementioned fault-related information and User equipment (UE) configured to perform the following actions.

Images