Method and apparatus for managing scpac configuration in a wireless communication system

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Embodiments disclose methods and systems (wireless network) for managing a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in a user equipment (UE) (102). The method includes receiving a SCPAC reference configuration and at least one SCPAC candidate configuration from a network entity (110).

Description

METHOD AND APPARATUS FOR MANAGING SCPAC CONFIGURATION IN A WIRELESS COMMUNICATION SYSTEM

[0001] Embodiments disclosed herein relate to wireless communication networks, and more particularly to methods and systems (or wireless network) for managing a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in a user equipment (UE).

[0002] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in “Sub 6GHz” bands such as 3.5GHz, but also in “Above 6GHz” bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz (THz) bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0003] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0004] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0005] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0006] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

[0008] This disclosure relates to wireless communication networks, and more particularly to a terminal and a communication method thereof in a wireless communication system.

[0009] The embodiment discloses a method for managing a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in a user equipment (UE). The method includes receiving, by the UE, a SCPAC reference configuration and at least one SCPAC candidate configuration from a network entity. The method includes generating and storing, by the UE, at least one Radio Resource Control (RRC) Re-configuration message by applying the at least one SCPAC candidate configuration on the SCPAC reference configuration. The method includes determining by the UE, at least one of: that the SCPAC reference configuration and at least one SCPAC candidate configuration is modified by the network entity. Further, the method includes regenerating, by the UE, the stored at least one RRC Re-configuration message for at least one SCPAC candidate configuration based on the determination, wherein the at least one candidate configuration is not complete SCPAC candidate configuration.

[0010] Aspects of the disclosure are to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide a terminal and a communication method thereof in a wireless communication system.

[0011] Embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the following illustratory drawings. Embodiments herein are illustrated by way of examples in the accompanying drawings, and in which:

[0012] FIG. 1A is an example block diagram depicting the communication of a User Equipment (UE) and a network entity for managing a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in a wireless communication network, according to embodiments as disclosed herein;

[0013] FIG. 1B shows various hardware components of the UE, according to embodiments as disclosed herein;

[0014] FIG. 1C shows various hardware components of a network entity, according to embodiments as disclosed herein;

[0015] FIG. 2 is an example diagram depicting the method for handling the scpac-ReferenceConfiguration, according to embodiments as disclosed herein;

[0016] FIG. 3 is an example diagram depicting the method for releasing the scpac-ReferenceConfiguration, according to embodiments as disclosed herein;

[0017] FIG. 4 is an example diagram depicting the method for executing SCPACs, according to embodiments as disclosed herein;

[0018] FIG. 5 is an example diagram depicting the method for managing a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in the user equipment (UE), according to embodiments as disclosed herein;

[0019] FIG. 6 is an example diagram depicting the method for executing a Subsequent Conditional Primary Secondary CellGroup (SCG) Cell Addition or Change (SCPAC) in the user equipment (UE), according to embodiments as disclosed herein;

[0020] FIG. 7 is an example diagram depicting the method for managing SCPAC configuration in the UE using a network entity, according to embodiments as disclosed herein;

[0021] FIG. 8 is an example diagram depicting the method for releasing conditional execution conditions for SCPAC, according to embodiments as disclosed herein;

[0022] FIG. 9 is an example diagram depicting the method for managing SCGFailureInformation and SCPAC, according to embodiments as disclosed herein;

[0023] FIG. 10 is an example diagram depicting the method for managing the LTM Cell Switch / Subsequent CPAC execution, according to embodiments as disclosed herein;

[0024] FIG. 11 illustrates various hardware components of a network entity, according to the embodiments as disclosed herein;

[0025] FIG. 12 illustrates various hardware components of a UE, according to the embodiments as disclosed herein; and

[0026] FIG. 13 illustrates various hardware components of a base station according to the embodiments as disclosed herein.

[0027] The embodiment discloses a method for managing a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in a user equipment (UE). The method includes receiving, by the UE, a SCPAC reference configuration and at least one SCPAC candidate configuration from a network entity. The method includes generating and storing, by the UE, at least one Radio Resource Control (RRC) Re-configuration message by applying the at least one SCPAC candidate configuration on the SCPAC reference configuration. The method includes determining by the UE, at least one of: that the SCPAC reference configuration and at least one SCPAC candidate configuration is modified by the network entity. Further, the method includes regenerating, by the UE, the stored at least one RRC Re-configuration message for at least one SCPAC candidate configuration based on the determination, wherein the at least one candidate configuration is not complete SCPAC candidate configuration.

[0028] The embodiments disclose a method for managing a Subsequent Conditional Primary Secondary CellGroup (SCG) Cell Addition or Change (SCPAC) in a user equipment (UE). The method includes executing the SCPAC by using relevant configurations. Further, the method includes releasing, by the UE, the current dedicated configuration, wherein the UE retains the configuration for at least one of: a Successful PSCell Change or Addition Information Report (SPR) configuration and a Secondary Node (SN) initiated PSCellChange flag in the release, when at least one of the SPR configuration and SN initiated PSCellChange flag is present in a current dedicated configuration provided by a network entity.

[0029] The embodiments disclose a method for managing a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in a user equipment (UE). The method includes transmitting, by a network entity, a Radio Resource Control (RRC) Re-configuration message to release a reference configuration (scpac-ReferenceConfiguration) for a subsequent CPAC configuration. The method includes releasing, by the network entity, at least one conditional RRC Re-configuration message of the SCPAC configuration, wherein the at least one conditional RRC Re-configuration message is not complete SCPAC configuration.

[0030] The embodiments disclose a User Equipment (UE), comprising: a processor; a memory; and a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) managing controller, coupled with the processor and the memory. The SCPAC managing controller receives a SCPAC reference configuration and at least one SCPAC candidate configuration from a network entity. The SCPAC managing controller generates and stores at least one Radio Resource Control (RRC) Re-configuration message by applying the at least one SCPAC candidate configuration on the SCPAC reference configuration. SCPAC managing controller determines at least one of: that the SCPAC reference configuration and at least one SCPAC candidate configuration is modified by the network entity. The SCPAC managing controller regenerates the stored at least one RRC Re-configuration message for at least one SCPAC candidate configuration based on the determination, wherein the at least one candidate configuration is not complete SCPAC candidate configuration.

[0031] The embodiments disclose a User Equipment (UE), comprising: a processor; a memory; and a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) managing controller, coupled with the processor and the memory. The SCPAC managing controller executes the SCPAC by using the relevant configurations. The SCPAC managing controller releases the current dedicated configuration, wherein the UE retains the configuration for at least one of: a Successful PSCell Change or Addition Information Report (SPR) configuration and a Secondary Node (SN) initiated PSCellChange flag in the release, when at least one of the SPR configuration and SN initiated PSCellChange flag is present in a current dedicated configuration provided by a network entity.

[0032] The embodiments disclose a network entity, comprising: a processor (112); and a memory. The network entity transmits a Radio Resource Control (RRC) Re-configuration message to release a reference configuration (scpac-ReferenceConfiguration) for a subsequent CPAC configuration. The network entity releases at least one conditional RRC Re-configuration message of the SCPAC configuration, wherein the at least one conditional RRC Re-configuration message is not complete SCPAC configuration.

[0033] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating at least one embodiment and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the scope thereof, and the embodiments herein include all such modifications.

[0034] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0035] For the purposes of interpreting this specification, the definitions (as defined herein) will apply and whenever appropriate the terms used in singular will also include the plural and vice versa. It is to be understood that the terminology used herein is for the purposes of describing particular embodiments only and is not intended to be limiting. The terms “comprising”, “having” and “including” are to be construed as open-ended terms unless otherwise noted.

[0036] The words / phrases "exemplary", “example”, “illustration”, “in an instance”, “and the like”, “and so on”, “etc.”, “etcetera”, “e.g.,” , “i.e.,” are merely used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein using the words / phrases "exemplary", “example”, “illustration”, “in an instance”, “and the like”, “and so on”, “etc.”, “etcetera”, “e.g.,”, “i.e.,” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0037] Embodiments herein may be described and illustrated in terms of blocks which carry out a described function or functions. These blocks, which may be referred to herein as managers, units, modules, hardware components or the like, are physically implemented by analog and / or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and may optionally be driven by a firmware. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like. The circuits constituting a block may be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block. Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of the disclosure. Likewise, the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of the disclosure.

[0038] It should be noted that elements in the drawings are illustrated for the purposes of this description and ease of understanding and may not have necessarily been drawn to scale. For example, the flowcharts / sequence diagrams illustrate the method in terms of the steps required for understanding of aspects of the embodiments as disclosed herein. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the present embodiments so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Furthermore, in terms of the system, one or more components / modules which comprise the system may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the present embodiments so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0039] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any modifications, equivalents, and substitutes in addition to those which are particularly set out in the accompanying drawings and the corresponding description. Usage of words such as first, second, third etc., to describe components / elements / steps is for the purposes of this description and should not be construed as sequential ordering / placement / occurrence unless specified otherwise.

[0040] Embodiments herein disclose methods and systems for a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in a user equipment (UE).

[0041] In Fifth-Generation new radio (5G NR) network (wireless technologies), devices can move across different cells. Mobility is performed using a procedure called cell reselection in RRC_IDLE mode. Until NR Release 17, mobility was performed using a procedure called handover in RRC_CONNECTED mode. Network-controlled mobility applies to UEs in RRC_CONNECTED mode and requires explicit RRC signaling triggered by a gNB in the NR. Handover in NR is performed by three steps: handover preparation, handover execution, and handover completion. The gNB may configure the UE to report measurements, and based on the reported measurements or its understanding of the network topology, the gNB sends an RRC Reconfiguration message to hand over the UE from the source cell to the target cell. The UE accesses the target cell and responds with an RRC Reconfiguration Complete message.

[0042] In an alternative method introduced in Third-Generation Partnership Project (3GPP) NR Release 16, the gNB may configure the UE with execution conditions for triggering the handover. Once the execution conditions are satisfied, the UE may move to the target cell and send the RRC Reconfiguration Complete message. 3GPP also introduced a new handover method called DAPS handover in Release 16. In existing methods, the UE may handover by sending Layer 3 (RRC) messages, which causes considerable signaling overhead and latency issues.

[0043] The handover and conditional handover (CHO) can be collectively referred to as Layer 3 mobility. In dual connectivity, the UE may perform PSCellChange or Conditional PSCellChange, which is referred to as Layer 3 mobility. Therefore, handover, conditional handover, PSCellChange, and Conditional PSCellChange are examples of Layer 3 mobility. In dual connectivity, PSCellChange or Conditional PSCellChange can be referred to as SCG Layer 3 mobility, while handover and CHO can be referred to as MCG Layer 3 mobility.

[0044] The 5G NR (New Radio) radio access network, referred as Next Generation Radio Access Network (NG-RAN), comprises a number of NR base stations known as gNBs. The gNBs can be connected to each other through the Xn interface and to various core network elements may include, but not limited to AMF (Access and Mobility Management Function) and UPF (User Plane Function). Furthermore, gNBs can be divided into two physical entities: the CU (Centralized Unit) and the DU (Distributed Unit). The CU provides support for the higher layers of the protocol stack such as SDAP (Session Data Application Protocol), PDCP (Packet Data Convergence Protocol), and RRC (Radio Resource Control), while the DU provides support for the lower layers of the protocol stack such as RLC (Radio Link Control), MAC (Medium Access Control), and the Physical layer. Each gNB can have multiple cells serving many UEs (User Equipment).

[0045] Large number of algorithms and configuration parameters are used in NG-RAN. Identifying the most optimal radio parameters is challenging, and relied on manual techniques, such as drive tests, to determine the parameters. However, the manual parameter tuning is a costly operation as it depends on numerous factors, such as the number of users, the number of neighbors, the maximum throughput in the cell, and the average throughput in the cell. Additionally, whenever a neighboring gNB is installed or a new service is introduced, many of the manual operations need to be repeated.

[0046] The 3GPP introduced Self-Organizing Networks (SON) techniques in wireless technologies like NR. SON was first introduced in 3GPP Release 9, in LTE. SON solutions can be divided into three categories: self-configuration, self-optimization, and self-healing. The SON architecture can be centralized, distributed, or hybrid.

[0047] One of the functions of Mobility Robustness Optimization is to detect sub-optimal successful mobility, which could include successful PCell Change, successful PSCell Change, or sub-optimal successful PSCell Addition events. Successful PCell Change is handled using the Successful Handover Report (SHR), while successful PSCell Addition and successful PSCell Change is handled using the Successful PSCell Report (SPR).

[0048]

[0049] The Network configures the UE for reporting SPR using OtherConfig as given below using RRC messages such as RRCReconfiguration in NR.

[0050]

[0051] From above, the sn-InitiatedPSCellChange is provided as a Need M parameter, which means the UE which has received an OtherConfig including sn-InitiatedPSCellChange maintains the value, and if it receives another RRCReconfiguration message without sn-InitiatedPSCellChange, it applies the value received in previous RRCReconfiguration message.

[0052] In the existing method, SPR contents may be as follows: in SuccessPSCell-Report field descriptions, the measResultListNR field refers to the last measurement results according to the initiating node configuration taken in the neighboring NR Cells when a successful PSCell change / addition is executed.

[0053] The pCellId field is used to indicate the PCell to which the UE was connected when the successful PSCell change or addition triggers the SuccessPSCell-Report.

[0054] The sn-InitiatedPSCellChange field indicates whether the PSCell change procedure for which the successful PSCell change report is logged is SN initiated or not.

[0055] The spr-Cause field is used to indicate the cause of the successful PSCell change or addition report.

[0056] The sourcePSCellId field is used to indicate the source PSCell of a PSCell change in which the successful PSCell change triggers the SuccessPSCell-Report.

[0057] The sourcePSCellMeas field refers to the last measurement results taken in the source PSCell of a PSCell change in which the successful PSCell change triggers the SuccessPSCell-Report.

[0058] The targetPSCellId field is used to indicate the target PSCell of a PSCell change / addition in which the successful PSCell change or addition triggers the SuccessPSCell-Report.

[0059] The targetPSCellMeas field refers to the last measurement results taken in the target PSCell of a PSCell change / addition in which the successful PSCell change or addition triggers the SuccessPSCell-Report.

[0060] The timeSinceCPAC-Reconfig field is used to indicate the time elapsed between the initiation of the last conditional reconfiguration execution towards the target PSCell and the reception of the latest conditional reconfiguration for this target PSCell. Actual value = field value * 100ms. The maximum value 1023 means 102.3s or longer.

[0061]

[0062] The OtherConfig field descriptions includes the mn-InitiatedPSCellChange field indicates whether the PSCell change procedure included in the RRCReconfiguration message is MN initiated or not.

[0063] The 3GPP V18.0.0 version of TS 38.331, TS 38.321, TS 38.300 and TS 38.304 can be considered as relevant background for embodiments as disclosed herein.

[0064] Under subsequent CPAC activation, Subsequent Conditional PSCell Addition or Change (subsequent CPAC / SCPAC) is defined as a conditional PSCell addition or change procedure that is executed after a PSCell addition, a PSCell change, a PCell change or an SCG release based on pre-configured subsequent CPAC configuration of candidate PSCell(s) without reconfiguration and re-initiation of CPC / CPA. The UE keeps the configured subsequent CPAC configuration (unless the network indicates to release it) and evaluates the execution conditions of candidate PSCells after completion of a PSCell addition, a PSCell change, a PCell change or an SCG release. Intra-SN subsequent CPAC initiated by the SN, inter-SN subsequent CPAC initiated by either MN or SN are supported.

[0065] 5.3.5.13.6 Subsequent CPAC reference configuration addition / removal:

[0066] The UE shall:

[0067] 1> if the scpac-ReferenceConfiguration is set to setup:

[0068] 2> if scpac-ReferenceConfiguration exists within the VarConditionalReconfig:

[0069] 3> replace the scpac-ReferenceConfiguration within the VarConditionalReconfig;

[0070] 2> else:

[0071] 3> store the scpac-ReferenceConfiguration within the VarConditionalReconfig;

[0072] 1> else (if scpac-ReferenceConfiguration is set to release):

[0073] 2> remove the scpac-ReferenceConfiguration within the VarConditionalReconfig;

[0074] 5.3.5.13.7 sk-Counter configuration addition / modification / removal

[0075] The UE shall:

[0076] 1> for each securityCellSetId received in the sk-CounterConfigToAddModList IE:

[0077] 2> if an entry with the matching securityCellSetId exists in the sk-CounterConfigToAddModList within the VarConditionalReconfig:

[0078] 3> replace the sk-CounterList within the VarConditionalReconfig with the sk-CounterList according to the received securityCellSetId;

[0079] 2> else:

[0080] 3> add a new entry for this securityCellSetId within the VarConditionalReconfig;

[0081] 1> for each securityCellSetId value included in the sk-CounterConfigToRemoveList that is part of the current sk-CounterConfigToAddModList in VarConditionalReconfig:

[0082] 2> remove the entry with the matching securityCellSetId from the sk-CounterConfigToAddModList;

[0083] 5.3.5.13.8Subsequent CPAC execution

[0084] Upon the conditional reconfiguration execution for subsequent CPAC, the UE shall:

[0085] 1> if the selected subsequent CPAC candidate configuration is stored in MCG VarConditionalReconfig:

[0086] 2> release / clear all current dedicated radio configuration except for the following:

[0087] - the MCG C-RNTI;

[0088] - the AS security configurations associated with the master key and the secondary key;

[0089] - for each SRB / DRB in current UE configuration:

[0090] - keep the associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0091] - release all fields related to the SRB / DRB configuration except for srb-Identity and drb-Identity;

[0092] - the UE variables VarConditionalReconfig and VarServingSecurityCellSetID.

[0093] 2> release / clear all current common radio configuration;

[0094] 1> else:

[0095] 2> release / clear all current dedicated radio configuration associated with the SCG except for the following:

[0096] - the AS security configurations associated with the secondary key;

[0097] - for each SRB / DRB in current UE configuration which is using the secondary key:

[0098] - keep the associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0099] - release all fields related to the SRB / DRB configuration except for srb-Identity and drb-Identity;

[0100] - the UE variables VarConditionalReconfig.

[0101] 2> release / clear all current common radio configuration associated with the SCG;

[0102] 1> use the default values specified in 9.2.3 for timers T310, T311 and constants N310, N311 for the cell group for which the subsequent CPAC cell switch procedure is triggered;

[0103] 1> if the securityCellSetId is included in the entry in VarConditionalReconfig containing the RRCReconfiguration message:

[0104] 2> if servingSecurityCellSetId is not included within VarServingSecurityCellSetID; or

[0105] 2> if the value of the securityCellSetId is not equal to the value of servingSecurityCellSetId within VarServingSecurityCellSetID:

[0106] 3> consider the first sk-Counter value in the sk-CounterList associated with the securityCellSetId within the VarConditionalReconfig as the selected sk-Counter value, and perform security key update procedure as specified in 5.3.5.7;

[0107] 3> remove the selected sk-Counter value from the sk-CounterList associated with the securityCellSetId within the VarConditionalReconfig;

[0108] 3> if the current VarServingSecurityCellSetID includes servingSecurityCellSetId:

[0109] 4> replace the value of servingSecurityCellSetId within VarServingSecurityCellSetID with the value of securityCellSetId associated with the selected cell;

[0110] 3> else:

[0111] 4> store the servingSecurityCellSetId within VarServingSecurityCellSetID with the value of securityCellSetId associated with the selected cell;

[0112] 1> if the selected subsequent CPAC candidate configuration is stored in the SCG

[0113] 4> trigger the PDCP entity of the AM DRB to perform PDCP data recovery as specified in TS 38.323;

[0114] 4> re-establish the corresponding RLC entity as specified in TS 38.322;

[0115] 1> if scpac-ConfigComplete is not included within the VarConditionalReconfig for the selected cell:

[0116] 2> if the subsequent CPAC candidate cell configuration is stored in MCG VarConditionalReconfig:

[0117] 3> consider scpac-ReferenceConfiguration in MCG VarConditionalReconfig to be the current UE configuration;

[0118] 2> else:

[0119] 3> consider scpac-ReferenceConfiguration in SCG VarConditionalReconfig to be the current SCG configuration;

[0120] When the UE considers the reference configuration to be the current UE configuration, the UE should store fields and configurations that are part of the reference configuration but should not execute any actions or procedures triggered by the reception of an RRCReconfiguration message which are described in clause 5.3.5.3.

[0121] 1> apply the stored condRRCReconfig of the selected cell(s) and perform the actions as specified in 5.3.5.3;

[0122] 1> release the radio bearer(s) and the associated logical channel(s) that are part of the current UE configuration but not part of the subsequent CPAC candidate configuration for the selected cell, or the subsequent CPAC reference configuration (in case the subsequent CPAC candidate configuration does not include scpac-ConfigComplete).

[0123] When scpac-ConfigComplete is not included for the selected cell, before a subsequent CPAC execution, a UE implementation may generate and store an RRC reconfiguration message by applying the received subsequent CPAC candidate configuration on top of the subsequent CPAC reference configuration, and the stored RRC reconfiguration message is applied for subsequent CPAC execution.

[0124] RRCReconfiguration can include scpac-ReferenceConfiguration, which includes the reference configuration associated with the SCG for the candidate supporting subsequent CPAC.

[0125] CondReconfigToAddModList information element:

[0126]

[0127]

[0128] CondReconfigToAddMod field descriptions may include condExecutionCond, the execution condition that needs to be fulfilled in order to trigger the execution of a conditional reconfiguration for CHO, CPA, intra-SN CPC without MN involvement, MN initiated inter-SN CPC, or SN initiated intra-SN subsequent CPAC without MN involvement. When configuring 2 triggering events (Meas Ids) for a candidate cell, the network ensures that both refer to the same measObject. The network configures at most one from condEventD1, condEventD2 or condEventT1 for the same candidate cell. For CPA and for MN-initiated inter-SN CPC, the network only indicates MeasId(s) associated with condEventA4. For intra-SN CPC and intra-SN subsequent CPAC, the network only indicates MeasId(s) associated with condEventA3 or condEventA5.

[0129] The condExecutionCondPSCell, the execution condition that needs to be fulfilled for the associated PSCell in order to trigger the execution of a conditional reconfiguration for CHO with candidate SCG(s). The Meas Ids refer to the measConfig associated with the MCG. When configuring for triggering events (Meas Ids) for a candidate cell, network ensures that both refer to the same measObject. The network only indicates MeasId(s) associated with condEventA4.

[0130] The condExecutionCondSCG, contains execution condition that needs to be fulfilled in order to trigger the execution of a conditional reconfiguration for SN initiated inter-SN CPC, SN initiated inter-SN subsequent CPAC, SN initiated intra-SN subsequent CPAC with MN involvement, or MN initiated inter-SN subsequent CPAC. The Meas Ids refer to the measConfig associated with the SCG. When configuring 2 triggering events (Meas Ids) for a candidate cell, network ensures that both refer to the same measObject. For each condReconfigId, the network always configures either condExecutionCond or condExecutionCondSCG (not both). The network only indicates MeasId(s) associated with condEventA3 or condEventA5.

[0131] condRRCReconfig: The RRCReconfiguration message to be applied when the condition(s) are fulfilled. The RRCReconfiguration message contained in condRRCReconfig cannot contain the field conditionalReconfiguration or the field daps-Config.

[0132] The scpac-ConfigComplete field indicates whether the configuration contained in condRRCReconfig for subsequent CPAC is a complete configuration.

[0133] The subsequentCondReconfig field contains the execution conditions that need to be fulfilled in order to trigger the execution of a subsequent CPAC. If the field is configured, the configuration of candidate PSCells for subsequent CPAC is supported. The subsequent execution condition is used for conditional reconfiguration evaluation for other candidate cells when the RRCReconfiguration message contained in condRRCReconfig has been applied.

[0134] In the conditional presence, condReconfigAdd field is mandatory present when a condReconfigId is being added. Otherwise, the field is optional, need M.

[0135] For the conditionalReconfiguration, the IE ConditionalReconfiguration is used to add, modify and release the configuration of conditional reconfiguration.

[0136] ConditionalReconfiguration information element

[0137]

[0138]

[0139] In the ConditionalReconfiguration field descriptions, if attemptCondReconfig present, the UE shall perform conditional reconfiguration if selected cell is a target candidate cell and it is the first cell selection after failure as described in clause 5.3.7.3.

[0140] The condReconfigToAddModList is the list of the configuration of candidate SpCells to be added or modified for CHO, CPA or CPC.

[0141] The condReconfigToRemoveList is the list of the configuration of candidate SpCells to be removed.

[0142] The scpac-ReferenceConfiguration includes the reference configuration for the candidate supporting subsequent CPAC.

[0143] The securityCellSetId field is used to determine whether UE should perform security update when conditional reconfiguration containing subsequentCondReconfig is executed.

[0144] The servingSecurityCellSetId field identifies the security cell set for serving PSCell.

[0145] The sk-counterConfiguration includes a list of sk-Counter used to derive S-KgNB for inter-SN subsequent CPAC. If this field is configured, the network shall not configure the field sk-Counter within the RRCReconfiguration message for conditional reconfiguration execution for subsequent CPAC.

[0146] Under conditional presence, the field CHO is optional, Need R, if the UE is configured with at least a candidate SpCell for CHO. Otherwise, the field is not present.

[0147] The condInitialSCPAC field is mandatory present upon the initial conditional reconfiguration which includes at least one inter-SN candidate PSCell supporting subsequent CPAC. Otherwise, the field is optional, need M.

[0148] The exact time of generation and storage of the complete RRC reconfiguration message based on the reference configuration is left to the UE implementation. However, it is possible that RRCReconfiguration message sent from the network also allows modification of Reference configuration. When it happens, if the UE has already generated complete configuration, the UE and network may be un-synchronized as network cannot know which reference configuration the UE has applied. To avoid this, the network may have to reconfgure the candidate configuration(s) by releasing and adding the configuration(s). This will lead to additional signalling on the network interfaces and the air interface.

[0149] Hence, there is a need in the art for solutions which will overcome the above-mentioned drawback(s), among others.

[0150] The principal object of the embodiments herein is to disclose methods and systems (or wireless network) for configuring, reporting and releasing the configuration of a UE for reporting information related to successful PSCell Addition and Successful PSCell Change, wherein the information could be configured to be stored and reported in a report called Successful PSCell Report (SPR).

[0151] Another object of embodiments herein is to disclose that the UE sends an RRCReconfigurationComplete after a subsequent CPAC execution or Long-Term Mobility (LTM) cell switch execution.

[0152] Another object of embodiments herein is to handle the SPR configuration and LTM configuration after a subsequent CPAC.

[0153] Further object of embodiments herein is to manage a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in a user equipment (UE).

[0154] Another object of embodiments herein is to regenerate at least one stored Radio Resource Control (RRC) Re-configuration message (such as NR RRCReconfiguration message) for at least one SCPAC candidate configuration based on the determination, wherein the at least one candidate configuration is not complete SCPAC candidate configuration.

[0155] Another object of embodiments herein is to regenerate the stored RRC Re-configuration message by combining reference and candidate configurations for all candidates with incomplete SCPAC configurations when the reference configuration is modified by the network entity.

[0156] Another object of embodiments herein is to regenerate the stored RRC Re-configuration message by combining reference and candidate configurations specifically for candidates with incomplete SCPAC configurations when their respective candidate configuration is modified by the network entity.

[0157] Another object of embodiments herein is to ensure that the network entity (gNB) releases all non-complete candidate configurations when the reference configuration for the SCPAC is released.

[0158] Another object of embodiments herein is to retain the Successful PSCell Change or Addition Report (SPR) configuration and / or a sn-InitiatedPSCellChange flag during the SCPAC operations.

[0159] Based on the proposed method, the RRCReconfiguration message sent from the network entity also allows modification of Reference configuration. When it happens, if the UE has already generated complete configuration, the UE and network entity may be un-synchronized as the network cannot know which reference configuration the UE has applied. To avoid this, the network entity may have to reconfgure the candidate configuration(s) by releasing and adding the configuration. This will avoid to additional signalling on the network interfaces and the air interface.

[0160] The UE releases the current dedicated configuration so that the network entity knows exactly which configuration is used by the UE due to SCPAC. This also allows the UE to apply the reference configuration. Without releasing the dedicated configuration, the current configuration may interfere with the reference configuration and thus the UE and network entity will be unsynchronized with respect to the parameters. However when the UE releases the dedicated configuration, the UE will not be able to log SPR based on RLF timers (such as NR T310, T312) of the source cell. The SPR can only be logged using target cell's handover related timers (such as NR T304 timer) and this will seriously affect the optimization of too late handovers. Alternatives such as UE logging the SPR based on RLF timers configured by the target cell or reference configuration doesn't work well in heterogeneous networks as the cells may have different coverage.

[0161] Unless the network entity doesn't release the complete candidate configurations, UE will not be able to perform the LTM cell switch or will perform the LTM cell switch using a wrong version of the candidate configuration.

[0162] The proposed method allows the network entity to modify or release the reference configuration and candidate configuration without affecting the SCPAC execution. The proposed method allows the UE to report the near failure information (Succesful PSCell Change or addition information) during SCPAC execution or legacy PSCellAddition or PSCellChange. The Subsequent CPAC helps the network entity to optimise both internode and Uu signalling, and also helps to reduce the SCG failure by avoiding late configuration ( i.e. avoids too late handovers in the SCG)

[0163] Referring now to the drawings, and more particularly to FIGs. 1A through 10, where similar reference characters denote corresponding features consistently throughout the figures, there are shown at least one embodiment.

[0164] FIG. 1A is an example block diagram depicting the communication of a User Equipment (UE) 102 and a network entity 110 for managing the Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in a wireless communication network 100. As illustrated in FIG. 1, the wireless communication network 100 comprises the UE 102 and the network entity 110. The UE 102 communicates with the network entity 110.

[0165] The UE 102 referred to herein may be an electronic device / user device that is used by the user to connect, interact, and / or control the operations of the plurality of other devices using a 3GPP network. Examples of the UE 102 may include, but are not limited to, a smartphone, a mobile phone, a video phone, a computer, a tablet personal computer (PC), a laptop, a wearable device, television, a personal digital assistant (PDA), an IoT device, or any other device that may use a 3GPP network or non-3GPP network.

[0166] The network entity 110 may represent a network element that communicates with the UE 102. The network entity 110 sends a SCPAC reference configuration and at least one SCPAC candidate configuration to the UE 102 for managing a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration. The network entity 110 may modify the SCPAC reference configuration and at least one SCPAC candidate configuration. The usage of terms "network entity", "network", "network nodes (gNB)" can be interchangeably used and provides the same meaning.

[0167] The UE 102 receives the SCPAC reference configuration and at least one SCPAC candidate configuration from a network entity 110. The UE 102 generates and stores Radio Resource Control (RRC) Re-configuration messages by applying the SCPAC candidate configurations to the SCPAC reference configuration. The UE 102 determines if there are any modifications to the SCPAC reference or candidate configurations provided by the network entity 110. Upon detecting such modifications, the UE 102 regenerates the stored RRC Re-configuration messages for incomplete candidate configurations based on the updates. Further, regenerating the stored RRC Re-configuration messages is performed by the UE 102, wherein the UE 102 detects changes to the SCPAC reference configuration provided by the network entity 110. The UE 102 creates updated RRC Re-configuration messages by applying the modified SCPAC reference configuration to the non-complete conditional RRC reconfigurations (condRRCReconfig) for each SCPAC candidate configuration. The UE 102 replaces the stored RRC Re-configuration messages with the newly generated ones to ensure SCPAC execution aligns with the latest configurations provided by the network entity 110.

[0168] The UE 102 uses the stored RRC Re-configuration messages during SCPAC execution to perform the configuration. It ensures that the applied RRC Re-configuration messages are based on the latest SCPAC reference configuration (scpac-ReferenceConfiguration) and conditional RRC Re-configuration (condRRCReconfig), guaranteeing consistency with the most recent instructions of the network.

[0169] The UE 102 identifies any updates to the conditional RRC Re-configuration (condRRCReconfig) associated with a SCPAC candidate configuration. The UE 102 updates the stored RRC Re-configuration messages by applying the modified candidate configurations to the SCPAC reference configuration and replaces the old messages with updated ones, ensuring SCPAC execution aligns with the latest network instructions. Similar to the UE 102, the network entity 110 also ensures that the RRC configuration it applies for the UE 102 is according to the latest SCPAC candidate configuration and the SCPAC reference configuration.

[0170] The UE 102 releases the current dedicated configuration provided by the network entity 110. During this process, the UE 102 retains configurations such as the Successful PSCell Change or Addition Information Report (SPR) and the Secondary Node (SN)-initiated PSCellChange flag, if they are present in the current configuration. Further, the UE 102 determines the Successful PSCell Change or Addition Information Report (SPR) based on the retained SPR configuration and the SN-initiated PSCellChange flag. This ensures that critical information is preserved during SCPAC execution.

[0171] The network entity 110 transmits the RRC Re-configuration message to release the SCPAC reference configuration (scpac-ReferenceConfiguration). The network entity 110 releases conditional RRC Re-configuration messages for SCPAC candidate configurations that are not complete. Further, if candidate cells associated with non-complete configurations cannot be released, the network 110 ensures that the SCPAC reference configuration is not released. Thus, preventing inconsistencies during SCPAC execution. The network entity 110 is responsible for managing SCPAC configurations, that can be either a master node (MN) 110a or a secondary node (SN) 110b. This allows for flexibility in network architecture for SCPAC management.

[0172] In an embodiment, when the reference configuration for subsequent CPAC is modified, the UE 102 regenerates any stored RRC Re-configuration message that was previously generated by applying the previous reference configuration message to a condRRCReconfig for the SCPAC configuration, using the new scpac-ReferenceConfiguration. The UE 102 applies the modified scpac-ReferenceConfiguration to the non-complete condRRCReconfig for the SCPAC configurations. The newly generated RRC Re-configuration message replaces any stored RRC Re-configuration message that was generated by applying the previous scpac-ReferenceConfiguration to the non-complete condRRCReconfig for the SCPAC configurations.

[0173] In another embodiment, the UE 102 ensures that the RRC Re-configuration applied at the time of subsequent CPAC execution is based on the latest scpac-ReferenceConfiguration and condRRCReconfig for the SCPAC configuration.

[0174] In an embodiment, when a condRRCReconfig for the SCPAC configuration is modified by the network 110, the UE 102 regenerates any stored RRC Re-configuration message that was previously generated by applying the reference configuration message to a prior condRRCReconfig for the SCPAC configuration, using the new condRRCReconfig for the SCPAC configuration. The UE 102 applies the modified non-complete condRRCReconfig for the SCPAC configuration over the scpac-ReferenceConfiguration, and the newly generated RRC reconfiguration message replaces any stored RRC reconfiguration message that was generated by applying the scpac-ReferenceConfiguration to the previous non-complete condRRCReconfig for the subsequent CPAC configurations.

[0175] In an embodiment, handling the release of the reference configuration (scpac-ReferenceConfiguration) and associated candidate cells during subsequent CPAC management is handled by the network entity 110. The network entity (or network node) (e.g., gNB) 110 takes responsibility for ensuring that incomplete candidate configurations are appropriately handled.

[0176] If the scpac-ReferenceConfiguration is triggered by the master node (MN) 110a, the MN 110a releases all incomplete candidate configurations, that it originally configured. In scenarios where both the master node (MN) 110a and the secondary node (SN) 110b are involved, each node releases the incomplete candidate configurations that were configured by them individually. Similarly, if the scpac-ReferenceConfiguration is triggered by the secondary node (SN), the SN releases all incomplete configurations that it configured. In cases involving both the SN and MN, they jointly ensure that their respective incomplete configurations are released.

[0177] Hence, ensures that the scpac-ReferenceConfiguration is not released until all candidate cells are either released or confirmed as complete, maintaining the integrity of the SCPAC configurations.

[0178] In an embodiment, upon executing the conditional Re-configuration message for SCPAC, the UE 102 retains the configuration for the Successful PSCell Change or Addition Report (SPR configuration) if the conditional Re-configuration message is present in the current dedicated configuration.

[0179] In an embodiment, upon executing the conditional Re-configuration message for SCPAC, the UE 102 retains the configuration that indicates whether the SCPAC is MN-initiated or SN-initiated, if the conditional Re-configuration message is present in the current dedicated configuration (such as sn-InitiatedPSCellChange-r18 or mn-InitiatedPSCellChange-r18).

[0180] In an embodiment, if SRB3 is configured in the target cell, the UE 102 sends RRCReconfigurationComplete over SRB3 irrespective of the SRB where condRRCReconfig for the subsequent CPAC configuration or LTM candidate configuration or the reference configurations are received. If SRB3 is not configured in the target cell, the UE 102 sends RRCReconfigurationComplete over SRB1.

[0181] In an embodiment, SN RRC Reconfiguration Complete for indicating the LTM cell switch completion and the successful completion of subsequent CPAC messages is mapped to the same SRB as the message initiating the procedure. In an embodiment SRB of the message initiating the subsequent CPAC procedure is the SRB over which RRCReconfiguration message adding Subsequent CPAC configuration is received. In an embodiment SRB of the message initiating the subsequent CPAC procedure is the SRB over which RRCReconfiguration message which has performed the last modification of Subsequent CPAC configuration is received. In an embodiment SRB of the message initiating the subsequent CPAC procedure is the SRB over which RRCReconfiguration message adding SCPAC reference configuration is received. In an embodiment SRB of the message initiating the subsequent CPAC procedure is the SRB over which RRCReconfiguration message which has performed the last modification of SCPAC reference configuration is received.

[0182] In an embodiment, SN RRC Reconfiguration Complete for indicating the LTM cell switch completion is mapped to the same SRB as the message initiating the procedure. In an embodiment SRB of the message initiating the LTM cell switch procedure is the SRB over which RRCReconfiguration message adding LTM candidate configuration is received. In an embodiment SRB of the message initiating the LTM cell switch procedure is the SRB over which RRCReconfiguration message which has performed the last modification of LTM candidate configuration is received. In an embodiment SRB of the message initiating the LTM cell switch procedure is the SRB over which RRCReconfiguration message adding LTM reference configuration is received. In an embodiment SRB of the message initiating the LTM cell switch procedure is the SRB over which RRCReconfiguration message which has performed the last modification of LTM reference configuration is received.

[0183] In an embodiment, SN RRC Reconfiguration Complete for indicating the LTM cell switch completion and the successful completion of CPAC procedure is mapped to the same SRB as the message initiating the procedure. In an embodiment SRB of the message initiating the CPAC procedure is the SRB over which RRCReconfiguration message adding CPAC configuration is received. In an embodiment SRB of the message initiating the subsequent CPAC procedure is the SRB over which RRCReconfiguration message which has performed the last modification of CPAC configuration is received.

[0184] Handover Preparation Information:

[0185] In an embodiment, source gNB provides information to identify the current usage status of sk-counters for each SN (i.e. for each SecurityCellSetId) to the target gNB during a handover (through HandoverPreparationInformation Inter Node RRC message). Normally, Source gNB is MN source gNB and target gNB is MN target gNB and handover is PCell change. It is also possible to have that source gNB is SN source gNB and target gNB is SN target gNB and handover is PSCell change.

[0186] Information to identify the current usage status of sk-counters can be the list of sk-counters UE has already used, list of sk-counters UE has not yet used, count of sk-counters UE has already used, count of sk-counters UE has not yet used or any other information which helps the target gNB to identify the usage of sk-counters.

[0187] In an embodiment, for each SecuritySet (or for each SK-CounterConfig) source gNB informs the target gNB, the number of unused sk-counters. In an embodiment, AS-Context in HandoverPreparationInformation is used by source gNB to inform the target gNB the number of unused sk-counters for each SN. A sample change in TS 38.331 is given below.

[0188]

[0189]

[0190] unusedsk-CounterInfo: Provides information about the count of unused sk-counters for each SN. unusedSk-CounterCount in a UnusedSK-CounterInfo indicates the number of sk-counters in sk-CounterList-r18 configured for the UE 102 that are not yet used for the corresponding securityCellSetId in the same UnusedSK-CounterInfo.

[0191] In an embodiment, for each SecuritySet (or for each SK-CounterConfig) source gNB informs the target gNB, the number of used sk-counters. In an embodiment, AS-Context in HandoverPreparationInformation is used by source gNB to inform the target gNB the number of used sk-counters for each SN. A sample change in TS 38.331 is given below.

[0192]

[0193]

[0194] usedsk-CounterInfo: Provides information about the count of used sk-counters for each SN. usedSk-CounterCount in a usedSK-CounterInfo indicates the number of sk-counters in sk-CounterList-r18 configured for the UE 102 that are not yet used for the corresponding securityCellSetId in the same usedSK-CounterInfo.

[0195] In an embodiment, for each SecuritySet (or for each SK-CounterConfig) source gNB informs the target gNB, the list of unused sk-counters. In an embodiment, AS-Context in HandoverPreparationInformation is used by source gNB to inform the target gNB the list of unused sk-counters. A sample change in TS 38.331 is given below.

[0196]

[0197]

[0198] unusedsk-CounterList: Includes a list of SK-CounterConfig-r18. Each sk-CounterList within unusedsk-CounterList contains the list of sk-counters which are not yet used by the UE 102 to derive S-KgNB for inter-SN subsequent CPAC for the corresponding securityCellSetId.

[0199] In an embodiment, for each SecuritySet (or for each SK-CounterConfig) source gNB informs the target gNB, the list of used sk-counters. In an embodiment, AS-Context in HandoverPreparationInformation is used by the source gNB to inform the target gNB the list of used sk-counters. A sample change in TS 38.331 is given below.

[0200]

[0201]

[0202] unusedsk-CounterList: Includes a list of SK-CounterConfig-r18. Each sk-CounterList within unusedsk-CounterList contains the list of sk-counters which are not yet used by the UE 102 to derive S-KgNB for inter-SN subsequent CPAC for the corresponding securityCellSetId.

[0203] In an embodiment, for each SecuritySet (or for each SK-CounterConfig) source gNB informs the target gNB, the list of used sk-counters. In an embodiment, AS-Context in HandoverPreparationInformation is used by source gNB to inform the target gNB the list of used sk-counters. A sample change in TS 38.331 is given below.

[0204]

[0205]

[0206] usedsk-CounterList: Includes a list of SK-CounterConfig-r18. Each sk-CounterList within usedsk-CounterList contains the list of sk-counters which are already used by the UE 102 to derive S-KgNB for inter-SN subsequent CPAC for the corresponding securityCellSetId.

[0207] With each Inter-SN CPAC execution, the UE 102 uses one sk-counter from the sk-counter list corresponding to the SecurityCellSetId and may also remove the sk-counter from the sk-counter list. The source MN gNB keeps track of this usage and provides information to identify the current usage status of sk-counters.

[0208] The target MN gNB uses the received information from source MN gNB to maintain the list of sk-counters which can be used by the UE 102 for further Inter-SN subsequent CPAC executions. With each Inter-SN CPAC execution, the UE 102 uses one sk-counter from the sk-counter list corresponding to the SecurityCellSetId and may also remove the sk-counter from the sk-counter list. The MN may provide a new sk-counterlist corresponding to the SecutityCellSetId before the list becomes empty. When target MN becomes source MN for the next handover, it also provides information to identify the current usage status of sk-counters for each SN to the new target MN.

[0209] In an embodiment, the SN (110b) maintains the list of used sk-counters and applies a new sk-counter each time there is an inter-SN PSCellchange where any of its cells are the target cells. If the sk-counter list becomes empty, the SN (110b) may request the MN to provide a new sk-counterlist.

[0210] Reference Configuration modification for SCPAC:

[0211] In an embodiment, when the Reference configuration for subsequent CPAC is modified, the UE 102 regenerates any stored RRC reconfiguration message which was generated by applying the previous reference configuration message on a condRRCReconfig for the subsequent CPAC configuration using the new scpac-ReferenceConfiguration. The UE 102 applies the modified scpac-ReferenceConfiguration over the non-complete condRRCReconfig for the subsequent CPAC configurations and the generated RRC reconfiguration replaces any stored RRC Reconfiguration generated by applying the previous scpac-ReferenceConfiguration over the non-complete condRRCReconfig for the subsequent CPAC configurations.

[0212] In an embodiment, according to TS 38.331: 5.3.5.13.6 Subsequent CPAC reference configuration addition / removal

[0213] The UE 102 shall:

[0214] 1> if the scpac-ReferenceConfiguration is set to setup:

[0215] 2> if scpac-ReferenceConfiguration exists within the VarConditionalReconfig:

[0216] 3> replace the scpac-ReferenceConfiguration within the VarConditionalReconfig;

[0217] 3> replace any stored RRC reconfiguration based on previous scpac-ReferenceConfiguration.

[0218] 2> else:

[0219] 3> store the scpac-ReferenceConfiguration within the VarConditionalReconfig;

[0220] 1> else (if scpac-ReferenceConfiguration is set to release):

[0221] 2> remove the scpac-ReferenceConfiguration within the VarConditionalReconfig;

[0222] When scpac-ConfigComplete is not included for the selected cell, before a subsequent CPAC execution, the UE implementation may generate and store an RRC reconfiguration message by applying the received subsequent CPAC candidate configuration on top of the subsequent CPAC reference configuration, and the stored RRC reconfiguration message is applied for subsequent CPAC execution. The UE 102 ensures that the RRC reconfiguration applied at the time of subsequent CPAC execution in in accordance with the latest scpac-ReferenceConfiguration and condRRCReconfig for the subsequent CPAC configuration.

[0223] In an embodiment, when a condRRCReconfig for the subsequent CPAC configuration is modified by the network, the UE 102 regenerates any stored RRC reconfiguration message which was generated by applying the reference configuration message on a previous condRRCReconfig for the subsequent CPAC configuration using the new condRRCReconfig for the subsequent CPAC configuration. The UE 102 applies the modified non-complete condRRCReconfig for the subsequent CPAC configuration over the scpac-ReferenceConfiguration and the generated RRC reconfiguration replaces any stored RRC Reconfiguration generated by applying the scpac-ReferenceConfiguration over the previous non-complete condRRCReconfig for the subsequent CPAC configurations.

[0224] Reference Configuration release for SCPAC:

[0225] In an embodiment, when the Reference configuration for subsequent CPAC is releases, the UE 102 releases any stored RRC reconfiguration message which was generated by applying the previous reference configuration message on a condRRCReconfig for the subsequent CPAC configuration.

[0226] In an embodiment, according to TS 38.331, 5.3.5.13.6 Subsequent CPAC reference configuration addition / removal

[0227] The UE 102 shall:

[0228] 1> if the scpac-ReferenceConfiguration is set to setup:

[0229] 2> if scpac-ReferenceConfiguration exists within the VarConditionalReconfig:

[0230] 3> replace the scpac-ReferenceConfiguration within the VarConditionalReconfig;

[0231] 3> replace any stored RRC reconfiguration based on previous scpac-ReferenceConfiguration.

[0232] 2> else:

[0233] 3> store the scpac-ReferenceConfiguration within the VarConditionalReconfig;

[0234] 1> else (if scpac-ReferenceConfiguration is set to release):

[0235] 2> remove the scpac-ReferenceConfiguration within the VarConditionalReconfig;

[0236] 2> release any - stored RRC reconfiguration based on previous scpac-ReferenceConfiguration

[0237] gNB methods for configuring reference configuration:

[0238] In an embodiment, while sending an RRC Reconfiguration message such as NR RRCReconfiguration which releases the reference configuration for subsequent CPAC (scpac-ReferenceConfiguration in the background), the network entity (gNB) 110 releases all the candidate cells (condRRCReconfig for the subsequent CPAC configuration) which are not having complete configuration. If the candidate cells cannot be released, the gNB ensures that scpac-ReferenceConfiguration is not released. In an embodiment herein, scpac-ReferenceConfiguration may be triggered by MN and MN releases all the candidate cells (condRRCReconfig for the subsequent CPAC configuration) which are not having complete configuration configured by MN. In an embodiment scpac-ReferenceConfiguration may be triggered by MN and both SN and MN respectively releases all the candidate cells (condRRCReconfig for the subsequent CPAC configuration) which are not having complete configuration configured by themselves.

[0239] In an embodiment, scpac-ReferenceConfiguration may be triggered by the SN (110b) and the SN (110b) releases all the candidate cells (condRRCReconfig for the subsequent CPAC configuration) which are not having complete configuration configured by the SN (110b). In an embodiment scpac-ReferenceConfiguration may be triggered by the SN (110b) and both SN (110b) and MN (110a) respectively releases all the candidate cells (condRRCReconfig for the subsequent CPAC configuration) which are not having complete configuration configured by themselves.

[0240] In an embodiment, the network entity 110 such as gNB in NR which implements Subsequent CPAC, upon adding candidate cells for subsequent CPAC for the first time in the UE 102 where in at least one of those subsequent CPAC candidate cells are configured with non-completeconfiguration (i.e. at least one of the SCPAC candidate cells are not having complete configuration), sends the SCPAC reference configuration (scpac-ReferenceConfiguration) to the UE 102. The gNB in the above embodiment can be either MN (110a) or the SN (110b). gNB (MN or SN) also ensures that if there is a SCPAC candidate cell configured without a complete configuration (condRRCReconfig for the subsequent CPAC configuration is provided without complete configuration), the UE 102 will be provided with the scpac-ReferenceConfiguration.

[0241] SCPAC execution:

[0242] In an embodiment, upon the conditional reconfiguration execution for subsequent CPAC, the UE 102 keeps the configuration for Successful PSCell Change or Addition Report (SPR configuration) if it is present in the current dedicated configuration.

[0243] Upon the conditional reconfiguration execution for subsequent CPAC, the UE 102 shall:

[0244] 1> if the selected subsequent CPAC candidate configuration is stored in MCG VarConditionalReconfig:

[0245] 2> release / clear all current dedicated radio configuration except for the following:

[0246] - the MCG C-RNTI;

[0247] - the AS security configurations associated with the master key and the secondary key;

[0248] - for each SRB / DRB in current UE configuration:

[0249] - keep the associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0250] - release all fields related to the SRB / DRB configuration except for srb-Identity and drb-Identity;

[0251] - the UE 102 variables VarConditionalReconfig and VarServingSecurityCellSetID.

[0252] - successful PSCell change or addition report configuration.

[0253] 2> release / clear all current common radio configuration;

[0254] 1> else:

[0255] 2> release / clear all current dedicated radio configuration associated with the SCG except for the following:

[0256] - the AS security configurations associated with the secondary key;

[0257] - for each SRB / DRB in current UE configuration which is using the secondary key:

[0258] - keep the associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0259] - release all fields related to the SRB / DRB configuration except for srb-Identity and drb-Identity;

[0260] - the UE 102 variables VarConditionalReconfig.

[0261] - successful PSCell change or addition report configuration.

[0262] 2> release / clear all current common radio configuration associated with the SCG;

[0263] In an embodiment, SPR configuration is configured by MN. In an embodiment, the UE 102 logs SPR based on this retained configuration and later releases the SPR configuration after a subsequent CPAC execution.

[0264] In an embodiment, upon the conditional reconfiguration execution for subsequent CPAC, the UE 102 keeps the configuration which informs whether the subsequent CPAC is MN initiated or the SN initiated if it is present in the current dedicated configuration (such as sn-InitiatedPSCellChange-r18 or mn-InitiatedPSCellChange-r18).

[0265] Upon the conditional reconfiguration execution for subsequent CPAC, the UE 102 shall:

[0266] 1> if the selected subsequent CPAC candidate configuration is stored in MCG VarConditionalReconfig:

[0267] 2> release / clear all current dedicated radio configuration except for the following:

[0268] - the MCG C-RNTI;

[0269] - the AS security configurations associated with the master key and the secondary key;

[0270] - for each SRB / DRB in current UE configuration:

[0271] - keep the associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0272] - release all fields related to the SRB / DRB configuration except for srb-Identity and drb-Identity;

[0273] - the UE 102 variables VarConditionalReconfig and VarServingSecurityCellSetID.

[0274] - the sn-InitiatedPSCellChange-r18

[0275] - the mn-InitiatedPSCellChange-r18

[0276] 2> release / clear all current common radio configuration;

[0277] 1> else:

[0278] 2> release / clear all current dedicated radio configuration associated with the SCG except for the following:

[0279] - the AS security configurations associated with the secondary key;

[0280] - for each SRB / DRB in current UE configuration which is using the secondary key:

[0281] - keep the associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0282] - release all fields related to the SRB / DRB configuration except for srb-Identity and drb-Identity;

[0283] - the UE variables VarConditionalReconfig.

[0284] - successful PSCell change or addition report configuration.

[0285] - the sn-InitiatedPSCellChange-r18

[0286] - the mn-InitiatedPSCellChange-r18

[0287] 1> if scpac-ConfigComplete is not included within the VarConditionalReconfig for the selected cell:

[0288] 2> if the subsequent CPAC candidate cell configuration is stored in MCG VarConditionalReconfig:

[0289] 3> consider scpac-ReferenceConfiguration in MCG VarConditionalReconfig to be the current UE configuration except for SPR configuration;

[0290] 2> else:

[0291] 3> consider scpac-ReferenceConfiguration in SCG VarConditionalReconfig to be the current SCG configuration except for SPR configuration;

[0292] In an embodiment, upon the conditional reconfiguration execution for subsequent CPAC, the UE 102 keeps the LTM configuration. In an embodiment, the ltm configuration is the LTM configuration associated to SCG. In an embodiment, the ltm configuration is the LTM configuration associated to MCG.

[0293] Upon the conditional reconfiguration execution for subsequent CPAC, the UE 102 shall:

[0294] 1> if the selected subsequent CPAC candidate configuration is stored in MCG VarConditionalReconfig:

[0295] 2> release / clear all current dedicated radio configuration except for the following:

[0296] - the MCG C-RNTI;

[0297] - the AS security configurations associated with the master key and the secondary key;

[0298] - for each SRB / DRB in current UE configuration:

[0299] - keep the associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0300] - release all fields related to the SRB / DRB configuration except for srb-Identity and drb-Identity;

[0301] - the UE variables VarConditionalReconfig and VarServingSecurityCellSetID.

[0302] - the ltm-config

[0303] 2> release / clear all current common radio configuration;

[0304] 1> else:

[0305] 2> release / clear all current dedicated radio configuration associated with the SCG except for the following:

[0306] - the AS security configurations associated with the secondary key;

[0307] - for each SRB / DRB in current UE configuration which is using the secondary key:

[0308] - keep the associated RLC, PDCP and SDAP entities, their state variables, buffers and timers;

[0309] - release all fields related to the SRB / DRB configuration except for srb-Identity and drb-Identity;

[0310] - the UE variables VarConditionalReconfig.

[0311] - successful PSCell change or addition report configuration.

[0312] - the ltm-config

[0313] FIG. 1B shows various hardware components of the UE (102), according to embodiments as disclosed herein. In an embodiment, the UE (102) includes a processor (210), a communicator (220), a memory (230), and a SCPAC managing controller (240). The processor (210) is coupled with the communicator (220), the memory (230), and the SCPAC managing controller (240).

[0314] The SCPAC managing controller (240) receives the SCPAC reference configuration and the at least one SCPAC candidate configuration from the network entity (110). Further, the SCPAC managing controller (240) generates and stores the at least one RRC Re-configuration message by applying the at least one SCPAC candidate configuration on the SCPAC reference configuration.

[0315] Further, the SCPAC managing controller (240) determines that at least one of: that the SCPAC reference configuration and at least one SCPAC candidate configuration is modified by the network entity (110).

[0316] Further, the SCPAC managing controller (240) regenerates the stored at least one RRC Re-configuration message for at least one SCPAC candidate configuration based on the determination, wherein the at least one candidate configuration is not complete SCPAC candidate configuration.

[0317] In an embodiment, the SCPAC managing controller (240) detects the at least one modification to the reference configuration for the SCPAC provided by the network entity (110). Further, the SCPAC managing controller (240) generates the updated RRC Re-configuration message(s) by applying the modified SCPAC reference configuration (e.g., scpac-ReferenceConfiguration) to the non-complete conditional RRCReconfiguration message (e.g., condRRCReconfig) for each of the subsequent CPAC candidate configurations. Further, the SCPAC managing controller (240) replaces each of the stored RRC Re-configuration message(s) with the updated RRC Re-configuration message(s) to ensure that the SCPAC is executed using the latest scpac-ReferenceConfiguration and the condRRCReconfig provided by the network entity (110).

[0318] In an embodiment, the SCPAC managing controller (240) detects the at least one modification to the conditional RRC Re-configuration (e.g., condRRCReconfig) associated with the SCPAC candidate configuration, provided by the network entity (110). Further, the SCPAC managing controller (240) generates the updated RRC Re-configuration message by applying the modified condRRCReconfig to the scpac-ReferenceConfiguration for the subsequent CPAC configuration. Further, the SCPAC managing controller (240) replaces the at least one stored RRC Re-configuration message with the generated RRC Re-configuration message. The subsequent CPAC is executed in accordance with a scpac-ReferenceConfiguration and a condRRCReconfig provided by the network entity (110).

[0319] Further, the SCPAC managing controller (240) applies the at least one stored RRC Re-configuration message during the SCPAC execution to perform SCPAC. Further, the SCPAC managing controller (340) ensures the RRC Re-configuration message applied at the time of SCPAC execution is based on the latest received scpac-ReferenceConfiguration and condRRCReconfig for the SCPAC configuration.

[0320] In an embodiment, the SCPAC managing controller (240) executes the SCPAC by using the relevant configurations. Further, the SCPAC managing controller (240) releases the current dedicated configuration. The UE (102) retains the configuration for at least one of: the Successful PSCell Change or Addition Information Report (SPR) configuration and the SN initiated PSCellChange flag in the release, when at least one of the SPR configuration and SN initiated PSCellChange flag is present in a current dedicated configuration provided by the network entity (110). In an embodiment, the SCPAC managing controller (240) determines SPR based on at least one of the retained SPR configuration and SN initiated PSCellChange flag.

[0321] The SCPAC managing controller (240) is implemented by analog and / or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and may optionally be driven by firmware.

[0322] The processor (210) may include one or a plurality of processors. The one or the plurality of processors may be a general-purpose processor, such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and / or an AI-dedicated processor such as a neural processing unit (NPU). The processor (210) may include multiple cores and is configured to execute the instructions stored in the memory (230).

[0323] Further, the processor (210) is configured to execute instructions stored in the memory (230) and to perform various processes. The communicator (220) is configured for communicating internally between internal hardware components and with external devices via one or more networks. The memory (230) also stores instructions to be executed by the processor (210). The memory (230) may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the memory (230) may, in some examples, be considered a non-transitory storage medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term "non-transitory" should not be interpreted that the memory (230) is non-movable. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache).

[0324] Although FIG. 1B shows various hardware components of the UE (102) but it is to be understood that other embodiments are not limited thereon. In other embodiments, the UE (102) may include less or more number of components. Further, the labels or names of the components are used only for illustrative purposes and does not limit the scope of the invention. One or more components can be combined together to perform the same or substantially similar function in the UE (102).

[0325] FIG. 1C shows various hardware components of the network entity (110), according to embodiments as disclosed herein. The network entity (110) is at least one of a master node (MN) 110a and a secondary node (SN) 110b. In an embodiment, the network entity (110) includes a processor (310), a communicator (320), a memory (330), and a SCPAC managing controller (340). The processor (310) is coupled with the communicator (320), the memory (330), and the SCPAC managing controller (340).

[0326] The SCPAC managing controller (340) transmits the RRC Re-configuration message to release a reference configuration (e.g., scpac-ReferenceConfiguration) for the subsequent CPAC configuration. Further, the SCPAC managing controller (340) releases the at least one conditional RRC Re-configuration message of the SCPAC configuration. The at least one conditional RRC Re-configuration message is not complete SCPAC configuration.

[0327] When at least one candidate cell associated with the at least one conditional RRC Re-configuration message is not released, the SCPAC managing controller (340) ensures that a scapac-ReferenceConfiguration is not released.

[0328] The SCPAC managing controller (340) is implemented by analog and / or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and may optionally be driven by firmware.

[0329] The processor (310) may include one or a plurality of processors. The one or the plurality of processors may be a general-purpose processor, such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and / or an AI-dedicated processor such as a neural processing unit (NPU). The processor (310) may include multiple cores and is configured to execute the instructions stored in the memory (330).

[0330] Further, the processor (310) is configured to execute instructions stored in the memory (330) and to perform various processes. The communicator (320) is configured for communicating internally between internal hardware components and with external devices via one or more networks. The memory (330) also stores instructions to be executed by the processor (310). The memory (330) may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the memory (330) may, in some examples, be considered a non-transitory storage medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term "non-transitory" should not be interpreted that the memory (330) is non-movable. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache).

[0331] Although FIG. 1C shows various hardware components of the network entity (110) but it is to be understood that other embodiments are not limited thereon. In other embodiments, the network entity (110) may include less or more number of components. Further, the labels or names of the components are used only for illustrative purposes and does not limit the scope of the invention. One or more components can be combined together to perform the same or substantially similar function in the network entity (110).

[0332] FIG. 2 is an example diagram S200 depicting the method for handling the scpac-ReferenceConfiguration. As illustrated in FIG. 2, in step S202, the UE 102 may receive spac-ReferenceConfiguration. In step S204, the UE 102 may generate and store RRC Re-configuration message by applying the received subsequent non-complete CPAC candidate configuration on top of the spac-ReferenceConfigurationDeregistration from the network 110.

[0333] In step S206, the UE 102 receive information to modify spac-ReferenceConfiguration or subsequent candidate configuration. Finally in step S208, the UE 102 may regenerate RRC Re-configuration message by applying the received subsequent non-complete CPAC candidate configuration on top of the scpac-ReferenceConfiguration.

[0334] FIG. 3 is an example diagram S300 depicting the method for releasing the scpac-ReferenceConfiguration. As illustrated in FIG. 3, in step S302, the UE 102 may receive spac-ReferenceConfiguration. In step S304, the UE 102 may generate and store RRC Re-configuration message by applying the received subsequent non-complete CPAC candidate configuration on top of the spac-ReferenceConfigurationDeregistration from the network 110.

[0335] In step S306, the UE 102 receive information to release spac-ReferenceConfiguration or subsequent candidate configuration. Finally in step 308, the UE 102 may release stored RRC Re-configuration message which was generated by applying the subsequent non-complete CPAC candidate configuration on top of the scpac-ReferenceConfiguration.

[0336] FIG. 4 is an example diagram S400 depicting the method for executing SCPACs. As illustrated in FIG. 4, in step S402, SCPAC is executed, in step S404, dedicated configuration is released except a subset of configuration including SPR config, mn-initiatedPSCellChange, sn-InitiatedPSCellChnage and Itm-Config.

[0337] FIG. 5 is an example diagram S500 depicting the method for managing a Subsequent Conditional Primary Secondary Cell Group (SCG) Cell Addition or Change (SCPAC) configuration in the user equipment (UE). In step S502, the UE 102 receive the SCPAC reference configuration and at least one SCPAC candidate configuration from a network entity (110). In step S504, the UE generates and stores the at least one Radio Resource Control (RRC) Re-configuration message by applying the at least one SCPAC candidate configuration on the SCPAC reference configuration. In step S506, the UE 102 determine that at least one of: the SCPAC reference configuration and the at least one SCPAC candidate configuration is modified by the network entity (110). In step S508, the UE 102 regenerates the stored at least one RRC Re-configuration message for at least one SCPAC candidate configuration based on the determination, wherein the at least one candidate configuration is not complete SCPAC candidate configuration.

[0338] FIG. 6 is an example diagram S600 depicting the method for executing a Subsequent Conditional Primary Secondary CellGroup (SCG) Cell Addition or Change (SCPAC) in the user equipment (UE). In step S602, the UE 102 executes the SCPAC by using the relevant configurations. In step S604, the UE 102 releases the current dedicated configuration, wherein the UE (102) retains the configuration for at least one of: the Successful PSCell Change or Addition Information Report (SPR) configuration and the SN (110b) initiated PSCellChange flag in the release, when at least one of the SPR configuration and SN initiated PSCellChange flag is present in a current dedicated configuration provided by a network entity (110).

[0339] FIG. 7 is an example diagram S700 depicting the method for managing SCPAC configuration in the UE 102 using the network entity 110. In step S702, the network 110 transmit a Radio Resource Control (RRC) Re-configuration message to release a reference configuration (scpac-ReferenceConfiguration) for a subsequent CPAC configuration. In step S704, the network entity 110 release at least one conditional RRC Re-configuration message of the SCPAC configuration, wherein the at least one conditional RRC Re-configuration message is not complete SCPAC configuration.

[0340] FIG. 8 is an example diagram S800 depicting the method for releasing conditional execution conditions for the SCPAC. As illustrated in FIG. 8, in step S802, the UE 102 may receive RRC message with condExecutionCondToReleaseList including condReconfig value that is not part of current UE configuration. In step S804, the UE 102 do not consider the received message as erroneous. Finally in step S806, the UE 102 may send RRC complete message to the network 110.

[0341] FIG. 9 is an example diagram (S300) depicting the method for managing SCGFailureInformation and SCPAC. As illustrated in FIG. 9, in step S902, the SCGFailure during PSCellChange or PSCellAddition for selective CPAC is performed. In step S904, the UE 102 may include information in SCGFailureInformation that the PSCellChange or PSCellAddition was due to selective CPAC and include other information for optimization. Finally in step S906, the UE 102, may send SCGFailureInformation message to the network 110.

[0342] FIG. 10 is an example diagram S400 depicting the method for managing the LTM Cell Switch / Subsequent CPAC execution. As illustrated in FIG. 10, in step S1002, SCG LTM Cell Switch or SCPAC execution is performed. In step S1004, if the SRB3 is configured in the target candidate cell is checked. In step S1005, if the SRB3 is configured in the target candidate cell (condition is yes), then the RRCReconfigurationComplete is sent on SRB3, else in step S1006, the RRCReconfigurationComplete is sent on SRB1.

[0343] The proposed method allows the network entity 110 to modify or release the reference configuration and candidate configuration without affecting the SCPAC execution. The proposed method allows the UE 102 to report the near failure information (Succesful PSCell Change or addition information) during SCPAC execution or legacy PSCellAddition or PSCellChange. The Subsequent CPAC helps the network entity to optimise both internode and Uu signalling, and also helps to reduce the SCG failure by avoiding late configuration ( i.e. avoids too late handovers in the SCG).

[0344] The various actions, acts, blocks, steps, or the like in the flow charts / diagrams (S200-S1000) may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some of the actions, acts, blocks, steps, or the like may be omitted, added, modified, skipped, or the like without departing from the scope of the invention.

[0345] FIG. 11 illustrates various hardware components of a network entity, according to the embodiments as disclosed herein.

[0346] Referring to FIG. 11, the network entity includes a transceiver 1110, a memory 1120, and a processor 1130. The transceiver 1110, the memory 1120, and the processor 1130 of the network entity may operate according to a communication method of the network entity described above. Furthermore, the network entity of FIG. 11 corresponds to the network entity 110 of the FIG. 1C.

[0347] However, the components of the terminal are not limited thereto. For example, the network entity may include fewer or a greater number of components than those described above. However, the components of the network entity are not limited thereto. For example, the network entity may include more or fewer components than those described above. In addition, the processor 1130, the transceiver 1110, and the memory 1120 may be implemented as a single chip. Also, the processor 1130 may include at least one processor.

[0348] The network entity includes at least one entity of a core network. For example, the network entity includes an AMF, a session management function (SMF), a policy control function (PCF), a network repository function (NRF), a user plane function (UPF), a network slicing selection function (NSSF), an authentication server function (AUSF), a UDM and a network exposure function (NEF), but the network entity is not limited thereto.

[0349] The transceiver 1110 collectively refers to a network entity receiver and a network entity transmitter, and may transmit / receive a signal to / from a base station or a UE. The signal transmitted or received to or from the base station or the UE may include control information and data. In this regard, the transceiver 1110 may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for amplifying low-noise and down-converting a frequency of a received signal. However, this is only an example of the transceiver 1110 and components of the transceiver 1110 are not limited to the RF transmitter and the RF receiver.

[0350] The transceiver 1110 may receive and output, to the processor 1130, a signal through a wireless channel, and transmit a signal output from the processor 1130 through the wireless channel.

[0351] The memory 1120 may store a program and data required for operations of the network entity. Also, the memory 1120 may store control information or data included in a signal obtained by the network entity. The memory 1120 may be a storage medium, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0352] The processor 1130 may control a series of processes such that the network entity operates as described above. For example, the transceiver 1110 may receive a data signal including a control signal, and the processor 1130 may determine a result of receiving the data signal.

[0353] FIG. 12 illustrates a structure of a base station according to an embodiment of the disclosure.

[0354] As shown in FIG. 12, the base station according to an embodiment may include a transceiver 1210, a memory 1220, and a processor 1230. The transceiver 1210, the memory 1220, and the processor 1230 of the base station may operate according to a communication method of the base station described above. However, the components of the base station are not limited thereto. For example, the base station may include more or fewer components than those described above. In addition, the processor 1230, the transceiver 1210, and the memory 1220 may be implemented as a single chip. Also, the processor 1230 may include at least one processor.

[0355] The transceiver 1210 collectively refers to a base station receiver and a base station transmitter, and may transmit / receive a signal to / from a terminal (UE) or a network entity. The signal transmitted or received to or from the terminal or a network entity may include control information and data. The transceiver 1210 may include a RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and a RF receiver for amplifying low-noise and down-converting a frequency of a received signal. However, this is only an example of the transceiver 1210 and components of the transceiver 1210 are not limited to the RF transmitter and the RF receiver.

[0356] Also, the transceiver 1210 may receive and output, to the processor 1230, a signal through a wireless channel, and transmit a signal output from the processor 1230 through the wireless channel.

[0357] The memory 1220 may store a program and data required for operations of the base station. Also, the memory 1220 may store control information or data included in a signal obtained by the base station. The memory 1220 may be a storage medium, such as read-only memory (ROM), random access memory (RAM), a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0358] The processor 1230 may control a series of processes such that the base station operates as described above. For example, the transceiver 1210 may receive a data signal including a control signal transmitted by the terminal, and the processor 1230 may determine a result of receiving the control signal and the data signal transmitted by the terminal.

[0359] FIG. 13 illustrates a structure of a UE according to an embodiment of the disclosure.

[0360] As shown in FIG. 13, the UE according to an embodiment may include a transceiver 1310, a memory 1320, and a processor 1330. The transceiver 1310, the memory 1320, and the processor 1330 of the UE may operate according to a communication method of the UE described above. However, the components of the UE are not limited thereto. For example, the UE may include more or fewer components than those described above. In addition, the processor 1330, the transceiver 1310, and the memory 1320 may be implemented as a single chip. Also, the processor 1330 may include at least one processor. Furthermore, the UE of FIG. 13 corresponds to the UE 102 of the FIG. 1B.

[0361] The transceiver 1310 collectively refers to a UE receiver and a UE transmitter, and may transmit / receive a signal to / from a base station or a network entity. The signal transmitted or received to or from the base station or a network entity may include control information and data. The transceiver 1310 may include a RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and a RF receiver for amplifying low-noise and down-converting a frequency of a received signal. However, this is only an example of the transceiver 1310 and components of the transceiver 1310 are not limited to the RF transmitter and the RF receiver.

[0362] Also, the transceiver 1310 may receive and output, to the processor 1330, a signal through a wireless channel, and transmit a signal output from the processor 1330 through the wireless channel.

[0363] The memory 1320 may store a program and data required for operations of the UE. Also, the memory 1320 may store control information or data included in a signal obtained by the UE. The memory 1320 may be a storage medium, such as read-only memory (ROM), random access memory (RAM), a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0364] The processor 1330 may control a series of processes such that the UE operates as described above. For example, the transceiver 1310 may receive a data signal including a control signal transmitted by the base station or the network entity, and the processor 1330 may determine a result of receiving the control signal and the data signal transmitted by the base station or the network entity.

[0365] Those skilled in the art will understand that the various illustrative logical blocks, modules, circuits, and steps described in this application may be implemented as hardware, software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above in the form of their functional sets. Whether such function sets are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Technicians may implement the described functional sets in different ways for each specific application, but such design decisions should not be interpreted as causing a departure from the scope of this application.

[0366] In the above-described embodiments of the disclosure, all operations and messages may be selectively performed or may be omitted. In addition, the operations in each embodiment do not need to be performed sequentially, and the order of operations may vary. Messages do not need to be transmitted in order, and the transmission order of messages may change. Each operation and transfer of each message can be performed independently.

[0367] Although the figures illustrate different examples of user equipment, various changes may be made to the figures. For example, the user equipment can include any number of each component in any suitable arrangement. In general, the figures do not limit the scope of this disclosure to any particular configuration(s). Moreover, while figures illustrate operational environments in which various user equipment features disclosed in this patent document can be used, these features can be used in any other suitable system.

[0368] The various illustrative logic blocks, modules, and circuits described in this application may be implemented or performed by a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic devices, discrete gates or transistor logics, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0369] The steps of the method or algorithm described in this application may be embodied directly in hardware, in a software module executed by a processor, or in a combination thereof. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, register, hard disk, removable disk, or any other form of storage medium known in the art. A storage medium is coupled to a processor to enable the processor to read and write information from / to the storage media. In an alternative, the storage medium may be integrated into the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and the storage medium may reside in the user terminal as discrete components.

[0370] In one or more designs, the functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, each function may be stored as one or more pieces of instructions or codes on a computer-readable medium or delivered through it. The computer-readable medium includes both a computer storage medium and a communication medium, the latter including any medium that facilitates the transfer of computer programs from one place to another. The storage medium may be any available medium that can be accessed by a general purpose or special purpose computer.

[0371] While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.

Claims

1.A method performed by a terminal in a wireless communication system, the method comprising:receiving, from a base station, information for a subsequent conditional primary secondary cell group cell (PSCell) addition or change (CPAC); andidentifying that configuration information applied for an execution of the subsequent CPAC is in accordance with the information for subsequent CPAC.2.The method of claim 1,wherein the configuration information is included in a radio resource control (RRC) reconfiguration message, andwherein the information for the subsequent CPAC includes at least one of first information on a reference configuration for the subsequent CPAC or second information on conditional configuration.3.The method of claim 2, further comprising:generating the configuration information by applying a received subsequent CPAC candidate configuration on the first information; andstoring the configuration information.4.The method of claim 1,wherein, in case that the configuration information is in accordance with the information, the configuration information is applied for the execution of the subsequent CPAC.5.A method performed by a base station in a wireless communication system, the method comprising:transmitting, to a terminal, information for a subsequent conditional primary secondary cell group cell (PSCell) addition or change (CPAC),wherein configuration information applied for an execution of the subsequent CPAC is in accordance with the information for subsequent CPAC.6.The method of claim 5,wherein the configuration information is included in a radio resource control (RRC) reconfiguration message, andwherein the information for the subsequent CPAC includes at least one of first information on a reference configuration for the subsequent CPAC or second information on conditional configuration.7.The method of claim 6,wherein the configuration information is generated based on that a transmitted subsequent CPAC candidate configuration is applied on the first information.8.The method of claim 5,wherein the configuration information in accordance with the information is applied for the execution of the subsequent CPAC.9.A terminal in a wireless communication system, the terminal comprising:a transceiver; andat least one processor coupled with the transceiver and configured to:receive, from a base station, information for a subsequent conditional primary secondary cell group cell (PSCell) addition or change (CPAC), andidentify that configuration information applied for an execution of the subsequent CPAC is in accordance with the information for subsequent CPAC.10.The terminal of claim 9,wherein the configuration information is included in a radio resource control (RRC) reconfiguration message, andwherein the information for the subsequent CPAC includes at least one of first information on a reference configuration for the subsequent CPAC or second information on conditional configuration.11.The terminal of claim 10, wherein the at least one processor is further configured to:generate the configuration information by applying a received subsequent CPAC candidate configuration on the first information, andstore the configuration information.12.The terminal of claim 9,wherein, in case that the configuration information is in accordance with the information, the configuration information is applied for the execution of the subsequent CPAC.13.A base station in a wireless communication system, the base station comprising:a transceiver; andat least one processor coupled with the transceiver and configured to:transmit, to a terminal, information for a subsequent conditional primary secondary cell group cell (PSCell) addition or change (CPAC),wherein configuration information applied for an execution of the subsequent CPAC is in accordance with the information for subsequent CPAC.14.The base station of claim 13,wherein the configuration information is included in a radio resource control (RRC) reconfiguration message, andwherein the information for the subsequent CPAC includes at least one of first information on a reference configuration for the subsequent CPAC or second information on conditional configuration.15.The base station of claim 14,wherein the configuration information is generated based on that a transmitted subsequent CPAC candidate configuration is applied on the first information.

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