WO2024065419A1 - Procédés et appareils d'une procédure cho avec des scgs candidats - Google Patents

Procédés et appareils d'une procédure cho avec des scgs candidats Download PDF

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Publication number
WO2024065419A1
WO2024065419A1 PCT/CN2022/122704 CN2022122704W WO2024065419A1 WO 2024065419 A1 WO2024065419 A1 WO 2024065419A1 CN 2022122704 W CN2022122704 W CN 2022122704W WO 2024065419 A1 WO2024065419 A1 WO 2024065419A1
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WIPO (PCT)
Prior art keywords
candidate
target
cho
pcell
pscell
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PCT/CN2022/122704
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English (en)
Inventor
Le Yan
Mingzeng Dai
Lianhai WU
Congchi ZHANG
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Lenovo (Beijing) Limited
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Priority to PCT/CN2022/122704 priority Critical patent/WO2024065419A1/fr
Publication of WO2024065419A1 publication Critical patent/WO2024065419A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/34—Reselection control
    • H04W36/36—Reselection control by user or terminal equipment
    • H04W36/362—Conditional handover
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link
    • H04W36/0069—Transmission or use of information for re-establishing the radio link in case of dual connectivity, e.g. decoupled uplink/downlink
    • H04W36/00692—Transmission or use of information for re-establishing the radio link in case of dual connectivity, e.g. decoupled uplink/downlink using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO]

Definitions

  • Embodiments of the present application generally relate to methods and apparatuses for a conditional handover (CHO) with candidate secondary cell groups (SCG) s procedure.
  • CHO conditional handover
  • SCG candidate secondary cell groups
  • a UE with multiple transceivers may be configured to utilize resources provided by two different nodes connected via non-ideal backhauls.
  • one node may provide new radio (NR) access and the other one node may provide either evolved-universal mobile telecommunication system (UMTS) terrestrial radio access (UTRA) (E-UTRA) or NR access.
  • NR new radio
  • UTRA evolved-universal mobile telecommunication system
  • E-UTRA evolved-universal mobile telecommunication system
  • One node may act as a master node (MN) and the other node may act as a secondary node (SN) .
  • MN and SN are connected via a network interface (for example, a Xn or X2 interface as specified in 3rd Generation Partnership Project (3GPP) standard documents) , and at least the MN is connected to the core network.
  • 3GPP 3rd Generation Partnership Project
  • a conditional PSCell addition (CPA) procedure and a conditional PSCell change (CPC) procedure are supported.
  • a CPAC procedure is a CPA procedure or a CPC procedure.
  • a CPAC procedure is defined as a PSCell addition or a PSCell change that is executed by a UE when execution condition (s) configured for CPAC is met or fulfilled.
  • a UE starts evaluating the CPAC execution condition (s) upon receiving CPAC related configuration information, and stops evaluating the CPAC execution condition (s) once a PSCell addition and/or change procedure is triggered or executed, the PSCell addition and/or change procedure is triggered or executed means that when CPAC execution condition (s) of a candidate PSCell is satisfied or fulfilled, the UE decides the candidate PSCell as a target PSCell, and performs a PSCell addition or change procedure with the target PSCell, e.g. the UE performs a RA procedure towards the target PSCell.
  • a CHO is defined as a handover that is executed by a user equipment (UE) when one or more handover or CHO execution conditions are met.
  • the UE starts evaluating the one or more CHO execution conditions upon receiving the CHO related configuration information (e.g. including one or more configurations associated candidate PCell (s) and one or more CHO execution conditions) , and stops evaluating the CHO execution conditions during the CHO execution or once the one or more CHO execution conditions are met or fulfilled.
  • the CHO execution means that when CHO execution condition (s) of a candidate PCell is satisfied or fulfilled, the UE decides the candidate PCell as a target PCell, and performs a PCell change or handover procedure with the target PCell, e.g. the UE performs a RA procedure towards the target PCell.
  • the UE includes a transceiver and a processor coupled to the transceiver; and the processor is configured to: receive, via the transceiver from a source master node (MN) , at least one of: a first set of configurations for at least one candidate primary cell (PCell) , a second set of configurations for at least one candidate primary secondary cell group cell (PSCell) , a set of conditional handover (CHO) execution conditions for the at least one candidate PCell, or a set of conditional PSCell addition or change (CPAC) execution conditions for the at least one candidate PSCell; and in response to at least one of: occurrence of a source secondary cell group (SCG) failure, occurrence of a source master cell group (MCG) failure, unfulfillment of the set of CHO execution conditions, unfulfillment of the set of CPAC execution conditions, or occurrence of a failure during a CHO execution, perform one of: initiating a failure
  • MN source master node
  • MN source master node
  • the second set of configurations is associated with the first set of configurations; or the second set of configurations is encapsulated in the first set of configurations.
  • the at least one candidate PSCell is associated with the at least one candidate PCell.
  • the processor of the UE is configured to: receive the first set of configurations, wherein the second set of configurations is encapsulated in the first set of configurations; or receive the first set of configurations and the second set of configurations, respectively.
  • the set of CPAC execution conditions is associated with the set of CHO execution conditions, or the set of CPAC execution conditions is encapsulated in the set of CHO execution conditions.
  • the processor of the UE is configured to: receive the set of CHO execution conditions, wherein the set of CPAC execution conditions is encapsulated in the set of CHO execution conditions; or receive the set of CHO execution conditions and the set of CPAC execution conditions, respectively.
  • the processor of the UE in response to initiating the failure recovery procedure, is configured to: perform a cell selection operation to select a cell; in response to the selected cell belonging to the at least one candidate PCell, determines the selected cell as a target PCell, and perform a handover operation to the target PCell; or in response to the selected cell not belonging to the at least one candidate PCell, perform a radio resource control (RRC) reestablishment procedure.
  • RRC radio resource control
  • the processor of the UE in response to selecting the selected cell belonging to the at least one candidate PCell or in response to performing the handover operation to the target PCell or in response to successful completion of the handover operation to the target PCell, is configured to perform at least one of: selecting a candidate PSCell associated with the target PCell, and adding the selected candidate PSCell as a target PSCell; or evaluating one or more CPAC execution conditions for at least one candidate PSCell associated with the target PCell within the set of CPAC execution conditions.
  • the processor of the UE in response to evaluating the one or more CPAC execution conditions, is configured to: in response to fulfillment of a CPAC execution condition of a candidate PSCell within the at least one candidate PSCell associated with the target PCell, add the candidate PSCell as the target PSCell; or in response to unfulfillment of the one or more CPAC execution conditions, transmit, via the transceiver to a target master node (MN) managing the target PCell, at least one of: information for indicating the unfulfillment of the one or more CPAC execution conditions; or information related to at least one of failure events.
  • MN target master node
  • the at least one of failure events includes: the occurrence of the source SCG failure; the occurrence of the source MCG failure; the unfulfillment of the set of CHO execution conditions; the unfulfillment of the set of CPAC execution conditions; or the occurrence of the failure during the CHO execution.
  • the processor of the UE is configured to: concurrently evaluate the set of CHO execution conditions and the set of CPAC execution conditions; or firstly evaluate the set of CHO execution conditions, and in response to fulfillment of a CHO execution condition for a candidate PCell within the set of CHO execution conditions, evaluate a CPAC execution condition for a candidate PSCell associated with the CHO-execution-condition-fulfilled candidate PCell within the set of CPAC execution conditions.
  • the processor of the UE in response to concurrently evaluating the set of CHO execution conditions and the set of CPAC execution conditions and in response to the set of CPAC execution conditions for the at least one candidate PSCell being fulfilled before the set of CHO execution conditions for the at least one candidate PCell being fulfilled, the processor of the UE is configured to: continue a CHO execution condition evaluation for at least one candidate PCell associated with a CPAC-execution-condition-fulfilled candidate PSCell within the at least one candidate PSCell until the occurrence of the source SCG failure or until reaching first configured time duration.
  • the first configured time duration is configured by a target MN or a source MN.
  • the processor of the UE in response to concurrently evaluating the CHO execution condition and the CPAC execution condition and in response to the set of CHO execution conditions for the at least one candidate PCell being fulfilled before the set of CPAC execution conditions for the at least one candidate PSCell being fulfilled, the processor of the UE is configured to: continue a CPAC execution condition evaluation for at least one candidate PSCell associated with a CHO-execution-condition-fulfilled candidate PCell within the at least one candidate PCell until the occurrence of the failure during the CHO execution or until reaching second configured time duration.
  • the second configured time duration is configured by a target MN or a target secondary node (SN) .
  • the processor of the UE is configured to receive at least one of the first configured time duration or the second configured time duration via the transceiver from a source MN.
  • Some embodiments of the present application also provide a target master node (MN) .
  • the target MN includes a transceiver and a processor coupled to the transceiver; and the processor is configured to receive information related to at least one of failure events via the transceiver from a user equipment (UE) , wherein the at least one of failure events includes: occurrence of a source secondary cell group (SCG) failure; occurrence of a source master cell group (MCG) failure; unfulfillment of a set of conditional handover (CHO) execution conditions for at least one candidate primary cell (PCell) ; unfulfillment of a set of conditional primary secondary cell group cell (PSCell) addition or change (CPAC) execution conditions for at least one candidate PCell; or occurrence of a failure during a CHO execution.
  • SCG source secondary cell group
  • MCG source master cell group
  • CHO conditional handover
  • PCell candidate primary cell
  • PSCell conditional primary secondary cell group cell
  • CPAC conditional primary secondary cell
  • the processor of the target MN is configured to transmit the information related to the at least one of failure events via the transceiver to a source MN.
  • the processor of the target MN is configured to: generate first configured time duration, wherein the first configured time duration is used by the UE during the UE continuing a CHO execution condition evaluation for one or more candidate PCells associated with a CPAC-execution-condition-fulfilled candidate PSCell within at least one candidate PCell configured to the UE; and transmit the first configured time duration via the transceiver to a source MN.
  • the processor of the target MN is configured to: generate second configured time duration, wherein the second configured time duration is used by the UE during the UE continuing CPAC execution condition evaluation for one or more candidate PSCells associated with a CHO-execution-condition-fulfilled candidate PCell within at least one candidate PSCell configured to the UE; and transmit the second configured time duration via the transceiver to a source MN.
  • the processor of the target MN is configured to: receive second configured time duration via the transceiver from a target secondary node (SN) , wherein the second configured time duration is used by the UE during the UE continuing CPAC execution condition evaluation for one or more candidate PSCells associated with a CHO-execution-condition-fulfilled candidate PCell within at least one candidate PSCell configured to the UE; and transmit the second configured time duration via the transceiver to a source MN.
  • SN target secondary node
  • the source MN includes a transceiver and a processor coupled to the transceiver; and the processor is configured to transmit, via the transceiver to a user equipment (UE) , at least one of: a first set of configurations for at least one candidate primary cell (PCell) , a second set of configurations for at least one candidate primary secondary cell group cell (PSCell) , a set of conditional handover (CHO) execution conditions for the at least one candidate PCell, or a set of conditional PSCell addition or change (CPAC) execution conditions for the at least one candidate PSCell.
  • UE user equipment
  • the processor of the source MN is configured to transmit, via the transceiver to the UE, a first configured time duration, wherein the first configured time duration is used by the UE during CHO execution condition evaluation for one or more candidate PCells associated with a CPAC-execution-condition-fulfilled candidate PSCell within at least one candidate PCell configured to the UE.
  • the processor of the source MN is configured to: generate the first configured time duration; or receive the first configured time duration via the transceiver from a target MN.
  • the processor of the source MN is configured to transmit, via the transceiver to the UE, a second configured time duration, wherein the second configured time duration is used by the UE during the UE continuing CPAC execution condition evaluation for one or more candidate PSCells associated with a CHO-execution-condition-fulfilled candidate PCell within at least one candidate PSCell configured to the UE.
  • the processor of the source MN is configured to receive the second configured time duration via the transceiver from a target MN, and wherein the second configured time duration is generated by the target MN or a target secondary node (SN) .
  • Some embodiments of the present application also provide a target secondary node (SN) .
  • the target SN includes a transceiver and a processor coupled to the transceiver; and the processor is configured to: generate a configured time duration, wherein the configured time duration is used by a user equipment (UE) during the UE continuing a conditional primary secondary cell group cell (PSCell) addition or change (CPAC) execution condition evaluation for one or more candidate PSCells associated with a conditional handover-execution-condition-fulfilled candidate primary cell (PCell) within at least one candidate PSCell configured to the UE; and transmit the configured time duration via the transceiver to a target master node (MN) .
  • MN target master node
  • Some embodiments of the present application provide a method performed by a UE.
  • the method includes: receiving, from a source master node (MN) , at least one of: a first set of configurations for at least one candidate primary cell (PCell) , a second set of configurations for at least one candidate primary secondary cell group cell (PSCell) , a set of conditional handover (CHO) execution conditions for the at least one candidate PCell, or a set of conditional PSCell addition or change (CPAC) execution conditions for the at least one candidate PSCell; and in response to at least one of: occurrence of a source secondary cell group (SCG) failure, occurrence of a source master cell group (MCG) failure, unfulfillment of the set of CHO execution conditions, unfulfillment of the set of CPAC execution conditions, or occurrence of a failure during a CHO execution, performing one of: initiating a failure recovery procedure; initiating a CHO execution; and continuing the CHO execution.
  • MN source master node
  • Some embodiments of the present application provide a method performed by a target MN.
  • the method includes: receiving information related to at least one of failure events from a user equipment (UE) , wherein the at least one of failure events includes: occurrence of a source secondary cell group (SCG) failure; occurrence of the source master cell group (MCG) failure; unfulfillment of a set of conditional handover (CHO) execution conditions for at least one candidate primary cell (PCell) ; unfulfillment of a set of conditional primary secondary cell group cell (PSCell) addition or change (CPAC) execution conditions for at least one candidate PCell; or occurrence of a failure during an CHO execution.
  • SCG source secondary cell group
  • MCG source master cell group
  • CHO conditional handover
  • PCell candidate primary cell
  • PSCell conditional primary secondary cell group cell
  • CPAC conditional primary secondary cell group
  • Some embodiments of the present application provide a method performed by a source MN.
  • the method includes: transmitting, to a user equipment (UE) , at least one of: a first set of configurations for at least one candidate primary cell (PCell) , a second set of configurations for at least one candidate primary secondary cell group cell (PSCell) , a set of conditional handover (CHO) execution conditions for the at least one candidate PCell, or a set of conditional PSCell addition or change (CPAC) execution conditions for the at least one candidate PSCell.
  • UE user equipment
  • CHO conditional handover
  • CPAC conditional PSCell addition or change
  • Some embodiments of the present application provide a method performed by a target SN.
  • the method includes: generating a configured time duration, wherein the configured time duration is used by a user equipment (UE) during the UE continuing a conditional primary secondary cell group cell (PSCell) addition or change (CPAC) execution condition evaluation for one or more candidate PSCells associated with a conditional handover-execution-condition-fulfilled candidate primary cell (PCell) within at least one candidate PSCell configured to the UE; and transmitting the configured time duration to a target master node (MN) .
  • PSCell conditional primary secondary cell group cell
  • CPAC conditional handover-execution-condition-fulfilled candidate primary cell
  • MN target master node
  • Some embodiments of the present application provide an apparatus for wireless communications.
  • the apparatus comprises: a non-transitory computer-readable medium having stored thereon computer-executable instructions; a receiving circuitry; a transmitting circuitry; and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry and the transmitting circuitry, wherein the computer-executable instructions cause the processor to implement the abovementioned method performed by a UE or a network node (asource MN, a target MN, a source SN, or a target SN) .
  • a network node as source MN, a target MN, a source SN, or a target SN
  • FIG. 1 illustrates a schematic diagram of a wireless communication system in accordance with some embodiments of the present application.
  • FIG. 2 illustrates an exemplary flowchart performed by a UE in accordance with some embodiments of the present application.
  • FIG. 3 illustrates an exemplary flowchart performed by a target SN in accordance with some embodiments of the present application.
  • FIG. 4 illustrates a block diagram of an exemplary apparatus in accordance with some embodiments of the present disclosure.
  • FIG. 1 illustrates a schematic diagram of a wireless communication system in accordance with some embodiments of the present application.
  • 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.
  • the dual connectivity system 100 in FIG. 1 includes one shown UE 101, one shown MN 102, and one shown SN 103 for illustrative purpose.
  • a specific number of UEs 101, MNs 102, and SNs 103 are depicted in FIG. 1, it is contemplated that any number of UEs 101, MNs 102, and SNs 103 may be included in the wireless communication system 100.
  • UE 101 may be connected to MN 102 and SN 103 via a network interface, for example, the Uu interface as specified in 3GPP standard documents.
  • MN 102 and SN 103 may be connected with each other via a network interface, for example, the Xn interface as specified in 3GPP standard documents for NR-NR DC or NGEN-DC or NE-DC, or X2 interface as specified in 3GPP standard documents for EN-DC.
  • MN 102 may be connected to the core network via a network interface (not shown in FIG. 1) .
  • UE 102 may be configured to utilize resources provided by MN 102 and SN 103 to perform data transmission.
  • MN 102 may refer to a radio access node that provides a control plane connection to the core network.
  • MN 102 in the E-UTRA-NR Dual Connectivity (EN-DC) scenario, MN 102 may be an eNB.
  • MN 102 in the next generation E-UTRA-NR Dual Connectivity (NGEN-DC) scenario, MN 102 may be an ng-eNB.
  • NGEN-DC next generation E-UTRA-NR Dual Connectivity
  • MN 102 may be an ng-eNB.
  • MN 102 in the NR-E-UTRA Dual Connectivity (NE-DC) scenario or the NR-NR Dual Connectivity (NR-DC) scenario, MN 102 may be a gNB.
  • MN 102 may be associated with a master cell group (MCG) .
  • MCG may refer to a group of serving cells associated with MN 102, and may include a primary cell (PCell) and optionally one or more secondary cells (SCells) of the MCG.
  • PCell primary cell
  • SCells secondary cells
  • the PCell may provide a control plane connection to UE 101.
  • SN 103 may refer to a radio access node without a control plane connection to the core network but providing additional resources to UE 101.
  • SN 103 in the EN-DC scenario, may be an en-gNB.
  • SN 103 in the NE-DC scenario, may be a ng-eNB.
  • SN 103 in the NR-DC scenario or the NGEN-DC scenario, may be a gNB.
  • the SN 103 may be associated with a secondary cell group (SCG) .
  • SCG may refer to a group of serving cells associated with SN 103, and may include a primary secondary cell (PSCell) and optionally one or more secondary cells (SCells) .
  • PSCell primary secondary cell
  • SCells secondary cells
  • the PCell of the MCG and the PSCell of the SCG may also be referred to as a special cell (SpCell) .
  • UE 101 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (PDAs) , tablet computers, smart televisions (e.g., televisions connected to the Internet) , set-top boxes, game consoles, security systems (including security cameras) , vehicle on-board computers, network devices (e.g., routers, switches, and modems) , or the like.
  • PDAs personal digital assistants
  • UE 101 may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiving circuitry, or any other device that is capable of sending and receiving communication signals on a wireless network.
  • UE 101 may include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, UE 101 may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art.
  • wearable devices such as smart watches, fitness bands, optical head-mounted displays, or the like.
  • UE 101 may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art.
  • a CHO is executed by a UE when handover or CHO execution condition (s) are met or satisfied or fulfilled.
  • a CHO execution may be an operation that the UE decides the CHO-execution-condition-fulfilled candidate PCell as a target PCell, and performs a PCell change or handover with the target PCell, e.g. the UE performs a RA procedure towards the target PCell.
  • a UE starts evaluating the CHO execution condition (s) upon receiving the CHO configuration, and stops evaluating the CHO execution condition during the CHO execution once the CHO execution condition (s) is met or fulfilled.
  • CHO configuration contains the configuration for CHO candidate PCell (s) generated by the candidate BS (s) (e.g. candidate target MN (s) ) and CHO execution condition (s) generated by the source BS (e.g. source MN) .
  • a CPAC is executed by a UE when one or more handover or CPAC execution condition (s) are met or satisfied or fulfilled.
  • CPAC execution condition (s) of a candidate PSCell is satisfied or fulfilled, a CPAC execution is performed
  • “a CPAC execution” may be an operation that the UE decides the CPAC-execution-condition-fulfilled candidate PSCell as a target PSCell, and performs a PSCell addition or change with the target PSCell, e.g. the UE performs a RA procedure towards the target PSCell.
  • a UE starts evaluating the CPAC execution condition (s) upon receiving the CPAC configuration, and stops evaluating the CPAC execution condition during the CPAC execution once the CPAC execution condition (s) is met or fulfilled.
  • CPAC configuration i.e. CPA or CPC configuration
  • the preparation and execution phase of the CHO procedure is performed without involvement of the 5G Core Network (5GC) ; i.e., preparation messages are directly exchanged between BSs.
  • 5GC 5G Core Network
  • the release of the resources at the source BS during the conditional handover completion phase is triggered by the target BS, wherein neither the access and mobility management function (AMF) nor the user plane function UPF changes.
  • AMF access and mobility management function
  • An inter-MN handover with or without MN initiated SN change is used to transfer UE context data from a source MN to a target MN while the UE context at the SN is kept or moved to another SN.
  • the target MN decides whether to keep or change the SN (or release the SN) .
  • intra-RAT intra radio access technology
  • an M-NG-RAN node initiates the procedure by sending the S-NODE ADDITION REQUEST message to the S-NG-RAN node.
  • the S-NG-RAN node shall consider that the S-NG-RAN node Addition Preparation procedure has been triggered as part of a conditional handover. It may use the Source M-NG-RAN node ID IE and the Source M-NG-RAN node UE XnAP ID IE to identify other active S-NG-RAN node Addition Preparations related to this UE. If the Estimated Arrival Probability IE is contained in the CHO Information SN Addition IE included in the S-NODE ADDITION REQUEST message, the S-NG-RAN node may use the information to allocate necessary resources for the UE.
  • an M-NG-RAN node initiates the procedure by sending the S-NODE MODIFICATION REQUEST message to the S-NG-RAN node.
  • the S-NG-RAN node shall consider that the M-NG-RAN node initiated S-NG-RAN node Modification Preparation procedure has been triggered as part of a conditional handover.
  • the S-NG-RAN node may use the information to allocate necessary resources for the UE.
  • one object for mobility enhancements in 3GPP Rel-18 is to specify a CHO with candidate SCGs procedure (i.e., to specify CHO including candidate target MCG (s) and candidate target SCG (s) for CPC or CPA) .
  • a CHO with candidate SCGs procedure may also be named as “a CHO related to candidate SCGs procedure” or “a CHO procedure related to candidate SCGs” or the like. For instance, below scenario can be considered for a CHO with candidate SCGs procedure:
  • Scenario 1 “CHO with intra-SN CPC” : for example, CHO from source PCell 1 with SCG 1 in SN 1 to candidate (target) PCell 2 with candidate (target) SCG (s) in the same SN 1. That is, in Scenario 1, PCell is changed, PSCell is changed but SN is not changed.
  • Scenario 2 “CHO with inter-SN CPC” : CHO from source PCell 1 with SN 1 to candidate (target) PCell 2 with candidate (target) SN (s) other than SN 1. That is, in Scenario 2, PCell is changed, and SN is changed.
  • Scenario 3 “CHO with CPA” : CHO from single-connectivity to a NR-DC connection, e.g., CHO from source PCell 1 to candidate (target) PCell 2 with candidate target SN (s) . That is, in Scenario 3, single-connectivity is changed to dual-connectivity.
  • CPC or CPA configuration may be associated with CHO configuration, which may be named as “CHO configuration referring to CPC or CPA configuration” or the like.
  • CPC or CPA configuration may be encapsulated in CHO configuration, which may be named as “CHO configuration including CPC or CPA configuration” or the like.
  • CHO configuration referring to or including CPC or CPA configuration can be configured by a network node for a CHO with candidate SCGs procedure.
  • the configuration (s) for a CHO with candidate SCGs procedure i.e., CHO configuration referring to or including CPC or CPA configuration
  • the CHO evaluation and the CPC or CPA evaluation may be concurrent or sequential in following two ways:
  • Way 1 concurrent CHO evaluation and CPC or CPA evaluation, e.g., the UE starts evaluation of CHO execution condition (s) for candidate (target) PCells and CPAC execution condition (s) for candidate (target) PSCells at the same time (when receiving the configuration for a CHO with candidate SCGs procedure) .
  • (2) Way 2 sequential CHO evaluation and CPC or CPA evaluation, e.g., the UE first starts evaluation of CHO execution condition (s) for candidate (target) PCells, when CHO execution condition (s) of a candidate (target) PCell is fulfilled, the UE evaluates CPAC execution condition (s) of candidate (target) PSCell (s) .
  • a UE may detect a RLF, e.g. a source SCG failure, a target MCG failure and/or a source MCG failure, issues of how to handle such failure cases have been be solved.
  • a RLF e.g. a source SCG failure, a target MCG failure and/or a source MCG failure
  • Embodiments of the present disclosure aim to solve such issues in the abovementioned scenarios.
  • a UE may continue CHO execution condition evaluation of one or more candidate (target) PCell associated with the CPAC-execution-condition-fulfilled candidate (target) PSCell until a source SCG failure happens, a source MCG failure happens, or until a configured time duration is reached.
  • the UE may continue CPAC execution condition evaluation of one or more candidate (target) PSCell associated with the CHO-execution-condition-fulfilled candidate (target) PCell until a CHO execution failure happens, a source SCG failure happens, or until a configured time duration is reached.
  • the UE may perform a specific failure recovery mechanism, i.e., the UE may perform cell selection (e.g., also the UE keeps the latest received configuration for a CHO with candidate SCGs procedure) .
  • the UE performs a handover operation to the target PCell (i.e., the selected candidate (target) PCell)
  • the handover operation may an operation that the UE performs a RA procedure towards the target PCell or the UE access to the target PCell.
  • CHO execution condition (s) being not fulfilled means that within the at least one candidate PCell (s) configured for a CHO with candidate SCGs procedure, there is no candidate PCell whose corresponding CHO execution condition (s) is fulfilled.
  • CPAC execution condition (s) being not fulfilled means that within the at least one candidate PSCell (s) configured for a CHO with candidate SCGs procedure, there is no candidate PSCell whose corresponding CPAC execution condition (s) is fulfilled.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell (for example, the UE performs a RA procedure towards the target PSCell or the UE access to the target PSCell) .
  • the UE may evaluate CPAC execution condition (s) for a least one candidate (target) PSCells which are associated with the target PCell.
  • CPAC execution condition (s) of a candidate (target) PSCell If CPAC execution condition (s) of a candidate (target) PSCell is fulfilled, the UE may also add the candidate (target) PSCell as the target PSCell. Otherwise, the UE may indicate CPAC execution condition (s) is not fulfilled and/or corresponding failure events to a target MN managing the target PCell, and the target MN may decide later action, e.g., whether or how to reconfigure HO/CHO/CPA/CPC/PA/PC. Otherwise, in some other embodiments, the UE performs RRC re-establishment.
  • the UE may perform or continue CHO execution if CHO execution condition (s) of at least one candidate (target) PCell is fulfilled, “CHO execution” may be an operation that the UE performs a PCell change or handover with the target PCell (the target PCell is a candidate PCell whose CHO execution condition (s) is fulfilled) .
  • CHO execution may be an operation that the UE performs a PCell change or handover with the target PCell (the target PCell is a candidate PCell whose CHO execution condition (s) is fulfilled) .
  • the UE may indicate corresponding failure events to the target PCell or target MN.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell. Or, the UE may evaluate the CPAC execution condition (s) for one or more candidate (target) PSCell (s) which is associated with the target PCell. For instance, if CPAC execution condition (s) of a candidate (target) PSCell is fulfilled, the UE may also add the candidate (target) PSCell as the target PSCell. Otherwise, the UE may indicate CPAC execution condition (s) is not fulfilled and/or corresponding failure events to target PCell or target MN. In these embodiments, if CHO execution fails, the UE may perform the specific failure recovery mechanism as stated above.
  • FIG. 2 illustrates an exemplary procedure of performing a CHO procedure to in accordance with some embodiments of the present application.
  • the exemplary procedure 200 in the embodiments of FIG. 2 may be performed by a UE, e.g., UE 101 as shown in FIG. 1.
  • a UE e.g., UE 101 as shown in FIG. 1.
  • FIG. 2 illustrates an exemplary procedure of performing a CHO procedure to in accordance with some embodiments of the present application.
  • the exemplary procedure 200 in the embodiments of FIG. 2 may be performed by a UE, e.g., UE 101 as shown in FIG. 1.
  • UE 101 e.g., UE 101 as shown in FIG. 1.
  • FIG. 2 illustrates an exemplary procedure of performing a CHO procedure to in accordance with some embodiments of the present application.
  • FIG. 2 illustrates an exemplary procedure of performing a CHO procedure to in accordance with some embodiments of the present application.
  • a UE may receive, from a source MN, at least one of:
  • a set of configurations for at least one candidate PCell The at least one candidate PCell is denoted as candidate PCell (s) #1 for simplicity. There is one or more candidate PCell (s) within candidate PCell (s) #1 that configured for the CHO with candidate SCGs procedure, including cell information e.g. CG and/or PCI and/or ARFCN.
  • the set of configurations for candidate PCell (s) #1 is denoted as configuration set#1 for simplicity.
  • Each candidate PCell within the at least one candidate PCell may have its corresponding configurations, including L1 and/or L2 and/or L3 parameters.
  • a set of configurations for at least one candidate PSCell The at least one candidate PSCell is denoted as candidate PSCell (s) #1 for simplicity. There is one or more candidate PSCell (s) within candidate PSCell (s) #1 that configured for the CHO with candidate SCGs procedure, including cell information e.g. CG and/or PCI and/or ARFCN.
  • the set of configurations for candidate PSCell (s) #1 is denoted as configuration set#2 for simplicity.
  • Each candidate PSCell within the at least one candidate PSCell may have its corresponding configurations, including L1 and/or L2 and/or L3 parameters.
  • a set of CHO execution conditions for candidate PCell (s) #1 may have its corresponding CHO execution condition (s) , including A3 and/or A5 conditional events.
  • CHO execution condition (s) for different candidate PCells within candidate PCell (s) #1 may be the same or different.
  • the set of CHO execution conditions for candidate PCell (s) #1 at least includes one CHO execution condition.
  • a set of CPAC execution conditions for candidate PSCell (s) #1 may have its corresponding CPAC execution condition (s) , including A3, A4, A5, B1, B2 and/or B3 conditional events.
  • CPAC execution condition (s) for different candidate PSCells within candidate PSCell (s) #1 may be the same or different.
  • the set of CPAC execution conditions for candidate PSCell (s) #1 at least includes one CPAC execution condition.
  • candidate PSCell (s) #1 is associated with candidate PCell (s) #1, which means that for one candidate PSCell within the candidate PSCell (s) #1, there may be one or more candidate PCells within the candidate PCell (s) #1 which is associated with the candidate PSCell; or means that for one candidate PCell within the candidate PCell (s) #1, there may be one or more candidate PSCells within the candidate PSCell (s) #1 which is associated with the candidate PCell.
  • At least one candidate PSCell within candidate PSCell (s) #1 may be associated with a candidate PCell within candidate PCell (s) #1, or at least one candidate PCell within candidate PCell (s) #1 may be associated with a candidate PSCell within candidate PSCell (s) #1, which means that the candidate PSCell (s) and the associated candidate PCell (s) can serve the UE simultaneously as a DC scenario.
  • the set of configurations for at least one candidate PCell is associated with the set of configurations for at least one candidate PSCell, or the set of configurations for at least one candidate PSCell is associated with the set of configurations for at least one candidate PCell.
  • the set of configurations for at least one candidate PCell is encapsulated in the set of configurations for at least one candidate PSCell, or the set of configurations for at least one candidate PSCell is encapsulated in the set of configurations for at least one candidate PCell.
  • the UE receives the set of configurations for at least one candidate PCell, wherein the set of configurations for at least one candidate PSCell is included or encapsulated in the set of configurations for at least one candidate PCell. In some other embodiments, the UE receives the set of configurations for at least one candidate PCell and the set of configurations for at least one candidate PSCell respectively, which means that the set of configurations for at least one candidate PCell and the set of configurations for at least one candidate PSCell are provided to the UE in a parallel way.
  • configuration set#2 is associated with configuration set#1.
  • configuration set#2 is encapsulated in configuration set#1, or configuration set#2 and configuration set#1 are configured to the UE in a parallel way.
  • the UE may receive configuration set#1, wherein configuration set#2 is encapsulated in configuration set#1.
  • the UE may receive configuration set#1 and configuration set#2, respectively.
  • the UE may perform one of: initiating a failure recovery procedure; initiating a CHO execution; and continuing the CHO execution.
  • the unfulfillment of the set of CHO execution conditions means that any CHO execution condition within the set of CHO execution conditions is not fulfilled.
  • the unfulfillment of the set of CPAC execution conditions means that any CPAC execution condition within the set of CPAC execution conditions is not fulfilled.
  • CHO execution may be an operation that the UE performs a PCell change or handover with the target PCell (the target PCell is a candidate PCell whose CHO execution condition (s) is fulfilled) , e.g. the UE performs a RA procedure towards the target PCell or the UE access to the target PCell.
  • the set of CPAC execution conditions is associated with the set of CHO execution conditions. In some other embodiments, the set of CPAC execution conditions is included or encapsulated in the set of CHO execution conditions.
  • the set of CPAC execution conditions and the set of CHO execution conditions are provided to the UE in a cascaded way, or the set of CPAC execution conditions and the set of CHO execution conditions are provided to the UE in a parallel way.
  • the UE may receive the set of CHO execution conditions, wherein the set of CPAC execution conditions is encapsulated in the set of CHO execution conditions. In another embodiment, the UE may receive the set of CHO execution conditions and the set of CPAC execution conditions, respectively.
  • the UE in response to initiating the failure recovery procedure, may perform a cell selection operation to select a cell.
  • the network e.g. source MN
  • the UE may receive an indication from network (e.g.
  • source MN that indicates the UE to initiate the failure recovery procedure, in response to occurrence of a source SCG failure, occurrence of a source MCG failure, unfulfillment of the set of CHO execution conditions, unfulfillment of the set of CPAC execution conditions, and/or occurrence of a failure during a CHO execution.
  • candidate PCell e.g.
  • the UE may determine the selected cell as a target PCell, and perform a handover operation to the target PCell (the handover operation may an operation that the UE performs a RA procedure towards the target PCell or the UE access to the target PCell) .
  • the UE may perform an RRC reestablishment procedure.
  • the cell selected by the UE is a candidate PCell, the UE performs the handover operation including that the UE applies configurations of the target PCell (i.e. the selected candidate PCell) which are included in configuration set#1, and access to the target PCell.
  • the UE in response to selecting the selected cell belonging to the candidate PCell (s) that configured for a CHO with candidate SCGs procedure (e.g. which belongs to candidate PCell (s) #1) ” or “in response to performing the handover operation to the target PCell” or “in response to successful completion of the handover operation to the target PCell” , the UE may perform at least one of:
  • the UE may select any candidate PSCell or select the best cell and/or beam quality candidate PSCell which is associated with the target PCell, the UE determines the selected candidate PSCell as the target PSCell, and the UE may perform a RA procedure towards the target PSCell or the UE access to the target PSCell.
  • the network e.g.
  • the source MN sends an indication to the UE to indicate the UE to select a candidate PSCell which is associated with the target PCell, “in response to selecting the selected cell belonging to the candidate PCell (s) that configured for a CHO with candidate SCGs procedure (e.g. which belongs to candidate PCell (s) #1) ” or “in response to performing the handover operation to the target PCell” or “in response to successful completion of the handover operation to the target PCell” .
  • the UE may receive an indication from network (e.g.
  • source MN that indicates the UE to select a candidate PSCell which is associated with the target PCell, “in response to selecting the selected cell belonging to the candidate PCell (s) that configured for a CHO with candidate SCGs procedure (e.g. which belongs to candidate PCell (s) #1) ” or “in response to performing the handover operation to the target PCell” or “in response to successful completion of the handover operation to the target PCell” .
  • the network e.g.
  • the source MN sends an indication to the UE to indicate the UE to perform CPAC execution condition evaluation of any candidate PSCell which is configured for the CHO with candidate SCGs procedure, or perform CPAC execution condition evaluation of any candidate PSCell which is associated with the target PCell, “in response to selecting the selected cell belonging to the candidate PCell (s) that configured for a CHO with candidate SCGs procedure (e.g. which belongs to candidate PCell (s) #1) ” or “in response to performing the handover operation to the target PCell” or “in response to successful completion of the handover operation to the target PCell” .
  • the UE may receive an indication from network (e.g.
  • the UE in response to evaluating the one or more CPAC execution condition (s) : in response to fulfillment of a CPAC execution condition of a candidate PSCell within the at least one candidate PSCell associated with the target PCell, the UE may add the candidate PSCell as the target PSCell (e.g.
  • the UE may perform a RA procedure towards the target PSCell or the UE access to the target PSCell)
  • the added target PSCell may be any CPAC-execution-condition-fulfilled candidate PSCell which is associated with the target PCell, or a best cell/beam quality CPAC-execution-condition-fulfilled candidate PSCell which is associated with the target PCell; or in response to unfulfillment of the one or more CPAC execution condition (s) , the UE may transmit “information for indicating the unfulfillment of the one or more CPAC execution condition (s) ” and/or “information related to at least one of failure events” to a target MN managing the target PCell.
  • the unfulfillment of the one or more CPAC execution condition (s) means that none CPAC execution condition is fulfilled.
  • the at least one of failure events includes: occurrence of the source SCG failure; occurrence of the source MCG failure; unfulfillment of the set of CHO execution conditions; unfulfillment of the set of CPAC execution conditions; or occurrence of the failure during the CHO execution.
  • the UE may concurrently evaluate the set of CHO execution conditions and the set of CPAC execution conditions. In some other embodiments, the UE may firstly evaluate the set of CHO execution conditions, and then, in response to fulfillment of CHO execution condition (s) for a candidate PCell within the set of CHO execution conditions, the UE may evaluate CPAC execution condition (s) for “any candidate PSCell which is associated with the CHO-execution-condition-fulfilled candidate PCell” within the set of CPAC execution conditions.
  • the UE may concurrently evaluate the set of CHO execution conditions and the set of CPAC execution conditions. In some other embodiments, the UE may firstly evaluate the set of CPAC execution conditions, and then, in response to fulfillment of CPAC execution condition (s) for a candidate PSCell within the set of CPAC execution conditions, the UE may evaluate CHO execution condition (s) for “any candidate PCell which is associated with the CPAC-execution-condition-fulfilled candidate PSCell” within the set of CHO execution conditions.
  • the UE may perform or continue a CHO execution condition evaluation for at least one candidate PCell which is associated with “aCPAC-execution-condition-fulfilled candidate PSCell within PSCell (s) #1” until occurrence of the source SCG failure or source MCG failure or until reaching configured time duration (denoted as time duration#1 for simplicity) .
  • time duration#1 may be configured by a target MN or a source MN.
  • the set of CPAC execution conditions for candidate PSCell (s) #1 being fulfilled before the set of CHO execution conditions for candidate PCell (s) #1 being fulfilled means that, within candidate PSCell (s) #1, there may be one or more candidate PSCell whose corresponding CPAC execution condition (s) is fulfilled, but heretofore, within candidate PCell (s) #1, none candidate PCell’s corresponding CHO execution condition (s) is fulfilled, or “the set of CPAC execution conditions for PSCell (s) #1 being fulfilled before the set of CHO execution conditions for PCell (s) #1 being fulfilled” means that at least one CPAC execution condition, instead of all the CPAC execution conditions, within the set of CPAC execution conditions for PSCell (s) #1 is fulfilled before the set of CHO execution conditions for PCell (s) #1 being fulfilled.
  • the UE may perform or continue a CPAC execution condition evaluation for “at least one candidate PSCell which is associated with a CHO-execution-condition-fulfilled candidate PCell” within PCell (s) #1 until occurrence of a failure during the CHO execution or the source SCG failure or until reaching configured time duration (denoted as time duration#2 for simplicity) .
  • time duration#2 may be configured by a target MN or a target SN.
  • the UE may receive time duration#1 and/or time duration#2 from a source MN.
  • “the set of CHO execution conditions for candidate PCell (s) #1 being fulfilled before the set of CPAC execution conditions for candidate PSCell (s) #1 being fulfilled” means that, within candidate PCell (s) #1, there may be one or more candidate PCell whose corresponding CHO execution condition (s) is fulfilled, but heretofore, within candidate PSCell (s) #1, none candidate PSCell’s corresponding CPAC execution condition (s) is fulfilled, or “the set of CHO execution conditions for PCell (s) #1 being fulfilled before the set of CPAC execution conditions for PSCell (s) #1 being fulfilled” means that at least one CHO execution condition, instead of all the CHO execution conditions, within the set of CHO execution conditions for PCell (s) #1 is fulfilled before the set of CPAC execution conditions for PSCell (s) #1 being fulfilled.
  • Some other embodiments of the present application provide an exemplary procedure of a CHO procedure performed by a target MN or a candidate (target) MN, e.g., MN 102 as shown in FIG. 1.
  • a target MN manages a CHO-execution-condition-fulfilled target PCell
  • a candidate (target) MN or a candidate target MN manages a candidate (target) PCell which is configured for a CHO with candidate SCGs.
  • the target MN or the candidate (target) MN may receive information related to at least one of failure events from a UE (e.g., UE 101 as shown in FIG. 1) .
  • the at least one of failure events may include: occurrence of a source SCG failure; occurrence of a source MCG failure; unfulfillment of a set of CHO execution conditions for at least one candidate PCell; unfulfillment of a set of CPAC execution conditions for at least one candidate PCell; or occurrence of a failure during a CHO execution.
  • the unfulfillment of the set of CHO execution conditions means that none CHO execution condition within the set of CHO execution conditions is fulfilled.
  • the unfulfillment of the set of CPAC execution conditions means that none CPAC execution condition within the set of CPAC execution conditions is fulfilled.
  • the target MN or the candidate (target) MN may transmit the information related to the at least one of failure events to a source MN.
  • the target MN or the candidate (target) MN may generate configured time duration which is used by the UE during the UE continuing a CHO execution condition evaluation for “one or more candidate PCells associated with a CPAC-execution-condition-fulfilled candidate PSCell” within at least one candidate PCell configured to the UE. Then, the target MN or the candidate (target) MN may transmit the configured time duration to a source MN.
  • the target MN or the candidate (target) MN may generate another configured time duration (denoted as time duration#2 for simplicity) which is used by the UE during the UE continuing CPAC execution condition evaluation for “one or more candidate PSCells associated with a CHO-execution-condition-fulfilled candidate PCell” within at least one candidate PSCell configured to the UE. Then, the target MN or the candidate (target) MN may transmit the generated time duration#2 to a source MN.
  • time duration#2 for simplicity
  • the target MN or the candidate (target) MN may receive, from a target SN, time duration#2 which is used by the UE during the UE continuing CPAC execution condition evaluation for “one or more candidate PSCells associated with a CHO-execution-condition-fulfilled candidate PCell” within at least one candidate PSCell configured to the UE. Then, the target MN or the candidate (target) MN may transmit time duration#2 to a source MN.
  • Some additional embodiments of the present application provide an exemplary procedure of a CHO procedure performed by a source MN, e.g., a source MN not shown in FIG. 1.
  • a source MN may transmit, to a UE, at least one of: a set of configurations for at least one candidate PCell, a set of configurations for at least one candidate PSCell, a set of CHO execution conditions for the at least one candidate PCell, or a set of CPAC execution conditions for the at least one candidate PSCell.
  • the source MN may transmit, to the UE, configured time duration (denoted as time duration#1 for simplicity) which is used by the UE during CHO execution condition evaluation for “one or more candidate PCells associated with a CPAC-execution-condition-fulfilled candidate PSCell” within at least one candidate PCell configured to the UE.
  • the source MN may generate time duration#1 or receive time duration#1 from a target MN or a candidate (target) MN.
  • the source MN may transmit, to the UE, another configured time duration (denoted as time duration#2 for simplicity) which is used by the UE during the UE continuing CPAC execution condition evaluation for “one or more candidate PSCells associated with a CHO-execution-condition-fulfilled candidate PCell” within at least one candidate PSCell configured to the UE.
  • the source MN may receive, from a target MN or a candidate (target) MN, time duration#2 which is generated by the target MN, the candidate (target) MN, or a target SN or a candidate (target) SN.
  • a target SN manages a CPAC-execution-condition-fulfilled target PSCell.
  • a candidate (target) SN or a candidate target SN manages a candidate (target) PSCell which is configured for a CHO with candidate SCGs.
  • FIG. 3 illustrates an exemplary procedure of receiving failure related information in accordance with some embodiments of the present application.
  • the exemplary procedure 300 in the embodiments of FIG. 3 may be performed by a target SN or a candidate (target) SN, e.g., SN 103 as shown in FIG. 1.
  • a target SN or a candidate (target) SN e.g., SN 103 as shown in FIG. 1.
  • a target SN or a candidate (target) SN may generate configured time duration (denoted as time duration#1 for simplicity) , which is used by a UE during the UE continuing a CPAC execution condition evaluation for “one or more candidate PSCells associated with a conditional handover-execution-condition-fulfilled candidate PCell” within at least one candidate PSCell configured to the UE.
  • the target SN or the candidate (target) SN may transmit time duration#1 to a target MN or a candidate (target) MN.
  • a UE and network nodes perform following operations.
  • the UE may be UE 101 as shown and illustrated in FIG. 1.
  • a target MN or a candidate (target) MN may be MN 102 as shown and illustrated in FIG. 1.
  • a target SN or a candidate (target) SN may be SN 103 as shown and illustrated in FIG. 1.
  • a source MN may be a MN not shown in FIG. 1.
  • a target SN or a candidate (target) SN may be a SN as shown and illustrated in FIG. 1.
  • failure recovery for a CHO with candidate SCGs procedure may be defined as below.
  • a UE performs cell selection (e.g., meanwhile, the UE keeps the latest received configuration for a CHO with candidate SCGs procedure) .
  • failure recovery for a CHO with candidate SCGs procedure may be defined as below.
  • the UE may perform handover to the target PCell (i.e., perform a RACH procedure towards the selected candidate (target) PCell, or access to the selected candidate (target) PCell) .
  • the target PCell i.e., perform a RACH procedure towards the selected candidate (target) PCell, or access to the selected candidate (target) PCell.
  • Option 1 There may be following two options, Option 1 and Option 2.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell, e.g., when the target PCell is selected or handover (HO) to the selected PCell or target PCell is successful.
  • the any candidate (target) PSCell or the best candidate (target) PSCell is included in the configuration for a CHO with candidate SCGs procedure or included in the set of configurations for at least one candidate PSCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to select a candidate PSCell which is associated with the target PCell, e.g., when the target PCell is selected or handover/access to the selected PCell or target PCell is successful.
  • network e.g. source MN
  • the UE may evaluate CPAC execution condition (s) of one or more candidate (target) PSCells which are associated with the target PCell, e.g., when the candidate (target) PCell is selected or HO/access to the selected PCell or target PCell is successful.
  • the one or more candidate (target) PSCells are included in the configuration for a CHO with candidate SCGs procedure or included in the set of configurations for at least one candidate PSCell.
  • the UE may receive an indication from network (e.g.
  • source MN that indicates the UE to evaluate CPAC execution condition (s) of one or more candidate (target) PSCells which are associated with the target PCell, e.g., when the candidate (target) PCell is selected or HO/access to the selected PCell or target PCell is successful.
  • the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • the UE may decide any one within the more than one candidate (target) PSCells as the target PSCell, or the best one (e.g. best cell/beam quality) within the more than one candidate (target) PSCells as the target PSCell, and then, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • the UE indicates that CPAC execution condition (s) is not met to a target MN, e.g. indicates that CPAC execution condition (s) of one or more candidate (target) PSCells which are associated with the target PCell is not fulfilled.
  • the target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PSCell Addition (PA) or Primary Cell (PC) .
  • the target MN may decide a subsequent action related to reconfiguring the CPAC procedure.
  • the UE may perform an RRC re-establishment procedure.
  • Embodiment 1 provides a solution for Way 1 as described above.
  • Way 1 when a UE receives the configuration for a CHO with candidate SCGs procedure (i.e., CHO configuration referring to or including CPC or CPA configuration, or, a set of configurations for at least one candidate PCell, a set of configurations for at least one candidate PSCell a set of CHO execution conditions for the at least one candidate PCell and a set of CPAC execution conditions for the at least one candidate PSCell) , CHO evaluation and CPAC (i.e.
  • CPC or CPA evaluation may be concurrent, e.g., the UE starts evaluation of CHO execution condition (s) for candidate (target) PCells and CPAC execution condition (s) for candidate (target) PSCells at the same time (e.g., when receiving the configuration for a CHO with candidate SCGs procedure, or when receiving a set of configurations for at least one candidate PCell, a set of configurations for at least one candidate PSCell a set of CHO execution conditions for the at least one candidate PCell and a set of CPAC execution conditions for the at least one candidate PSCell) .
  • Embodiment 1 aims to solve issues of when to stop CPAC evaluation in case that CHO execution condition is fulfilled firstly, when to stop CHO evaluation in case that CPAC execution condition is fulfilled firstly, and how to handle failure cases happen in a CHO with candidate SCGs procedure.
  • Embodiment 1 may include following sub-embodiments (i.e., Embodiment 1-1 and Embodiment 1-2) in different cases (i.e., “Case a” to “Case j” ) .
  • Embodiment 1-1 aims to solve issues of when to stop CHO evaluation in case that CPAC execution condition (s) of any candidate PSCell is fulfilled first and how to handle failure cases.
  • Embodiment 1-1 may include following sub-embodiments in different scenarios, i.e., Embodiment 1-1-1, Embodiment 1-1-2, Embodiment 1-1-3, and Embodiment 1-1-4.
  • Embodiment 1-1-1 is a diagrammatic representation of Embodiment 1-1-1
  • Embodiment 1-1-1 in case that the CPAC execution condition (s) of a candidate (target) PSCell is fulfilled firstly, the UE continues CHO execution condition evaluation of one or more candidate PCell (s) which are associated with the CPAC execution condition fulfilled candidate (target) PSCell, until source SCG failure happens.
  • Case a a source SCG failure happens, but CHO execution condition of none candidate PCell (i.e. which are associated with the CPAC execution condition fulfilled candidate (target) PSCell) is fulfilled, and Embodiment 1-1-1 may be performed.
  • the UE keeps the configuration for a CHO with candidate SCGs procedure, the UE sends SCG failure related information to a source MN (e.g., including an indication that CPAC execution condition (s) configured for a CHO with candidate SCGs procedure is fulfilled, and an indication that CHO execution condition (s) configured for a CHO with candidate SCGs procedure is not fulfilled) .
  • a source MN e.g., including an indication that CPAC execution condition (s) configured for a CHO with candidate SCGs procedure is fulfilled, and an indication that CHO execution condition (s) configured for a CHO with candidate SCGs procedure is not fulfilled
  • the source MN may reconfigure for the UE (e.g., reconfigure a new CHO with candidate SCGs procedure, or reconfigure CHO, handover (HO) , CPA, CPC, PSCell Addition (PA) , or Primary Cell (PC) ) .
  • Case a may include following two sub-cases.
  • Case a-1 new configuration (s) is received by the UE.
  • previous configuration for a CHO with candidate SCGs procedure is released by the UE, the UE acts based on the latest configuration.
  • Case a-2 a source MCG failure happens (e.g., before new configuration (s) is received by the UE) .
  • the UE may perform “failure recovery for a CHO with candidate SCGs procedure” as described above, optionally, the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the source MCG failure occurs.
  • network e.g. source MN
  • Embodiment 1-1-2 in case that the CPAC execution condition (s) of a candidate (target) PSCell is fulfilled first, the UE continues CHO execution condition evaluation of one or more candidate PCell (s) which are associated with the CPAC execution condition fulfilled candidate (target) PSCell, until source MCG failure happens.
  • Case b Source MCG failure happens but CHO execution condition of none candidate PCell (i.e. which are associated with the CPAC execution condition fulfilled candidate (target) PSCell) is fulfilled, and Embodiment 1-1-2 may be performed.
  • the UE may perform “failure recovery for a CHO with candidate SCGs procedure” as described above.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the source MCG failure occurs but CHO execution condition of none candidate PCell is fulfilled.
  • network e.g. source MN
  • Case b another solution is that the UE sends MCG failure related information to a source SN (including an indication that CPAC execution condition configured for a CHO with candidate SCGs procedure is fulfilled, and an indication that CHO execution condition configured for a CHO with candidate SCGs procedure is not fulfilled) .
  • the source SN may transfer the MCG failure related information to source MN.
  • the source MN may reconfigure for the UE (e.g., reconfigure a new CHO with candidate SCGs procedure, or reconfigure CHO or HO or CPA or CPC or PA or PC) via the source SN.
  • Case b may include following two sub-cases.
  • Case b-1 new configuration (s) is received by the UE.
  • previous configuration for a CHO with candidate SCGs procedure is released by the UE, the UE acts based on the latest configuration.
  • Case b-2 a source SCG failure happens (e.g., before new configuration (s) is received by the UE) .
  • the UE may perform “failure recovery for a CHO with candidate SCGs procedure” as described above.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the source SCG failure occurs.
  • network e.g. source MN
  • Embodiment 1-1-3 in case that the CPAC execution condition (s) of a candidate (target) PSCell is fulfilled first, the UE continues CHO execution condition evaluation of one or more candidate PCell (s) which are for the associated with the CPAC execution condition fulfilled candidate (target) PSCell until a configured time duration is reached.
  • Source MN or candidate target MN may configure the time duration for evaluating CHO execution condition after CPAC execution condition is fulfilled.
  • Case c the time duration is reached but CHO execution condition of none candidate PCell (i.e. which is associated with the CPAC execution condition fulfilled candidate (target) PSCell) is fulfilled, and Embodiment 1-1-3 may be performed.
  • the UE may perform “failure recovery for a CHO with candidate SCGs procedure” as described above.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the time duration is reached but CHO execution condition is not fulfilled.
  • network e.g. source MN
  • CHO execution condition (s) of at least a candidate (target) PCell associated with the CPAC-execution-condition-fulfilled candidate (target) PSCell may be fulfilled. If so, the UE may perform a RA procedure to access the CHO-execution-condition-fulfilled (candidate) target PCell and the CPAC-execution-condition-fulfilled (candidate) target PSCell, and Case d may occur in Embodiment 1-1-1 or Embodiment 1-1-2 or Embodiment 1-1-3.
  • Case d a source SCG failure happens during CHO execution (e.g., during a RA procedure towards the target PCell, or when the UE handover or access to the target PCell) .
  • a UE may firstly perform a RA procedure to a target PCell, and then perform a RA procedure to a target PSCell. Simultaneous RA procedures are not supported.
  • the UE may stop CHO execution, and then perform “failure recovery for a CHO with candidate SCGs procedure” as described above.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when source SCG failure happens during CHO execution.
  • network e.g. source MN
  • the UE may indicate the target MN that source SCG failure happens after CPAC execution condition is fulfilled and before CPAC is executed, and/or source SCG failure happens during CHO execution.
  • Target MN may decide later action, e.g., whether or how to reconfigure CPA/CPC/PA/PC for the UE.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to select a candidate PSCell which is associated with the target PCell, or an indication from network (e.g. source MN) that indicates the UE to select the best cell/beam quality candidate PSCell which is associated with the target PCell, when the target PCell is selected or when handover/access to the target PCell is successful or when CHO execution succeeds.
  • network e.g. source MN
  • the UE may evaluate the CPAC execution condition (s) for at least one candidate (target) PSCell (s) which are associated with the target PCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform CPAC execution condition evaluation of any candidate PSCell which is associated with the target PCell, when the target PCell is selected or when handover/access to the target PCell is successful or when CHO execution succeeds:
  • the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • the UE may decide any one within the more than one candidate (target) PSCells as the target PSCell, or the best one (e.g. best cell/beam quality) within the more than one candidate (target) PSCells as the target PSCell, and then, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC. For example, the target MN may decide a subsequent action related to reconfiguring the CPAC procedure.
  • the UE may perform “failure recovery for a CHO with candidate SCGs procedure” as described above.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when CHO execution fails.
  • network e.g. source MN
  • Embodiment 1-2 In case that CHO execution condition (s) of any candidate PCell is fulfilled firstly, Embodiment 1-2 to solve issues of when to stop CPAC evaluation in case that CHO execution condition (s) of any candidate PCell is fulfilled first and how to handle failure cases.
  • Embodiment 1-2 may include following sub-embodiments in different scenarios, i.e., Embodiment 1-2-1, Embodiment 1-2-2, Embodiment 1-2-3, Embodiment 1-2-4, and Embodiment 1-2-5.
  • Embodiment 1-2-1 in case that the CHO execution condition (s) of a candidate (target) PCell is fulfilled firstly, when CHO execution condition (s) of a candidate (target) PCell is fulfilled, the UE continues CPAC execution condition evaluation (s) of one or more candidate PSCell (s) which are associated with the CHO execution condition fulfilled candidate (target) PCell, until a source SCG failure happens.
  • Case e a source SCG failure happens but CPAC execution condition (s) of none candidate PSCell (i.e. which is associated with the CHO execution condition fulfilled candidate (target) PCell) is fulfilled, and Embodiment 1-2-1 may be performed.
  • the UE performs CHO execution to the target PCell (e.g., a handover to the target PCell, or a RA procedure towards the target PCell, or access to the target PCell) .
  • the UE further checks whether the target PCell is available, e.g., whether CHO execution condition of the target PCell which is previously fulfilled is still fulfilled when source SCG failure happens, and if fulfilled, the UE performs CHO execution to the target PCell. Or, the UE further checks whether leaving condition of the target PCell is not met when source SCG failure happens, and if not met, the UE performs CHO execution to the target PCell. Case e may include following two sub-cases.
  • Case e-1 a CHO execution failure happens (e.g., a handover to the target PCell fails, or a RA procedure towards the target PCell fails, or access to the target PCell fails) .
  • the UE may perform failure recovery for a CHO with candidate SCGs procedure.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the CHO execution failure occurs.
  • network e.g. source MN
  • Case e-2 CHO execution succeeds (e.g., the UE successfully performs a RA procedure towards the target PCell or the target MN, or, handover or access to the target PCell or the target MN succeeds) :
  • the UE may indicate the target MN that CPAC execution condition of none candidate PSCell (i.e. which is associated with the CHO execution condition fulfilled candidate (target) PCell) is fulfilled until source SCG failure.
  • Target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC for the UE.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to select a candidate PSCell which is associated with the target PCell, or an indication from network (e.g. source MN) that indicates the UE to select the best cell/beam quality candidate PSCell which is associated with the target PCell, when CHO execution succeeds or when handover/access/RA procedure to the target PCell is successful.
  • network e.g. source MN
  • the UE may evaluate the CPAC execution condition (s) for at least one candidate (target) PSCell (s) which is associated with the target PCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform CPAC execution condition evaluation of any candidate PSCell which is associated with the target PCell, when CHO execution succeeds or when handover/access/RA procedure to the target PCell is successful:
  • network e.g. source MN
  • the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • the UE may decide any one within the more than one candidate (target) PSCells as the target PSCell, or the best one (e.g. best cell/beam quality) within the more than one candidate (target) PSCells as the target PSCell, and then, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC.
  • Embodiment 1-2-2 in case that the CHO execution condition (s) of a candidate (target) PCell is fulfilled first, when CHO execution condition (s) of a candidate (target) PCell is fulfilled, the UE continues CPAC execution condition evaluation of one or more candidate PSCell (s) which are associated with the CHO execution condition fulfilled candidate (target) PCell, until source MCG failure happens.
  • one solution is that the UE may perform failure recovery for a CHO with candidate SCGs procedure.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when source MCG failure happens and/or CPAC execution condition of none candidate PSCell is fulfilled.
  • network e.g. source MN
  • the UE performs CHO execution to the target PCell (e.g., a handover to the target PCell or a RA procedure towards the target PCell or access to the target PCell) .
  • the UE may further check whether the target PCell is available, e.g., whether CHO execution condition of the target PCell which is previously fulfilled is still fulfilled when source MCG failure happens, and if fulfilled, the UE performs CHO execution to the target PCell.
  • the UE may further check whether leaving condition of the target PCell is not met when source MCG failure happens, and if not met, the UE performs CHO execution to the target PCell.
  • the target PCell e.g., a handover to the target PCell or a RA procedure towards the target PCell or access to the target PCell
  • the UE may further check whether the target PCell is available, e.g., whether CHO execution condition of the target PCell which is previously fulfilled is still fulfilled when source MCG failure happens, and if fulfilled, the UE perform
  • the UE may indicate the target MN that source MCG failure happens and/or CPAC execution condition of none candidate PSCell (i.e. which is associated with the CHO execution condition fulfilled candidate (target) PCell) is fulfilled.
  • Target MN may decide later action, e.g., whether or how to reconfigure CPA/CPC/PA/PC for the UE.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to select a candidate PSCell which is associated with the target PCell, or an indication from network (e.g. source MN) that indicates the UE to select the best cell/beam quality candidate PSCell which is associated with the target PCell, when CHO execution succeeds or when handover/access/RA procedure to the target PCell is successful.
  • network e.g. source MN
  • the UE may evaluate the CPAC execution condition (s) for one or more candidate (target) PSCell (s) which are associated with the target PCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform CPAC execution condition evaluation of any candidate PSCell which is associated with the target PCell, when CHO execution succeeds or when handover/access/RA procedure to the target PCell is successful,
  • network e.g. source MN
  • CPAC execution condition (s) of one candidate (target) PSCell which is associated with the target PCell If CPAC execution condition (s) of one candidate (target) PSCell which is associated with the target PCell is fulfilled, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) . If CPAC execution condition (s) of more than one candidate (target) PSCells which are associated with the target PCell is fulfilled, the UE may decide any one within the more than one candidate (target) PSCells as the target PSCell, or the best one (e.g. best cell/beam quality) within the more than one candidate (target) PSCells as the target PSCell, and then, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • the target PSCell e.g. perform a RACH procedure towards the target PSCell, or access
  • target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC.
  • the UE may perform “failure recovery for a CHO with candidate SCGs procedure” as described above.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when CHO execution fails.
  • network e.g. source MN
  • the UE performs CHO execution to the target PCell (e.g., a handover to the target PCell, or a RA procedure towards the target PCell, or access to the target PCell) upon the target PCell’s CHO execution condition (s) is fulfilled, meanwhile, the UE continues CPAC execution condition evaluation of candidate PSCell which are associated with the CHO execution condition fulfilled target PCell, until CHO execution failure or source SCG failure happens.
  • the target PCell e.g., a handover to the target PCell, or a RA procedure towards the target PCell, or access to the target PCell
  • Case g CHO execution failure happens (e.g., a handover to the target PCell fails, or a RA procedure towards the target PCell fails, or access to the target PCell) , but CPAC execution condition of any candidate PSCell (i.e. which is associated with the CHO execution condition fulfilled candidate (target) PCell) is not fulfilled, and Embodiment 1-2-3 may be performed.
  • the UE may perform “failure recovery for a CHO with candidate SCGs procedure” as described above.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the CHO execution failure occurs.
  • network e.g. source MN
  • one solution is that the UE may indicate the target MN that source SCG failure happens after successful CHO execution and/or CPAC execution condition (s) is not fulfilled.
  • Target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC for the UE.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to select a candidate PSCell which is associated with the target PCell, or an indication from network (e.g. source MN) that indicates the UE to select the best cell/beam quality candidate PSCell which is associated with the target PCell, when source SCG failure happens after successful CHO execution but CPAC execution condition is not fulfilled.
  • network e.g. source MN
  • the UE may evaluate the CPAC execution condition (s) for at least one candidate (target) PSCell (s) which is associated with the target PCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform CPAC execution condition evaluation of any candidate PSCell which is associated with the target PCell, when source SCG failure happens after successful CHO execution but CPAC execution condition is not fulfilled:
  • the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • the UE may decide any one within the more than one candidate (target) PSCells as the target PSCell, or the best one (e.g. best cell/beam quality) within the more than one candidate (target) PSCells as the target PSCell, and then, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC.
  • Embodiment 1-2-4 in case that the CHO execution condition (s) of a candidate (target) PCell is fulfilled first, the UE continues CPAC execution condition evaluation of one or more candidate PSCell (s) which are associated with the CHO execution condition fulfilled candidate (target) PCell until a configured time duration is reached.
  • Source MN or candidate target MN or candidate target SN may configure the time duration for evaluating CPAC execution condition after CHO execution condition (s) is fulfilled.
  • the UE performs CHO execution to the target PCell (e.g., a handover to the target PCell, or a RA procedure towards the target PCell, or access to the target PCell) .
  • the UE may further check whether a target PCell is available, e.g., whether CHO execution condition of the target PCell which is previously fulfilled is still fulfilled when the configured time duration is reached, and if fulfilled, the UE performs CHO execution to the target PCell.
  • the UE may further check whether leaving condition of the target PCell is not met when the configured time duration is reached, and if not met, the UE performs CHO execution to the target PCell.
  • Case i may include following two sub-cases.
  • Case i-1 CHO execution failure happens (e.g., a handover to the target PCell fails, or a RA procedure towards the target PCell fails, or access to the target PCell fails) .
  • the UE may perform failure recovery for a CHO with candidate SCGs procedure.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the CHO execution failure occurs.
  • network e.g. source MN
  • Case i-2 CHO execution succeeds (e.g., the UE successfully performs a RA procedure towards the target PCell or the target MN, or, handover or access to the target PCell or the target MN succeeds) :
  • the UE may indicate the target MN that CPAC execution condition of none candidate PSCell (i.e. which is associated with the CHO execution condition fulfilled candidate (target) PCell) is fulfilled.
  • Target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC for the UE.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to select a candidate PSCell which is associated with the target PCell, or an indication from network (e.g. source MN) that indicates the UE to select the best cell/beam quality candidate PSCell which is associated with the target PCell, when CHO execution succeeds or when handover/access/RA procedure to the target PCell is successful.
  • network e.g. source MN
  • the UE may evaluate the CPAC execution condition (s) for at least one candidate (target) PSCell (s) which is associated with the target PCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform CPAC execution condition evaluation of any candidate PSCell which is associated with the target PCell, when CHO execution succeeds or when handover/access/RA procedure to the target PCell is successful:
  • network e.g. source MN
  • the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) . If CPAC execution condition (s) of more than one candidate (target) PSCells which are associated with the target PCell is fulfilled, the UE may decide any one within the more than one candidate (target) PSCells as the target PSCell, or the best one (e.g. best cell/beam quality) within the more than one candidate (target) PSCells as the target PSCell. Then, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • the target PSCell e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell
  • target MN may decide later action, e.g., whether or how to reconfigure CPA/CPC/PA/PC.
  • Embodiment 1-2-1 or Embodiment 1-2-2 or Embodiment 1-2-3 or Embodiment 1-2-4 CPAC execution condition (s) of at least a candidate (target) PSCell associated with the CHO-execution-condition-fulfilled candidate (target) PCell may be fulfilled. If so, the UE may perform a RA procedure to access the CHO-execution-condition-fulfilled (candidate) target PCell and the CPAC- execution-condition-fulfilled (candidate) target PSCell, Case j may occur in Embodiment 1-2-1 or 1-2-2 or 1-2-3 or 1-2-4.
  • Case j source SCG failure happens during CHO execution (e.g., during a RA procedure towards the target PCell, or when the UE handover or access to the target PCell) .
  • the UE firstly performs a RA procedure to a target PCell, and then perform a RA procedure to a target PSCell.
  • a simultaneous RA procedure is not supported.
  • Embodiment 2 provides a solution for Way 2 as described above.
  • Way 2 when the UE receives the configuration for a CHO with candidate SCGs procedure (i.e., CHO configuration referring to or including CPC or CPA configuration, or, a set of configurations for at least one candidate PCell, a set of configurations for at least one candidate PSCell a set of CHO execution conditions for the at least one candidate PCell and a set of CPAC execution conditions for the at least one candidate PSCell) , CHO evaluation and CPAC (i.e. CPC or CPA) evaluation may be sequential. For example, the UE firstly starts evaluation of execution condition (s) for candidate (target) PCells.
  • the UE evaluates CPAC execution condition (s) of at least one candidate (target) PSCell (s) which are associated with the CHO execution condition fulfilled candidate (target) PCell.
  • CPAC execution condition (s) of at least one candidate (target) PSCell (s) which are associated with the CHO execution condition fulfilled candidate (target) PCell.
  • (1) Way 2-1 when CHO execution condition (s) of a candidate (target) PCell is fulfilled, the UE evaluates CPAC execution condition (s) of one or more candidate (target) PSCell (s) that associated with the CHO execution condition fulfilled candidate (target) PCell. If CPAC execution condition (s) of a candidate (target) PSCell (e.g. which is within the one or more candidate (target) PSCell (s) that associated with the CHO execution condition fulfilled candidate (target) PCell) is fulfilled as well, the UE may perform a RA procedure to access the CHO-execution-condition-fulfilled (candidate) target PCell and the CPAC-execution-condition-fulfilled (candidate) target PSCell
  • (2) Way 2-2 when CHO execution condition (s) of a candidate (target) PCell is fulfilled, the UE performs CHO execution towards this (candidate) target PCell. Meanwhile, when performing CHO execution, the UE starts evaluating CPAC execution condition of one or more candidate (target) PSCell (s) that associated with the CHO execution condition fulfilled candidate (target) PCell.
  • Embodiment 2 aims to solve an issue of how to handle failure cases happen in a CHO with candidate SCGs procedure.
  • Embodiment 2 may include following sub-embodiments in different scenarios, i.e., Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3.
  • Case k the UE detects an RLF in a source SCG before CHO execution condition (s) of any candidate PCell is fulfilled or before CHO execution is performed or before CPAC execution condition (s) of any candidate PSCell is fulfilled” may happen.
  • Case m the UE detects RLF in source SCG before CHO execution condition is fulfilled or before CHO execution is performed” may happen.
  • the UE may stop CHO evaluation or CPAC evaluation, and may perform failure recovery for a CHO with candidate SCGs procedure.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the source SCG failure occurs.
  • network e.g. source MN
  • Another solution is that the UE keeps the configuration for a CHO with candidate SCGs procedure, the UE sends SCG failure related information to a source MN (including an indication that CPAC execution condition (s) configured for a CHO with candidate SCGs procedure is not fulfilled, and an indication that CHO execution condition (s) configured for a CHO with candidate SCGs procedure is not fulfilled) .
  • the source MN may reconfigure for the UE (e.g., reconfigure a new CHO with candidate SCGs procedure, or reconfigure CHO or HO or CPA or CPC or PA or PC) .
  • reconfigure for the UE e.g., reconfigure a new CHO with candidate SCGs procedure, or reconfigure CHO or HO or CPA or CPC or PA or PC.
  • the UE may perform “failure recovery for a CHO with candidate SCGs procedure” as described above.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the source MCG failure occurs.
  • network e.g. source MN
  • Case n “the UE detects RLF in source SCG during CHO execution and before CPAC execution condition (s) of any candidate PSCell is fulfilled” may happen.
  • failure case e.g., source SCG failure during CHO execution and before CPAC execution condition (s) of any candidate PSCell is fulfilled
  • the UE may stop CHO execution, and may perform failure recovery for a CHO with candidate SCGs procedure.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when the source SCG failure occurs.
  • network e.g. source MN
  • CHO execution succeeds (e.g., the UE successfully performs a RA procedure towards the target PCell or the target MN, or the UE successfully access or handover to the target PCell or the target MN) ,
  • the UE may indicate the target MN that source SCG failure happens during CHO execution and/or CPAC execution condition (s) is not fulfilled.
  • Target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC for the UE.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to select a candidate PSCell which is associated with the target PCell, or an indication from network (e.g. source MN) that indicates the UE to select the best cell/beam quality candidate PSCell which is associated with the target PCell, when CHO execution succeeds or handover/access/RA procedure to the target PCell is successful.
  • network e.g. source MN
  • the UE may evaluate the CPAC execution condition (s) for any candidate (target) PSCell (s) which is associated with the target PCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform CPAC execution condition evaluation of any candidate PSCell which is associated with the target PCell, when CHO execution succeeds or handover/access/RA procedure to the target PCell is successful :
  • the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • the UE may decide any one within the more than one candidate (target) PSCells as the target PSCell, or the best one (e.g. best cell/beam quality) within the more than one candidate (target) PSCells as the target PSCell. Then, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) l.
  • the UE indicates source SCG failure to the target MN, and/or, the UE indicates that CPAC execution condition (s) is not met to target MN (e.g. indicates that CPAC execution condition (s) of one or more candidate (target) PSCells which are associated with the target PCell is not fulfilled)
  • target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC.
  • the UE may perform “failure recovery for a CHO with candidate SCGs procedure” as described above.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform the “failure recovery for a CHO with candidate SCGs procedure” , when CHO execution fails.
  • network e.g. source MN
  • Case p “the UE detects RLF in source SCG after successful CHO execution and before CPAC execution condition (s) of any candidate PSCell is fulfilled” may happen.
  • source SCG failure after successful CHO execution and before CPAC execution condition (s) of any candidate PSCell is fulfilled source SCG failure after successful CHO execution and before CPAC execution condition (s) of any candidate PSCell is fulfilled
  • the UE may indicate the target MN that source SCG failure happens after successful CHO execution and/or CPAC execution condition (s) of any candidate PSCell is not fulfilled.
  • the target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC for the UE.
  • the UE may select any candidate (target) PSCell or the best candidate (target) PSCell which is associated with the target PCell to add it as target PSCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to select a candidate PSCell which is associated with the target PCell, or an indication from network (e.g. source MN) that indicates the UE to select the best cell/beam quality candidate PSCell which is associated with the target PCell, when CHO execution or handover/access/RA procedure to the target PCell is successful, or when source SCG fails after successful CHO execution and before CPAC execution condition (s) of any candidate PSCell is fulfilled.
  • network e.g. source MN
  • the UE may evaluate the CPAC execution condition (s) for any candidate (target) PSCell (s) which is associated with the target PCell.
  • the UE may receive an indication from network (e.g. source MN) that indicates the UE to perform CPAC execution condition evaluation of any candidate PSCell which is associated with the target PCell, when CHO execution or handover/access/RA procedure to the target PCell is successful, or when source SCG fails after successful CHO execution and before CPAC execution condition (s) of any candidate PSCell is fulfilled:
  • network e.g. source MN
  • CPAC execution condition (s) of one candidate (target) PSCell which is associated with the target PCell If CPAC execution condition (s) of one candidate (target) PSCell which is associated with the target PCell is fulfilled, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) . If CPAC execution condition (s) of more than one candidate (target) PSCells which are associated with the target PCell is fulfilled, the UE may decide any one within the more than one candidate (target) PSCells as the target PSCell, or the best one (e.g. best cell/beam quality) within the more than one candidate (target) PSCells as the target PSCell, and then, the UE may add the target PSCell (e.g. perform a RACH procedure towards the target PSCell, or access to the target PSCell) .
  • the target PSCell e.g. perform a RACH procedure towards the target PSCell, or access
  • the UE indicates source SCG failure happens after successful CHO execution to target MN, and/or, the UE indicates that CPAC execution condition (s) is not met to target MN (e.g. indicates that CPAC execution condition (s) of one or more candidate (target) PSCells which are associated with the target PCell is not fulfilled)
  • target MN may decide later action, e.g., whether or how to reconfigure CPA or CPC or PA or PC.
  • FIG. 4 illustrates a block diagram of an exemplary apparatus 400 in accordance with some embodiments of the present disclosure.
  • the apparatus 400 may include at least one processor 406 and at least one transceiver 402 coupled to the processor 406.
  • the transceiver 402 may be divided into two devices, such as a receiving circuitry and a transmitting circuitry.
  • the apparatus 400 may further include an input device, a memory, and/or other components.
  • the apparatus 400 may be a UE, a target MN, a source MN, a target SN, or a source SN.
  • the transceiver 402 and the processor 406 may interact with each other so as to perform the operations with respect to the UE, the target MN, the source MN, the target SN, or the source SN described above, for example, in any of FIGS. 1-3.
  • the apparatus 400 may further include at least one non-transitory computer-readable medium.
  • the non-transitory computer-readable medium may have stored thereon computer-executable instructions to cause the processor 406 to implement the method with respect to the UEs as described above.
  • the computer-executable instructions when executed, cause the processor 406 interacting with transceiver 402 to perform the operations with respect to the UE, the target MN, the source MN, the target SN, or the source SN described in FIGS. 1-3.
  • a software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
  • the operations or steps of a method may reside as one or any combination or set of codes and/or instructions on a non-transitory computer-readable medium, which may be incorporated into a computer program product.
  • the terms “includes, “ “including, “ or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
  • An element proceeded by “a, “ “an, “ or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element.
  • the term “another” is defined as at least a second or more.
  • the term “having” and the like, as used herein, are defined as "including.
  • Expressions such as “Aand/or B” or “at least one of A and B” may include any and all combinations of words enumerated along with the expression.
  • the expression “A and/or B” or “at least one of A and B” may include A, B, or both A and B.
  • the wording "the first, " “the second” or the like is only used to clearly illustrate the embodiments of the present application, but is not used to limit the substance of the present application.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Un équipement utilisateur (UE) comprend un émetteur-récepteur et un processeur couplé à l'émetteur-récepteur, et le processeur est configuré pour : recevoir, par l'intermédiaire de l'émetteur-récepteur à partir d'un nœud maître (NM) source, au moins l'un parmi : un ensemble de configurations pour au moins une cellule primaire candidate (PCell), un ensemble de configurations pour au moins une PSCell candidate, un ensemble de conditions d'exécution de transfert conditionnel (CHO) pour l'au moins une PCell candidate, ou un ensemble de conditions d'exécution d'ajout ou de changement (CPAC) de cellule de groupe de cellules secondaires primaires (PSCell) conditionnelles pour la ou les PSCell candidates ; et en réponse à au moins une occurrence d'une défaillance de groupe de cellules secondaires (SCG) source, l'occurrence d'une défaillance de groupe de cellules maîtresses source (MCG), la non-exécution de l'ensemble de conditions d'exécution CHO, l'exécution de l'ensemble de conditions d'exécution CPAC, ou l'occurrence d'une défaillance pendant une exécution CHO, réaliser l'une parmi : l'initiation d'une procédure de reprise après défaillance ; l'initiation d'une exécution CHO ; et la poursuite de l'exécution CHO.
PCT/CN2022/122704 2022-09-29 2022-09-29 Procédés et appareils d'une procédure cho avec des scgs candidats WO2024065419A1 (fr)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021172964A1 (fr) * 2020-02-27 2021-09-02 Lg Electronics Inc. Procédé et appareil de récupération après une panne dans un système de communication sans fil
WO2022021272A1 (fr) * 2020-07-31 2022-02-03 Zte Corporation Procédé d'ajout et de changement de cellules primaires conditionnelles dans un groupe de cellules secondaires
CN114079962A (zh) * 2020-08-12 2022-02-22 财团法人工业技术研究院 次要小区群组失效处理方法与使用所述方法的用户设备
CN114503667A (zh) * 2019-10-03 2022-05-13 高通股份有限公司 用于添加和/或改变辅节点（sn）的有条件过程
CN114930908A (zh) * 2020-01-10 2022-08-19 联想(北京)有限公司 条件移交中的故障处理的方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114503667A (zh) * 2019-10-03 2022-05-13 高通股份有限公司 用于添加和/或改变辅节点（sn）的有条件过程
CN114930908A (zh) * 2020-01-10 2022-08-19 联想(北京)有限公司 条件移交中的故障处理的方法
WO2021172964A1 (fr) * 2020-02-27 2021-09-02 Lg Electronics Inc. Procédé et appareil de récupération après une panne dans un système de communication sans fil
WO2022021272A1 (fr) * 2020-07-31 2022-02-03 Zte Corporation Procédé d'ajout et de changement de cellules primaires conditionnelles dans un groupe de cellules secondaires
CN114079962A (zh) * 2020-08-12 2022-02-22 财团法人工业技术研究院 次要小区群组失效处理方法与使用所述方法的用户设备

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
LG ELECTRONICS INC.: "SCG Failure Handling with Conditional PSCell", 3GPP TSG RAN WG2 MEETING #108, R2-1916207, 8 November 2019 (2019-11-08), XP051817751 *

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