Method and apparatus for handling measurements and evaluation of conditional handover in next generation mobile communication systems

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. According to an embodiment of the present disclosure, a method of a user equipment (UE) in a wireless communication system may comprise the steps of: receiving a radio resource control (RRC) reconfiguration message from a base station, the RRC reconfiguration message comprising configuration information for conditional handover (CHO) via a candidate secondary cell group (SCG); when SCG connection failure (SCG failure) occurs in the UE, sending SCG failure information to the base station; and stopping the measurement of the candidate primary and secondary cell (PSCell) when the SCG failure information is transmitted.

Description

Technical Field

[0001] This disclosure relates to techniques for conditional handover of terminal control in mobile communication systems.

[0002] Furthermore, this disclosure relates to a method and apparatus for continuously performing conditional PSCell additions and changes. Background Technology

[0003] 5G mobile communication technology defines a wide frequency band, enabling high transmission rates and new services. It can be implemented not only in the "sub-6 GHz" band, such as 3.5 GHz, but also in the "above 6 GHz" band, including 28 GHz and 39 GHz, known as millimeter wave (mmWave). Furthermore, to achieve transmission rates 50 times faster than 5G and ultra-low latency one-tenth that of 5G, implementation of 6G mobile communication technology (referred to as "super 5G systems") in terahertz bands (e.g., the 95 GHz to 3 THz band) has been considered.

[0004] In the early stages of 5G mobile communication technology development, to support services and meet performance requirements related to enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), standardization has been underway for the following: beamforming and massive MIMO to mitigate radio wave path loss and increase radio wave transmission distance in millimeter waves; support for basic parameter sets (e.g., operating multiple subcarrier spacings) for efficient utilization of millimeter wave resources and dynamic operation of time slot formats; initial access technologies to support multi-beam transmission and broadband; definition and operation of the Bandwidth Part (BWP); new channel coding methods, such as low-density parity-check (LDPC) codes for large-scale data transmission and polar codes for highly reliable transmission of control information; L2 preprocessing; and network slicing to provide dedicated networks for specific services.

[0005] Currently, given the services that 5G mobile communication technology will support, discussions are underway regarding improvements and performance enhancements to the initial 5G mobile communication technology, and physical layer standardization already exists for technologies such as: Vehicle-to-everything (V2X), used to assist autonomous vehicles in determining driving based on information sent by the vehicle about its location and status, and to enhance user convenience; New Radio Unlicensed (NR-U), for system operation in compliance with various regulatory requirements in unlicensed frequency bands; NR UE power saving; Non-Terrestrial Network (NTN), which is UE-satellite direct communication used to provide coverage in areas where communication with terrestrial networks is unavailable; and positioning.

[0006] Furthermore, standardization is underway in air interface architecture / protocols for technologies such as: Industrial Internet of Things (IIoT) to support new services through interoperability and convergence with other industries; Integrated Access and Backhaul (IAB) to provide nodes for network service area extension by supporting radio backhaul and access links in an integrated manner; mobility enhancements, including conditional handover and Dual Active Protocol Stack (DAPS) handover; and two-step random access to simplify random access procedures (2-step RACH for NR). Standardization is also underway in system architecture / services for: 5G baseline architecture (e.g., service-based architecture or service-based interface) to combine Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies; and Mobile Edge Computing (MEC) for receiving services based on UE location.

[0007] With the commercialization of 5G mobile communication systems, the already exponentially growing number of connected devices will connect to the communication network. Accordingly, enhanced functionality and performance of 5G mobile communication systems, as well as the integrated operation of connected devices, are expected to be necessary. To this end, new research is planned related to the following: extended reality (XR) for effectively supporting augmented reality (AR), virtual reality (VR), mixed reality (MR), etc.; improving 5G performance and reducing complexity by leveraging artificial intelligence (AI) and machine learning (ML); AI service support; metaverse service support; and drone communication.

[0008] Furthermore, this development of 5G mobile communication systems will not only serve as the foundation for developing new waveforms for providing terahertz band coverage for 6G mobile communication technologies, multi-antenna transmission technologies (such as full-dimensional MIMO (FD-MIMO), array antennas, and massive MIMO), metamaterial-based lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technologies using orbital angular momentum (OAM), and reconfigurable intelligent surfaces (RIS), but also as the foundation for developing full-duplex technologies to improve the frequency efficiency of 6G mobile communication technologies and improve system networks, AI-based communication technologies to implement system optimization by leveraging satellites and artificial intelligence (AI) from the design stage and internalizing end-to-end AI support capabilities, and next-generation distributed computing technologies to implement services with complexity exceeding the limits of UE operational capabilities by utilizing ultra-high-performance communication and computing resources.

[0009] As stated above, as mobile communication systems evolve to provide a variety of services, a need arises for methods to effectively provide such services. Summary of the Invention

[0010] [Technical Issues]

[0011] This disclosure presents a technique for conditional handover of terminal control in a mobile communication system during a connection failure with a base station.

[0012] Furthermore, this disclosure proposes a method and apparatus for performing subsequent conditional PSCell additions and changes (SCPAC) in a next-generation wireless communication system.

[0013] More specifically, in order to perform SCPAC on the terminal, the conditional and target cell configurations for conditional PSCell addition and modification that need to be applied each time a PSCell changes should be modified. This disclosure proposes a method and apparatus for the network to signal this information to the terminal.

[0014] The technical objectives to be achieved in the embodiments of this disclosure are not limited to those described above, and other technical objectives not mentioned will be clearly understood by those skilled in the art from the following description.

[0015] [Technical Solution]

[0016] A method for a user equipment (UE) in a wireless communication system according to embodiments of the present disclosure may include: receiving a radio resource control (RRC) message from a network node including configuration information for conditional handover of a target primary cell (PCell) and a conditional primary secondary cell (PSCell); sending SCG failure information to the network node when a secondary cell group (SCG) failure occurs; and ceasing conditional evaluation and measurement of candidate PCells and candidate PSCells based on the RRC message.

[0017] A method for a user equipment (UE) in a wireless communication system according to embodiments of the present disclosure may include: receiving a radio resource control (RRC) message from a network node including configuration information for conditional handover of a target primary cell (PCell) and a conditional primary secondary cell (PSCell); sending MCG failure information to the network node when a primary cell group (MCG) failure occurs; and ceasing conditional evaluation and measurement of candidate PCells and candidate PSCells based on the RRC message.

[0018] A user equipment (UE) in a wireless communication system according to embodiments of the present disclosure may include a transceiver and a controller. The controller may receive radio resource control (RRC) messages from a network node, including configuration information for conditional handover of a target primary cell (PCell) and a conditional primary / secondary cell (PSCell), control the transmission of SCG failure information to the network node upon occurrence of a secondary cell group (SCG) failure, and cease conditional evaluation and measurement of candidate PCells and candidate PSCells based on the RRC messages.

[0019] A user equipment (UE) in a wireless communication system according to embodiments of the present disclosure may include a transceiver and a controller. The controller may receive Radio Resource Control (RRC) messages from a network node, including configuration information for conditional handover of the target primary cell (PCell) and conditional primary / secondary cell (PSCell), control the transmission of MCG failure information to the network node upon occurrence of a primary cell group (MCG) failure, and cease conditional evaluation and measurement of candidate PCells and candidate PSCells based on the RRC messages.

[0020] In a method performed by a terminal in a wireless communication system according to an embodiment of the present disclosure, the method includes: receiving a radio resource control (RRC) message from a source base station including subsequent conditional PSCell addition and change (SCPAC) configuration information; changing to a target PSCell that satisfies the PSCell addition and change conditions based on the SCPAC configuration information; and determining, based on the SCPAC configuration information, whether the PSCell addition and change conditions for using the changed target PSCell as the source cell are met.

[0021] [Beneficial Effects]

[0022] Embodiments of this disclosure enable a terminal to effectively control conditional handover even during a connection failure process with a base station in a mobile communication system.

[0023] According to embodiments of this disclosure, a terminal can perform continuous PSCell additions and changes via a single signal to the network.

[0024] The effects of this disclosure are not limited to the foregoing, and other effects not mentioned below will be apparent to those skilled in the art from the following description. Attached Figure Description

[0025] Figure 1 This is a view illustrating the structure of an LTE system according to an embodiment of the present disclosure.

[0026] Figure 2 This is a view illustrating the radio protocol structure of an LTE system according to an embodiment of the present disclosure.

[0027] Figure 3 This is a view illustrating the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0028] Figure 4 This is a view illustrating the structure of a radio protocol for a next-generation mobile communication system according to an embodiment of the present disclosure.

[0029] Figure 5 This is a block diagram illustrating the internal structure of a terminal according to an embodiment of the present disclosure.

[0030] Figure 6 This is a block diagram illustrating the configuration of an NR base station according to an embodiment of the present disclosure.

[0031] Figure 7 The measurement operation of a terminal according to the SCG failure information process is illustrated according to an embodiment of the present disclosure.

[0032] Figure 8 An evaluation operation of a terminal based on an MCG failure information process according to an embodiment of this disclosure is shown.

[0033] Figure 9 This is a view illustrating a subsequent conditional PSCell add and change (SCPAC) configuration method according to an embodiment of this disclosure.

[0034] Figure 10 This is a view illustrating a subsequent conditional PSCell add and change (SCPAC) configuration method according to another embodiment of this disclosure.

[0035] Figure 11 This is a view illustrating a subsequent conditional PSCell add and change (SCPAC) configuration method according to another embodiment of this disclosure.

[0036] Figure 12 This is a view illustrating a subsequent conditional PSCell add and change (SCPAC) configuration method according to another embodiment of this disclosure.

[0037] Figure 13 This is a flowchart illustrating the process of subsequent conditional PSCell Addition and Modification (SCPAC) operations of an execution terminal according to an embodiment of the present disclosure. Detailed Implementation

[0038] The operating principles of this disclosure are described below with reference to the accompanying drawings. Detailed descriptions of known functions or configurations may be omitted when it is determined that the subject matter of the invention is unclear. The terminology used herein is defined in consideration of the functions described in this disclosure and may be replaced with other terms depending on the intent or practice of the user or operator. Therefore, the terminology should be defined based on the entire disclosure.

[0039] As used herein, for ease of description, terms for identifying access nodes, network entities, messages, interfaces between network entities, and various types of identification information are provided as examples. Therefore, this disclosure is not limited to these terms, and these terms may be replaced by other terms representing objects having equivalent technical concepts.

[0040] In the following description, a base station can be an entity that allocates resources to a terminal, and can be at least one of a gNode B, eNode B, Node B, base station (BS), radio access unit, base station controller, or node on a network. A terminal can include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions. In this disclosure, downlink (DL) refers to the radio transmission path of a signal from the base station to the terminal, and uplink (UL) refers to the radio transmission path of a signal from the terminal to the base station. Although LTE or LTE-A systems may be described as examples below, embodiments can be applied to other communication systems with similar technical backgrounds or channel modes. For example, 5G mobile communication technologies (5G, New Radio, NR) developed after LTE-A can be included in systems to which embodiments of this disclosure apply, and 5G below can be a concept including legacy LTE, LTE-A, and other similar services. Furthermore, it will be determined by those skilled in the art that embodiments can be modified without significantly departing from the scope of the invention, and such modifications can be applied to other communication systems. In this context, it should be understood that each block of the process flowchart and combinations of blocks in the flowchart can be executed by computer program instructions.

[0041] Because computer program instructions can be equidistant from a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate means for performing functions associated with each block(s) of a flowchart. Because the computer program instructions can be stored in a computer-usable or computer-readable storage medium that can be oriented toward a computer or other programmable data processing apparatus to implement functions in a specified manner, the instructions stored in the computer-usable or computer-readable storage medium can produce an article including instruction means for performing functions associated with each block(s) of a flowchart. Because the computer program instructions can be equidistant from a computer or other programmable data processing apparatus, the instructions, which, when executed on the computer or other programmable data processing apparatus, generate a series of operational steps that are performed by the computer, and operating the computer or other programmable data processing apparatus can provide steps for performing functions associated with each block(s) of a flowchart.

[0042] Furthermore, each box may represent a module, segment, or portion of code comprising one or more executable instructions for performing the specified logical functions(s). It should also be noted that in some alternative embodiments, the functions mentioned in a box may occur in a different order. For example, depending on the respective function, two consecutively shown boxes may be executed substantially simultaneously or in reverse order. As used herein, the term “unit” refers to a software element or hardware element, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC). A unit may serve a specific function. However, a “unit” is not limited to software or hardware. A “unit” may be configured in a storage medium that can be addressed or configured to execute one or more processors. Thus, by way of example, a “unit” includes elements (such as software elements, object-oriented software elements, class elements, and task elements), processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data schemas, tables, arrays, and variables. The functionality provided within components and “units” may be combined into a smaller number of components and “units,” or further divided into additional components and “units.” Furthermore, the component and "unit" can be implemented as one or more CPUs in an execution device or secure multimedia card. According to an embodiment, "...unit" may include one or more processors.

[0043] For ease of description, this document uses the terms and names defined in the 3GPP 5G and NR standards of current communication standards. However, this disclosure is not limited to these terms and names and can be equally applied to wireless communication networks conforming to other standards. For example, this disclosure can be applied to 3GPP GS / NR (the fifth-generation mobile communication standard).

[0044] Figure 1 This is a view illustrating the structure of an LTE system according to an embodiment of the present disclosure.

[0045] refer to Figure 1 As shown in the figure, the radio access network of an LTE system may include next-generation base stations (Evolved Node B - hereinafter, ENB, Node B, or base station) 105, 110, 115, and 120, a Mobility Management Entity (MME) 125, and a Service Gateway (S-GW) 130. User equipment (hereinafter, "UE" or "terminal") 135 can access external networks through ENBs 105 to 120 and S-GW 130.

[0046] Figure 1ENBs 105 to 120 can correspond to Node Bs in a traditional Universal Mobile Telecommunications System (UMTS) system. The ENB connects to the UE 135 via radio channels and plays a more complex role than a traditional Node B. In LTE systems, all user services, including real-time services such as Voice over IP (VoIP) via the Internet Protocol, can be served through shared channels. Therefore, equipment is needed to perform scheduling by collecting state information such as the UE's buffer state, available transmission power state, and channel state, and ENBs 105 to 120 can play this role. A single ENB can typically control multiple cells. For example, an LTE system can use Orthogonal Frequency Division Multiplexing (OFDM) as the radio access technology on a 20MHz bandwidth to achieve a transmission speed of 100Mbps. Furthermore, the system can apply Adaptive Modulation and Coding (AMC), which determines the modulation scheme and channel coding rate based on the terminal's channel state. The S-GW 130 is the device that provides data bearers and can generate or remove data bearers under the control of the MME 125. MME 125 is a device responsible for various control functions and mobility management functions of terminal 135, and can be connected to multiple base stations.

[0047] Figure 2 This is a view illustrating the structure of the radio protocol of an LTE system according to an embodiment of the present disclosure.

[0048] refer to Figure 2 The radio protocols of the LTE system may include Packet Data Convergence Protocol (PDCP) 05, 240, Radio Link Control (RLC) 10, 235 and Media Access Control (MAC) 215, 230 in the terminal and ENB respectively.

[0049] PDCP 205 and 240 can be responsible for IP header compression / reconstruction. The main functions of PDCP can be summarized as follows.

[0050] -Header compression and decompression: ROHC only)

[0051] -Transmission of user data

[0052] - Deliver upper-layer PDUs sequentially during the PDCP reconstruction process of RLC AM

[0053] - For split bearers in the DC (RLC AM only), PDCP PDU routing for transmission and PDCP PDU reordering for reception.

[0054] - Repeatedly detect the lower-layer SDU during the PDCP reconstruction process of RLC AM

[0055] - Retransmit PDCP SDUs during handover, and for segmented bearers in the DC, retransmit PDCP PDUs during PDCP data recovery for RLC AM.

[0056] - Encryption and decryption

[0057] -Timer-based SDU dropping in the uplink

[0058] Radio Link Control (RLC) 210 and 235 can reconfigure PDCP Packet Data Units (PDUs) to an appropriate size and perform ARQ operations. The main functions of RLC 210 and 235 can be summarized as follows.

[0059] -Transmission of upper-layer PDUs

[0060] - Error correction via ARQ (for AM data transmission only)

[0061] - Cascading, segmenting, and reassembling of RLC SDUs (for UM and AM data transmission only)

[0062] - Resegmentation of RLC data PDUs (for AM data transmission only)

[0063] - Reordering of RLC data PDUs (for UM and AM data transfer only)

[0064] - Duplicate detection (only for UM and AM data transmission)

[0065] - Protocol error detection (for AM data transmission only)

[0066] -RLC SDU discard (only for UM and AM data transfer)

[0067] -RLC Reconstruction

[0068] MAC 215 and 230 can connect to several RLC layer devices configured in a single terminal, and can multiplex RLC PDUs into MAC PDUs and demultiplex RLC PDUs from MAC PDUs. The main functions of MAC 215 and 230 can be summarized as follows.

[0069] Mapping between logical channels and transport channels

[0070] - Multiplexing MAC SDUs belonging to one or different logical channels into / from a transport block (TB) delivered to / from the physical layer on the transport channel / demultiplexing MAC SDUs belonging to one or different logical channels from / from a transport block (TB) delivered to / from the physical layer on the transport channel.

[0071] - Scheduling Information Report

[0072] - Error correction via HARQ

[0073] Priority processing between logical channels of a UE

[0074] - Prioritization among UEs is performed through dynamic scheduling.

[0075] -MBMS service identifier

[0076] -Transmission format selection

[0077] -filling

[0078] Physical layers 220 and 225 can encode and modulate higher-layer data channels into OFDM symbols, transmit OFDM symbols through radio channels, or demodulate OFDM symbols received through radio channels, decode the channels, and transmit them to higher layers.

[0079] Figure 3 This is a view illustrating the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0080] refer to Figure 3 The radio access network for next-generation mobile communication systems (hereinafter referred to as NR or 5G) may include a next-generation base station (new radio node B, hereinafter referred to as NR gNB or NR base station) 310 and a next-generation radio core network (NRCN) 305. Next-generation radio user equipment (hereinafter, NR UE or terminal) 315 can access external networks through NR gNB 310 and NR CN 305.

[0081] exist Figure 3 In this context, the NR gNB 310 can correspond to an evolved Node B (eNB) in an LTE system. The NR gNB connects to the NR UE 315 via a radio channel and can provide superior service compared to a traditional Node B. In next-generation mobile communication systems, all user services can be served through a shared channel. Therefore, there is a need for equipment to perform scheduling by collecting state information such as the UE's buffer state, available transmission power state, and channel state, and the NR gNB 310 can be responsible for scheduling.

[0082] A single NR gNB 310 can typically control multiple cells. In next-generation mobile communication systems, bandwidths exceeding the conventional maximum bandwidth can be applied to achieve ultra-high-speed data transmission over traditional LTE. Furthermore, orthogonal frequency division multiplexing (OFDM) can be used as a radio access technology to additionally apply beamforming techniques. Additionally, adaptive modulation and coding (AMC) can be applied to determine the modulation scheme and channel coding rate based on the channel state of the terminal 315.

[0083] The NR CN 305 can perform functions such as mobility support, bearer configuration, and QoS configuration. The NR CN 305 is responsible for various control functions and mobility management functions of terminal 315, and can connect to multiple base stations. Furthermore, next-generation mobile communication systems can link with LTE systems. The NR CN 305 can connect to the MME 325 via a network interface. The MME 325 can connect to the eNB 330, which acts as an LTE base station.

[0084] Figure 4 This is a view illustrating the structure of a radio protocol for a next-generation mobile communication system according to an embodiment of the present disclosure.

[0085] refer to Figure 4 The radio protocol of the next-generation mobile communication system can be composed of NR Service Data Adaptation Protocol (SDAP) 401, 445, NR PDCP 405, 440, NR RLC 410, 435, NR MAC 415, 430 and NR PHY 420, 425 in the terminal and NR base station respectively.

[0086] The main functions of NR SDAP 401 and 445 may include some or all of the following functions.

[0087] -Transmission of user plane data

[0088] - Mapping between QoS flows and DRB for both DL and UL

[0089] - Mark QoS flow IDs in DL and UL groups

[0090] - Reflection QoS flow to DRB mapping for UL SDAP PDU

[0091] For SDAP layer devices, Radio Resource Control (RRC) messages can be used to configure whether the terminal uses the SDAP layer entity header or SDAP layer entity functionality for each PDCP layer entity, each bearer, or each logical channel. When configuring the SDAP header, the terminal can indicate this via a 1-bit Non-Access Stratum (NAS) Quality of Service (QoS) reflection configuration indicator (NAS reflected QoS) and an 1-bit Access Stratum (AS) QoS reflection configuration indicator (AS reflected QoS) in the SDAP header, allowing the terminal to update or reconfigure the mapping information regarding uplink and downlink data bearers and QoS flows. The SDAP header can include QoS flow ID information indicating QoS. QoS information can be used as data prioritization or scheduling information to seamlessly support service.

[0092] The main functions of NR PDCP 405 and 440 may include all or some of the following functions.

[0093] -Header compression and decompression: ROHC only)

[0094] -Transmission of user data

[0095] - Sequential delivery of upper-layer PDUs

[0096] -Disordered delivery of upper-layer PDUs

[0097] - Reordering of received PDCP PDUs

[0098] -Duplicate detection of lower-level SDUs

[0099] -PDCP SDU retransmission

[0100] - Encryption and decryption

[0101] -Timer-based SDU dropping in the uplink

[0102] In the above description, the reordering function of an NR PDCP device can refer to the function of reordering PDCP PDUs received from lower layers in sequence based on the PDCP sequence number (SN). Reordering by an NR PDCP device may include transmitting data to higher layers in the reordered order or immediately regardless of the order, recording lost PDCP PDUs through reordering, reporting the status of lost PDCP PDUs to the transmitting part, and requesting retransmission of lost PDCP PDUs.

[0103] The main functions of NR RLC 410 and 435 may include all or some of the following functions.

[0104] -Transmission of upper-layer PDUs

[0105] - Sequential delivery of upper-layer PDUs

[0106] -Disordered delivery of upper-layer PDUs

[0107] -Error correction via ARQ

[0108] Cascading, segmentation, and reassembly of RLC SDUs

[0109] - Resegmentation of RLC data PDUs

[0110] - RLC data PDU reordering

[0111] -Duplicate detection

[0112] -Protocol error detection

[0113] -RLC SDU discard

[0114] -RLC Reconstruction

[0115] In this context, the sequential delivery function of an NR RLC device can refer to the function of sequentially delivering RLCSDUs received from a lower layer to an upper layer. When receiving a raw RLC SDU that has been divided into multiple RLC SDUs, the sequential delivery function of an NR RLC device can include the function of reassembling and delivering them.

[0116] The sequential delivery function of the NR RLC device may include the function of reordering received RLC PDUs based on the RLC sequence number (SN) or PDCP sequence number (SN), the function of recording lost RLC PDUs by reordering the sequence, the function of reporting the status of lost RLC PDUs to the sending side, and the function of requesting retransmission of lost RLC PDUs.

[0117] The sequential delivery function of NR RLC devices may include the ability to sequentially deliver only the RLC SDUs preceding the lost RLC SDU to the upper layer when a lost RLC SDU exists.

[0118] The sequential delivery function of NR RLC devices can include the following function: even when there are lost RLC SDUs, if a scheduled timer expires, all RLC SDUs received before the timer starts will be delivered to the upper layer in sequence.

[0119] The sequential delivery function of the NR RLC device can include the following function: even when there are lost RLC SDUs, if a predetermined timer expires, all RLC SDUs received so far will be delivered to the upper layer in sequence.

[0120] NR RLC devices can process RLC PDUs in the order they are received, regardless of the sequence number (out-of-order delivery), and deliver them to NR PDCP devices.

[0121] When an NR RLC device receives a segment, it can receive segments stored in a buffer or to be received later, reconstruct them into a complete RLC PDU, and then deliver it to an NR PDCP device.

[0122] The NR RLC layer may not include cascading functionality, and it can be implemented in the NR MAC layer or replaced by multiplexed functionality of the NR MAC layer.

[0123] In this context, the out-of-order delivery function of an NR RLC device can refer to the function of immediately delivering RLC SDUs received from lower layers to upper layers regardless of their order. The out-of-order delivery function of an NR RLC device can include the function of reassembling and delivering a single original RLC SDU that has been divided into multiple RLC SDUs upon receipt. The out-of-order delivery function of an NR RLC device can also include the function of storing the RLC SN or PDCP SN of received RLC PDUs and recording lost RLC PDUs by reordering them.

[0124] NR MAC 415, 430 can connect to multiple NR RLC layer devices configured in a single terminal, and the main functions of NR MAC 415, 430 may include some or all of the following functions.

[0125] Mapping between logical channels and transport channels

[0126] - MAC SDU multiplexing / demultiplexing

[0127] - Scheduling Information Report

[0128] - Error correction via HARQ

[0129] Priority processing between logical channels of a UE

[0130] - Prioritization among UEs is performed through dynamic scheduling.

[0131] -MBMS service identifier

[0132] -Transmission format selection

[0133] -filling

[0134] NR PHY layers 420 and 425 can encode and modulate higher-layer data channels into OFDM symbols, transmit OFDM symbols via radio channels, or demodulate OFDM symbols received via radio channels, decode the channels, and transmit them to higher layers.

[0135] Figure 5 This is a block diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0136] refer to Figure 5 The terminal includes a radio frequency (RF) processor 510, a baseband processor 520, a storage unit 530, and a controller 540.

[0137] RF processor 510 performs functions for transmitting and receiving signals via a radio channel, such as frequency band conversion and signal amplification. RF processor 510 up-converts baseband signals provided by baseband processor 520 into RF band signals and transmits them via an antenna, and down-converts RF band signals received via the antenna back into baseband signals. For example, RF processor 510 may include transmit filters, receive filters, amplifiers, mixers, oscillators, digital-to-analog converters (DACs), analog-to-digital converters (ADCs), etc. Figure 5 For ease of description, only one antenna is shown, but the terminal may have multiple antennas. The RF processor 510 may include multiple RF chains. Furthermore, the RF processor 510 can perform beamforming. For beamforming, the RF processor 510 can adjust the phase and amplitude of each signal transmitted / received through multiple antennas or antenna elements. Additionally, the RF processing unit can perform MIMO and receive several layers when performing MIMO operation.

[0138] The baseband processor 520 performs the conversion function between baseband signals and bitstreams according to the system physical layer specifications. For example, when transmitting data, the baseband processor 520 can generate complex symbols by encoding and modulating the transmitted bit string. Furthermore, when receiving data, the baseband processor 520 can recover the received bit string by demodulating and decoding the baseband signal provided from the RF processor 510. For example, according to the Orthogonal Frequency Division Multiplexing (OFDM) method, when transmitting data, the baseband processor 520 generates complex symbols by encoding and modulating the transmitted bit string, maps the complex symbols to subcarriers, and constructs OFDM symbols through inverse Fast Fourier Transform (IFFT) operations and cyclic prefix (CP) insertion. Furthermore, when receiving data, the baseband processor 520 divides the baseband signal provided from the RF processor 510 into OFDM symbol units, recovers the signal mapped to the subcarriers through Fast Fourier Transform (FFT), and recovers the received bit string through demodulation and decoding.

[0139] Baseband processor 520 and RF processor 510 may transmit and / or receive signals according to embodiments of this disclosure. Baseband processor 520 and RF processor 510 may be referred to as a transmitter, receiver, transceiver, communication unit, or transceiver. At least one of baseband processor 520 and RF processor 510 may include multiple communication modules to support a variety of different radio access technologies. Furthermore, at least one of baseband processor 520 and RF processor 510 may include different communication modules for processing signals in different frequency bands. For example, different radio access technologies may include, for example, wireless LAN (e.g., IEEE 802.11) or cellular networks (e.g., LTE). Additionally, different frequency bands may include ultra-high frequency (SHF) bands (e.g., 2.0 NRHz or NRHz) bands or millimeter wave (mmWave) bands (e.g., 60 GHz) bands.

[0140] Storage unit 530 stores basic programs, application programs, configuration information, or other data used to operate the terminal. Specifically, storage unit 530 may store information related to a second access node performing wireless communication using a second radio access technology. Furthermore, storage unit 530 provides stored data upon request from controller 540.

[0141] Controller 540 controls the overall operation of the terminal. For example, controller 540 sends and receives signals via baseband processor 520 and RF processor 510. Furthermore, controller 540 records data in / reads data from storage unit 540. For this purpose, controller 540 may include at least one processor. For example, controller 540 may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as applications.

[0142] Figure 6 This is a block diagram illustrating the configuration of an NR base station according to an embodiment of the present disclosure.

[0143] refer to Figure 6 The base station can be configured to include an RF processor 610, a baseband processor 620, a backhaul communication unit 630, a storage unit 640, and a controller 650.

[0144] RF processor 610 performs functions for transmitting and receiving signals over a radio channel, such as frequency band conversion and signal amplification. RF processor 610 up-converts baseband signals provided by baseband processor 620 to RF band signals and transmits them via an antenna, and down-converts RF band signals received via the antenna back to baseband signals. For example, RF processor 610 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, and ADCs. Figure 6For ease of description, only one antenna is shown in the diagram, but a base station can have multiple antennas.

[0145] RF processor 610 may include multiple RF chains. Furthermore, RF processor 610 can perform beamforming. For beamforming, RF processor 610 can adjust the phase and amplitude of each signal transmitted / received through multiple antennas or antenna elements. RF processor 610 can perform down-MIMO operation by transmitting one or more layers.

[0146] The baseband processor 620 can perform the conversion function between baseband signals and bit strings according to the physical layer specification of the first radio access technology. For example, when transmitting data, the baseband processor 620 can generate complex symbols by encoding and modulating the transmitted bit string. Furthermore, when receiving data, the baseband processor 620 can recover the received bit string by demodulating and decoding the baseband signal provided from the RF processor 610. For example, according to the OFDM method, when transmitting data, the baseband processor 620 generates complex symbols by encoding and modulating the transmitted bit string, maps the complex symbols to subcarriers, and constructs OFDM symbols through IFFT operations and CP insertion. Furthermore, when receiving data, the baseband processor 620 divides the baseband signal provided from the RF processor 610 into OFDM symbol units, recovers the signal mapped to the subcarriers through FFT operations, and recovers the received bit string through demodulation and decoding. The baseband processor 620 and the RF processor 610 can transmit and / or receive signals according to embodiments of this disclosure. The baseband processor 620 and the RF processor 610 may be referred to as a transmitter, receiver, transceiver, communication unit, wireless communication unit, or transceiver.

[0147] The backhaul communication unit 630 can provide an interface for communicating with other nodes in the network. The backhaul communication unit 630 can convert bit strings sent from the primary base station to other nodes (e.g., secondary base stations, core network, etc.) into physical signals, and can convert physical signals received from other nodes into bit strings.

[0148] Storage unit 640 can store data such as basic programs, application programs, and configuration information for the operation of the main base station. Specifically, storage unit 640 can store, for example, information about bearers assigned to connected terminals and measurement results reported from connected terminals. Further, storage unit 640 can store information used as a reference for determining whether to provide multiple connections to terminals or to terminate them. Storage unit 640 can provide the stored data upon request from controller 650.

[0149] The controller 650 can control the overall operation of the base station. For example, the controller 650 can transmit / receive signals via the baseband processor 620 and RF processor 610 or via the backhaul communication unit 6-30. Furthermore, the controller 650 can write or read data from the storage unit 640. The controller 650 may include at least one processor.

[0150] At the same time, Figure 7 and Figure 8 The following abbreviations may be used in Chinese.

[0151] S-MN: Source Master Node

[0152] T-MN: Target Master Node

[0153] S-Pcell: Source cell

[0154] T-Pcell: Target Primary Cell

[0155] S-SN: Source and Secondary Nodes

[0156] T-SN: Target Auxiliary Node

[0157] S-PScell: Source PScell

[0158] T-PScell: Target PScell

[0159] DC: Dual Connection

[0160] CHO: Conditional transfer

[0161] Utilizing the CHO of the candidate SCG: UE function / features regarding the simultaneous execution of conditional handover to the target Pcell and conditional PScell ​​change to the target PScell.

[0162] MO: Measurement Object

[0163] MCG: Main Cell Group

[0164] SCG: Auxiliary Community Group

[0165] Figure 7 The measurement operation of a terminal according to the SCG failure information process is illustrated according to an embodiment of the present disclosure.

[0166] refer to Figure 7 In operation 701, the S-MN and T-MN can prepare a CHO for utilizing the candidate SCG. In operation 703, the UE can receive an RRCReconfiguration message from the S-MN that includes the CHO configuration for utilizing the candidate SCG prepared in operation 701.

[0167] According to an embodiment, the CHO configuration using candidate SCG received by the terminal (or UE) from the network (or node) may include at least one of the following information.

[0168] - A list of candidate target PCell configurations and candidate target PSCell configuration pairs.

[0169] - A list of condition pairs for the target PCell and the target PSCell.

[0170] - Conditional ID reconfiguration

[0171] According to an embodiment, each conditional reconfiguration ID can be associated with a {candidate target PCell configuration and candidate target PSCell configuration pair} and {conditional information associated with the candidate target PCell and conditional information associated with the candidate target PSCell pair}.

[0172] According to an embodiment, the condition information may be conditions related to the corresponding candidate target PCell and the corresponding candidate target PSCell associated with the conditional reconfiguration ID. When both the PCell-related conditions and the PSCell-related conditions are met simultaneously, the terminal can perform a CHO operation using the candidate SCG. The CHO operation using the candidate SCG may be an operation that applies the candidate target PCell configuration and the candidate target PSCell configuration associated with the conditional reconfiguration ID. According to an embodiment, the candidate target PCell configuration and the candidate target PSCell configuration may be included in the same single RRCReconfiguration message.

[0173] According to the implementation method, the condition of each PCell or PSCell may refer to the measurement ID (measurement ID or measID) configured in the PCell or PSCell, and multiple measurement IDs can constitute the condition of a PCell or PSCell at the same time.

[0174] In operation 705, the UE can perform a measurement on the candidate target PCell, and in operation 707, the UE can perform a measurement on the candidate target PSCell. Operations 705 and 707 correspond to the MO measurement performed by the terminal in operation 709, and based on this measurement, the terminal can begin condition evaluation.

[0175] In operation 711, an SCG failure may occur between the UE and the S-SN. According to an embodiment, the conditions under which an SCG failure occurs may be at least one of the following: radio link failure (RLF) in the SCG connection, reconfigurationwithSync failure, reconfiguration failure, beam failure of the PSCell when the SCG is deactivated, and an integrity check failure indication from the lower layer of the SCG regarding SRB3.

[0176] When the terminal is a dual-connected PCell with S-MN and PSCell with S-SN, it can receive CHO configurations using candidate SCGs from the network and perform measurement and condition evaluation operations on the relevant candidate target PCells and PSCells.

[0177] According to an embodiment, the measurement corresponding to the candidate target PCell and PSCell can be the measurement object indicated by each condition, and while performing the measurement, an evaluation of specific events related to the report configuration associated with the measurement object and condition information can be performed simultaneously.

[0178] During operation, SCG failure may occur in specific SCG-related operations, and when an SCG failure occurs, in operation 713, the UE can send SCG failure information to the S-MN. According to an embodiment, the UE can include failure-related information in the SCG failure information message and deliver it to the network (or S-MN) using the MCG link.

[0179] In operation 715, the UE may not perform a measurement on the candidate target PCell, and in operation 717, the UE may not perform a measurement on the candidate target PSCell.

[0180] When the UE sends an SCG failure information message to the MN, if a CHO utilizing a candidate SCG is configured, then in operation 719, the UE may perform at least one of the following operations.

[0181] - The evaluation operation corresponding to the conditions of each candidate target PCell and PSCell in the CHO configuration utilizing candidate SCG can be stopped.

[0182] - It can stop the measurement operation being performed for the condition evaluation corresponding to each candidate target PCell and PSCell in the CHO configuration utilizing candidate SCG.

[0183] The measurement operation can be a measurement operation of the MO associated with a measurement ID, which is indicated as condition information corresponding to each candidate target PCell and PSCell configured using the CHO of the candidate SCG.

[0184] The reason for stopping the measurement is that, since a failure report has already been sent to the network through the SCG failure information process, we should wait for a separate instruction from the network. Therefore, the UE itself should not perform operations on the mobile PCell and PSCell, i.e., perform operations using the CHO of the candidate SCG.

[0185] According to the embodiments, the following operations can be considered for measuring the stop operation.

[0186] When a measurement operation is stopped, the stop of measurement of the current PSCell can be excluded from the measurement stop operation if the current PSCell at the time of the SCG failure information operation is configured as a candidate target PSCell in the CHO configuration of the candidate SCG.

[0187] The reason is that even when executing the SCG failure information process, the terminal needs to maintain the measurement configuration associated with its current PSCell, perform measurement operations, record measurement results when necessary, and keep the latest results for later use in the SON / MDT failure report.

[0188] As an exception, when a measurement operation is stopped, if the terminal is currently (i.e., when executing the SCG failure information procedure) configured to perform a candidate target PCell for a general CHO and the resulting measurement and evaluation, then the measurement of the candidate target PCell for that CHO can be excluded from the target of the measurement stop operation based on the CHO configuration utilizing the candidate SCG. In other words, if the candidate target PCell for a CHO utilizing the candidate SCG is included, the measurement of that included candidate target PCell is not stopped.

[0189] The reason is that CHOs and CHOs utilizing candidate SCGs can be configured independently for the target cell. Therefore, in the case of a candidate target PCell, the same PCell can be configured, and the network should in many cases also configure a CHO for that PCell to prevent PCell status deterioration without triggering a CHO utilizing the candidate SCG. In this case, if PCell measurement stops due to SCG failure, the CHO for that candidate target PCell also stops. Therefore, the terminal should selectively avoid stopping PCell measurement in this situation.

[0190] In another embodiment, in the event that selective PCell measurement is stopped, even when the same PCell is indicated for measurement in both the CHO and the CHO utilizing the candidate SCG, the terminal can stop measuring the candidate target PCell on the CHO utilizing the candidate SCG if the specific parameters of the MO indicating the PCell are different, i.e., if indicated by different MOs. Measurements of the candidate target PCell on the CHO can still be performed. Since the measurement is performed against the MO, if the MOs are different, i.e., if different factors are configured within the MOs, the measurements can be considered separate.

[0191] After the measurement operation is stopped, in operation 721, the UE can receive an RRCReconfiguration message from the S-MN that includes new configuration information. According to an embodiment, the configuration information may include the addition of a new SCG, i.e., the configuration of a new PSCell. According to an embodiment, the configuration information may include measurement configuration information in the corresponding PSCell. According to an embodiment, the configuration information may include the configuration of a new CHO utilizing a candidate SCG. The UE that has received the new configuration information can perform the measurement operation according to the configuration. When performing the measurement, it may or may not indicate the measurement of the existing PSCell again.

[0192] Figure 8 The present disclosure illustrates a CHO evaluation operation of a terminal using candidate SCGs based on an MCG failure information process according to an embodiment of the present disclosure.

[0193] Reference Figure 8 Operations 801 to 809 are respectively related to Figure 7 Operations 701 to 709 are basically the same, so their descriptions are omitted.

[0194] In operation 811, an MCG failure may occur between the UE and the network (or S-MN). According to an embodiment, an MCG failure occurs when a radio link failure occurs in the MCG connection. More specifically, an MCG failure may occur under the following conditions.

[0195] The process of a UE configured to separate SRB1 or SRB3 initiating a report of MCG failure.

[0196] -When neither MCG nor SCG transmission is paused

[0197] -When SCG is not deactivated

[0198] - When t316 is configured, and when the following conditions are met:

[0199] 1> When a radio link failure of the MCG is detected, and the T316 is not running at the same time,

[0200] When the UE is dual-connected with a PCell configured with an S-MN and a PSCell configured with an S-SN, it can receive CHO configurations using candidate SCGs from the network and perform measurement and condition evaluation operations on the relevant candidate target PCells and PSCells.

[0201] According to an embodiment, the measurement corresponding to the candidate target PCell and PSCell can be the measurement object indicated by each condition, and while performing the measurement, an evaluation of specific events related to the report configuration associated with the measurement object and condition information can be performed simultaneously.

[0202] MCG failures may occur during specific MCG-related operations, and when an MCG failure occurs, the UE can send MCG failure information to the network (or S-SN) in operation 813, according to the conditions mentioned above. According to an embodiment, the UE can include failure-related information in the MCG failure information message and deliver it to the network (or S-SN) using the SCG link.

[0203] In operation 815, the UE may not perform a measurement on the candidate target PCell, and in operation 817, the UE may not perform a measurement on the candidate target PSCell.

[0204] According to an embodiment, when the UE sends an MCG failure information message by separating SRB1 or SRB3, if a CHO utilizing a candidate SCG is configured, then in operation 819, the UE may perform at least one of the following operations.

[0205] - The evaluation operation corresponding to the conditions of each candidate target PCell and PSCell in the CHO configuration utilizing candidate SCG can be stopped.

[0206] - It can stop the measurement operation being performed for the condition evaluation corresponding to each candidate target PCell and PSCell in the CHO configuration utilizing candidate SCG.

[0207] The measurement operation can be a measurement operation of the MO associated with a measurement ID, which is indicated as condition information corresponding to each candidate target PCell and PSCell configured using the CHO of the candidate SCG.

[0208] The reason for stopping the condition evaluation is that since the UE has already notified the network of the MCG issue, it should wait for additional commands or configurations from the network. If the UE moves to another PCell on its own, the network will not only be unaware of the terminal's location, but may also be unable to configure the necessary commands in a timely manner. Therefore, the UE should stop its own movement.

[0209] In operation 821, after stopping the measurement operation and / or condition evaluation, the UE can receive an RRCReconfiguration message from the S-SN including new configuration information. According to an embodiment, the configuration information may include configuration related to moving to a specific PCell. According to an embodiment, the configuration information may include measurement configuration information in the corresponding PCell. According to an embodiment, the configuration information may include a configuration utilizing a new CHO (Candidate HCG). The UE that has received this new configuration information can perform a measurement operation according to the configuration. This execution may or may not include measurements of existing PCells that are re-indicated.

[0210] The following abbreviations may be used in this disclosure.

[0211] MN: Master Node

[0212] SN: Secondary node

[0213] CPAC: Conditional PSCell Addition and Modification refers to the ability of a terminal to add or move to a PSCell when specific conditions are met.

[0214] SCPAC: Continuous CPAC refers to the function of continuously performing CPAC operations even after the terminal has moved to a specific PSCell without requiring separate network configuration operations.

[0215] MO: Measurement Object

[0216] Figure 9 This is a view illustrating a subsequent conditional PSCell add and change (SCPAC) configuration method according to an embodiment of this disclosure.

[0217] More specifically, Figure 9 It is a view that shows the information and terminal operations included in each field when generating (creating) subsequent conditional PSCell add and change (SCPAC) configurations as incremental (delta) configurations.

[0218] The terminal can receive an RRC reconfiguration message (or RRCReconfiguration message) from the base station. The RRCReconfiguration message may include fields containing configuration information related to conditional mobility (e.g., a conditional reconfiguration field). More specifically, the RRCReconfiguration message may contain fields for collecting and delivering conditional mobility-related configurations, which may be referred to as, for example, conditional reconfiguration.

[0219] The conditional reconfiguration field can include conditional information to be considered when moving from the current PSCell, which is the source cell, to a candidate target PSCell, as well as the target cell configuration (or configuration information) to be used when moving to the corresponding cell. This information can be in the form of a list of entries associated with the condReconfig ID.

[0220] More specifically, the conditional reconfiguration field may include at least one or more entries associated with a condReconfig ID (hereinafter referred to as "conditional candidate PSCell change configuration entries"). Each entry may include a condReconfig ID, at least one or more conditional information to be considered when moving from the current PSCell, which is the source cell, to a candidate target PSCell, and configuration information of the target PSCell used when moving to a specific candidate target PSCell. Additionally, the conditional reconfiguration field may also include an SCPAC reference config.

[0221] For example, such as Figure 9 As shown, when the current PSCell is PSCell 5, the conditional reconfiguration field can include a list of entries associated with the condReconfig ID, and each entry associated with the condReconfig ID (or "conditional candidate PSCell change configuration entry") can be as follows.

[0222] (1) The entry associated with condReconfig ID1 may include condReconfig ID1, cond1 (information to be considered when moving from PSCell5, the source cell, to PSCell1, the target PSCell) and PSCell 1config (configuration information of the target PSCell).

[0223] (2) The entry associated with condReconfig ID2 may include condReconfig ID2, cond2 (information to be considered when moving from PSCell5, the source cell, to PSCell2, the target PSCell) and PSCell 2config (configuration information of the target PSCell).

[0224] (3) The entry associated with condReconfig ID3 may include condReconfig ID3, cond3 (information to be considered when moving from PSCell5, the source cell, to PSCell3, the target PSCell), and PSCell 3config (configuration information for the target PSCell).

[0225] (4) The entry associated with condReconfig ID4 may include condReconfig ID4, cond4 (information to be considered when moving from PSCell5, which is the source cell, to PSCell4, which is the target PSCell), and PSCell4Config (configuration information of the target PSCell).

[0226] An SCPAC configuration (or SCPAC config) can be added for each conditional candidate PSCell configuration change entry. When the SCPAC configuration (or SCPAC config) is indicated, the terminal can perform additional SCPAC, i.e., subsequent SCPAC operations when moving (or changing) to the candidate target PSCell of the corresponding entry, and the SCPAC configuration (or SCPAC config) can include the information necessary for such SCPAC operations.

[0227] The information necessary for SCPAC operation may include any one or more of the following.

[0228] -SCPAC config ID

[0229] ID is an integer value.

[0230] Assign an ID value to a source PSCell corresponding to a specific PSCell, based on the source PSCell indication information below.

[0231] - Apply SCPAC configuration to the source PSCell instruction information

[0232] The PSCell instruction information can be one of the following.

[0233] In the conditional reconfiguration field containing SCPAC configuration, the specific condReconfig ID

[0234] In this context, it refers to the PSCell as an eight-bit byte string indicated by the Physical Cell Identifier (PCI) and Absolute Radio Channel Number (ARFCN) in RRCReconfiguration, i.e., the target PSCell configuration information indicated by the condReconfig ID.

[0235] A combination of PCI and ARFCN information indicating a specific PSCell

[0236] RRCReconfiguration message as a specific octet string

[0237] In this case, it contains a reconfigurationWithSync field inside the message and refers to the PSCell indicated by the PCI and ARFCN in that field.

[0238] If no explicit source PSCell information is available, the terminal will treat the target PSCell in the entry containing the conditional reconfiguration of the corresponding SCPAC config as the source PSCell. This information can be used when stored in long-term variables.

[0239] - A list of {conditional reconfiguration IDs, conditions for candidate target PSCells, and configurations for candidate target PSCells}

[0240] Conditional ID reconfiguration: The ID in the list of entries is used to refer to each entry.

[0241] Candidate Target PSCell Configuration: Target cell configuration information used when moving from the source PSCell associated with this SCPAC configuration to a specific target PSCell. This can be an octet of an RRCReconfiguration message. The terminal can identify the corresponding target PSCell by the PCI and ARFCN present in the reconfigurationWithSync field of this message. This configuration information is an incremental configuration used in conjunction with the SCPAC reference configuration. The combined configuration becomes the final configuration of the target PSCell.

[0242] Candidate target PSCell conditions: Information on the conditions that must be met when moving from the source PSCell associated with this SCPAC config to the corresponding candidate target PSCell. It can be indicated by the measId in the measurement config configured for the current PSCell (i.e., the source PSCell associated with this SCPAC config), and when multiple measIds are indicated, the conditions can be considered met when all events corresponding to each measId are satisfied.

[0243] For example, such as Figure 9 As shown, the entry associated with condReconfig ID3 and the entry associated with condReconfig ID4 may each additionally include an SCPAC config.

[0244] (1) An entry associated with condReconfig ID3 may include SCPAC config1, and SCPACconfig1 may include any one or more of the following information.

[0245] 1) SCPAC ID value: Here it is 1

[0246] 2) Apply the source PSCell instruction information of SCPAC config1 to it.

[0247] - For example, it can include CondReconfig ID3, or a combination of PCI and ARFCN information indicating PSCell3, or an RRCReconfiguration message indicating the reconfigurationWithSync field of PSCell3.

[0248] However, it may not include source PSCell indication information.

[0249] 3) A list of information used to move from the source PSCell (i.e., PSCell3) associated with SCPAC config1 to a specific target PSCell.

[0250] -ConditionalReconfig ID1, target PSCell 1 config (configuration information of PSCell1 used when moving from PSCell3 to PSCell1), information on the conditions that must be met when moving from PSCell3 to PSCell1.

[0251] -ConditionalReconfig ID2, target PSCell 4 config (the PSCell 4 configuration information used when moving from PSCell3 to PSCell4), information on the conditions that must be met when moving from PSCell3 to PSCell4.

[0252] (2) An entry associated with condReconfig ID4 may include SCPAC config2, and SCPACconfig2 may include any one or more of the following information.

[0253] 1) SCPAC ID value: Here it is 2

[0254] 2) Apply SCPAC config2 source PSCell instruction information to it.

[0255] - For example, it can include CondReconfig ID4, or a combination of PCI and ARFCN information indicating PSCell4, or an RRCReconfiguration message indicating the reconfigurationWithSync field of PSCell4.

[0256] However, it may not include source PSCell indication information.

[0257] 3) A list of information used to move from the source PSCell (i.e., PSCell4) associated with SCPAC config2 to a specific target PSCell.

[0258] -ConditionalReconfig ID1, target PSCell 1 config (configuration information of PSCell1 used when moving from PSCell4 to PSCell1), information on the conditions that must be met when moving from PSCell4 to PSCell1.

[0259] -ConditionalReconfig ID2, target PSCell 3 config (configuration information of PSCell3 used when moving from PSCell4 to PSCell3), information on the conditions that must be met when moving from PSCell4 to PSCell3.

[0260] current, Figure 9 Assume that the configuration of the candidate target PSCell used during SCPAC operations is given as an incremental configuration.

[0261] To this end, the network can deliver a reference configuration (or SCPAC reference config) for SCPAC separately in the conditional reconfiguration field. The endpoint can construct the final target PSCell configuration by incrementally adding the configuration of each candidate target PSCell present in the SCPAC config based on the SCPAC reference configuration, and can perform SCPAC by applying the final target PSCell configuration during SCPAC operation.

[0262] When a terminal receives an RRCReconfiguration message containing information, it can perform operations on short-term and long-term variables.

[0263] -Short-term variables

[0264] In the case of short-term variables, the terminal can store the condReconfig Id, candidate target PSCell conditions, and target set configuration (or configuration information) in VarConditionalReconfiguration or in short-term variables of all entries in conditional reconfiguration. For the condition information of this stored entry, measurement operations can be performed based on the measurement object (MO) associated with the measId that refers to the condition information, and the evaluation of events in the reportconfig associated with the measId can be started simultaneously.

[0265] -Long-term variables

[0266] In the case of long-term variables, when an entry in a conditional reconfiguration includes an SCPAC configuration field, the terminal can store the SCPAC configuration in a long-term variable. In this case, a list of SCPAC ID, source PSCell information, and {condReconfig ID, condition, target cell configuration of candidate target PSCell} can be stored. Furthermore, in the case of incremental configuration, an SCPAC reference configuration can be stored.

[0267] For example, such as Figure 9 As shown, the terminal can store the following information in short-term and long-term variables.

[0268] -Short-term variables

[0269] (1) Entries associated with condReconfig ID1 - condReconfig ID1, cond1, and PSCell 1config

[0270] (2) Entries associated with condReconfig ID2 - condReconfig ID2, cond2, and PSCell 2config

[0271] (3) Entries associated with condReconfig ID3 - condReconfig ID3, cond3, and PSCell 3config

[0272] (4) Entries associated with condReconfig ID4 - condReconfig ID4, cond4, and PSCell 4config

[0273] -Long-term variables

[0274] (1) SCPAC config1 - SCPAC ID1, (to which the source PSCell indication information of SCPAC config1 is applied), {ConditionalReconfig ID1, target PSCell 1 config, condition}, {ConditionalReconfigID2, target PSCell 4 config, condition}

[0275] (2) SCPAC config2 - SCPAC ID2, (to which the source PSCell indication information of SCPAC config2 is applied), {ConditionalReconfig ID1, target PSCell1 configuration, condition}, {ConditionalReconfig ID2, target PSCell3 configuration, condition}

[0276] (3) If necessary, refer to the SCPAC config.

[0277] Subsequently, when the terminal executes a CPC on a specific PSCell existing in the short-term variable or successfully executes a general PSCell change, the terminal can release all entries of the short-term variable. Here, successful execution of the PSCell change can refer to the sending of the RRCReconfigurationComplete message.

[0278] After successfully executing the PSCell change, the terminal can store some information of the long-term variable again in the released short-term variable.

[0279] Here, some information stored in short-term variables refers to the internal information of the SCPAC configuration, where the current PSCell to which the terminal moves by executing a PSCell change is indicated or associated as the source PSCell. In other words, it can be a list of {condReconfig ID, candidate target PSCell configuration, conditions for performing CPAC on that candidate target PSCell} in the SCPAC configuration, where the cell that has completed the move to the new PSCell is indicated as the source PSCell.

[0280] For example, such as Figure 9 As shown, the terminal can again store the following information as long-term variables in short-term variables.

[0281] When the terminal executes a PSCell change for PSCell3, since the current PSCell, PSCell3, is the source PSCell, the associated {ConditionalReconfig ID1, target PSCell 1 config, condition} and {ConditionalReconfig ID2, target PSCell 4 config, condition} can be stored in short-term variables.

[0282] After updating the short-term variables, the terminal can perform measurement and condition evaluation operations based on the condition information of each ID included in the short-term variables.

[0283] Figure 10 This is a view illustrating a subsequent conditional PSCell add and change (SCPAC) configuration method according to another embodiment of this disclosure.

[0284] More specifically, Figure 10 This refers to the situation where the subsequent conditional PSCell Add and Change (SCPAC) configuration is replaced with the id value used for incremental configuration.

[0285] Figure 10 The embodiments are methods for solving the following problems: when... Figure 9 The configuration information described, corresponding to the increment of each target PPSCell, is included in the SCPAC config and delivered to the terminal, and is repeatedly included and sent during signal transmission even if the final target PSCell configuration is the same for the same PSCell.

[0286] exist Figure 9 In this example, the target PSCell 1 config of SCPAC config1 is the same as the target PSCell1 config of SCPAC config2. In other words, when using the SCPAC reference configuration, the incremental target PSCell configuration is the same regardless of the source PSCell. Therefore, the final target PSCell configuration (= reference config + incremental config) is also the same for each target PSCell.

[0287] In this scenario, for semaphore reduction, instead of incremental configuration for each target PSCell in each SCPAC config, the ID of the target PSCell can be used as an indicator. Furthermore, the conditional reconfiguration field can include the SCPAC reference configuration separately. The terminal can derive the final PSCell configuration for a specific target PSCell by adding the incremental configuration indicated by the ID of that specific target PSCell to the SCPAC reference configuration.

[0288] When the terminal receives configuration information and stores the necessary information in long-term variables, the following method exists: store the received SCPAC reference configuration and incremental configuration separately, and store the corresponding PSCell ID of each target PSCell in each SCPAC config.

[0289] Instead, unlike when received, the SCPAC reference config and incremental configuration for each target PSCell can be combined to store the final target PSCell for each SCPAC config (e.g., in the form of an octet string RRCReconfiguration).

[0290] For example, such as Figure 10 As shown, when the current PSCell is PSCell 5, the conditional reconfiguration field may include a list of entries associated with the condReconfig ID and the SCPAC reference config.

[0291] (1) Related entries for condReconfig ID1 - condReconfig ID1, cond1, and PSCell 1config

[0292] (2) CondReconfig ID2 related entries - CondReconfig ID2, Cond2, and PSCell 2 config

[0293] (3) CondReconfigID3 related entries - condReconfigID3, cond3, PSCell 3 config and SCPAC config1

[0294] 3-1) SCPAC config1 may include the following information.

[0295] -SCPAC id1, (the source PSCell instruction information to which SCPAC config1 is applied), {ConditionalReconfig ID1, target PSCell 1 id1, condition}, {ConditionalReconfig ID2, target PSCell 1 id4, condition}

[0296] (4) Related entries for condReconfigID4 - condReconfigID4, cond4, PSCell 4 config and SCPAC config2

[0297] 4-1) SCPAC config2 may include the following information.

[0298] -SCPAC id2, (the source PSCell instruction information to which SCPAC config2 is applied), {ConditionalReconfig ID1, target PSCell 1 id1, condition}, {ConditionalReconfig ID2, target PSCell 1 id3, condition}

[0299] (5) SCPAC reference configuration, a list of {target PSCell id, incremental configuration for each target PSCell}

[0300] according to Figure 10 In one embodiment, the terminal can connect with Figure 9 Instead of storing the changed content in long-term variables, the target PSCell's ID can be stored during storage.

[0301] In another embodiment of this disclosure, the final target PSCell configuration, which combines the SCPAC reference configuration and the incremental configuration, can be stored. If the final target PSCell configuration is combined, it is not necessary to store separate SCPAC reference configurations and lists of {target PSCell id, incremental config for each target PSCell} in long-term variables.

[0302] For example, such as Figure 10 As shown, the following information can be stored in long-term variables.

[0303] (1) SCPAC config1 - SCPAC id1, (to which the source PSCell instruction information of SCPAC config1 is applied), {ConditionalReconfig ID1, target PSCell id 1 (or final target PSCell config), condition}, {ConditionalReconfig ID2, target PSCell id 4 (or final target PSCell config), condition}

[0304] (2) SCPAC config2 - SCPAC id2, (to which the source PSCell instruction information of SCPAC config2 is applied), {ConditionalReconfig ID1, target PSCell id1 (or final target PSCell config), condition}, {ConditionalReconfig ID2, target PSCell id3 (or final target PSCell config), condition}

[0305] (3) When storing the target PSCell ID, SCPAC reference config, and a list of {target PSCell ID, incremental config for each target PSCell}

[0306] Operations on short-term variables and Figure 9 The same applies. In other words, it can store the ID, condition, and target PSCell configuration for all entries that can be conditionally reconfigured, and can perform measurement and condition evaluation operations based on the corresponding condition information.

[0307] If a PSCell change occurs, the terminal can release all entries in the short-term variable and store only the contents of the SCPAC config from the source cell of the PSCell in the long-term variable that was successfully changed.

[0308] At this point, storing some contents of the SCPAC config from long-term variables to short-term variables can be done in different ways depending on the format of the long-term variables mentioned earlier.

[0309] If the SCPAC reference configuration and incremental configuration are stored in long-term variables, and the target PSCell ID is stored in the entry for each SCPAC config, then the terminal can export the final PSCell configuration that combines the reference configuration and incremental configuration stored in the long-term variables as the target PSCell configuration corresponding to each condReconfig ID, and store it in short-term variables.

[0310] If the target PSCell configuration is stored in a long-term variable as the final target PSCell configuration instead of the target PSCell ID in each SCPAC config, the terminal can store the target PSCell configuration stored for each condReconfig ID in a short-term variable as the final target PSCell configuration, instead of the target PSCell ID. In this case, the final target PSCell configuration is the complete configuration, not the incremental configuration corresponding to the reference, and in which the final configuration or complete configuration is considered to be all parts of all candidate target PSCell configurations mentioned in this specification, an additional 1-bit indicator indicating whether the configuration is a complete configuration can be added. This can be added for each corresponding entry, and is possible for both short-term and long-term variable cases.

[0311] For example, such as Figure 10 As shown, the terminal can again store the following information as long-term variables in short-term variables.

[0312] When the terminal executes a PSCell change for PSCell3, since the current PSCell, PSCell3, is the source PSCell, the associated {ConditionalReconfig ID1, target PSCell 1 config, condition} and {ConditionalReconfig ID2, target PSCell 4 config, condition} can be stored in short-term variables.

[0313] Figure 11 This is a view illustrating a subsequent conditional PSCell add and change (SCPAC) configuration method according to another embodiment of this disclosure.

[0314] More specifically, Figure 11 This is a view illustrating the scenario where the target PSCell configuration is delivered to the terminal as a complete configuration from the outset without a reference configuration.

[0315] Instead of passing Figure 10 An embodiment of the information consisting of a reference configuration and incremental configuration for each candidate target PSCell, obtained through a conditional reconfiguration field, allows for the delivery of a complete configuration to the terminal for each candidate target PSCell. For this purpose, a separate ID can be assigned to the complete configuration of each candidate target PSCell. Furthermore, this ID can be referred to as the configuration information of the target PSCell in each SCPAC config.

[0316] For example, such as Figure 11As shown, when the current PSCell is PSCell 5, the conditional reconfiguration field can include a list of entries associated with the condReconfig ID and the SCPAC full configuration.

[0317] (1) CondReconfig ID1 related entries - condReconfig ID1, cond1, and PSCell 1config, {SCPAC availability}

[0318] (2) CondReconfigID2 related entries - condReconfigID2, cond2, and PSCell 2 config, {SCPAC availability}

[0319] (3) CondReconfigID3 related entries - condReconfigID3, cond3, PSCell 3 config and SCPAC config1

[0320] 3-1) SCPAC config1 may include the following information.

[0321] -SCPAC id1, (the source PSCell instruction information to which SCPAC config1 is applied), {ConditionalReconfig ID1, fullconfig ID1, condition}, {ConditionalReconfig ID2, fullconfig ID4, condition}

[0322] (4) Related entries for condReconfigID4 - condReconfigID4, cond4, PSCell 4 config and SCPAC config2

[0323] 4-1) SCPAC config2 may include the following information.

[0324] -SCPAC id2, (the source PSCell instruction information to which SCPAC config2 is applied), {ConditionalReconfig ID1, fullconfig ID1, condition}, {ConditionalReconfig ID2, fullconfig ID3, condition}

[0325] (5) SCPAC full configuration: a list of {id, candidate PSCell configuration (octet string)}

[0326] According to another embodiment of this disclosure, the source cell configuration information of the SCPAC config may be referred to as the target PSCell configuration information in each SCPAC config.

[0327] For example, if the source cell information of the SCPAC config is an octet of the complete configuration of the PSCell used when moving to that PSCell, then the configuration to be used when moving to each target PSCell used in subsequent SCPAC operations could refer to the SCPAC config ID that uses each corresponding PSCell as the source PSCell. For instance, if the source cell of a particular SCPAC config is PSCell 3, and it is the configuration applied by the terminal when moving to that PSCell 3 (e.g., an octet of RRCReconfiguration), then when considering PSCell 3 as a candidate target PSCell in other SCPAC configs, the SCPAC config ID that uses the configuration used when moving to that PSCell 3 as the source information could be used.

[0328] More specifically, see reference Figure 11 SCPAC config1 and SCPAC config2 can include SCPAC id instead of fullconfig ID.

[0329] 3-1) SCPAC config1 may include the id of the SCPAC config that uses the corresponding target PSCell as the source PSCell, instead of the aforementioned fullconfig ID1. In other words, it may include the id of the SCPAC config that uses PSCell 1 as the source PSCell.

[0330] 3-2) Similarly, SCPAC config1 may include the id of the SCPAC config that uses the corresponding target PSCell as the source PSCell, instead of the aforementioned fullconfig ID4. In other words, it may include the id of the SCPAC config that uses PSCell 4 as the source PSCell.

[0331] 4-1) SCPAC config2 may include the id of the SCPAC config that uses the corresponding target PSCell as the source PSCell, instead of the aforementioned fullconfig ID1. In other words, it may include the id of the SCPAC config that uses PSCell 4 as the source PSCell.

[0332] 4-2) Similarly, SCPAC config2 may include the id of the SCPAC config that uses the corresponding target PSCell as the source PSCell, instead of the aforementioned fullconfig ID4. In other words, it may include the id of the SCPAC config that uses PSCell 4 as the source PSCell.

[0333] In the following text, the operations on long-term and short-term variables are discussed. Figure 9 and Figure 10 The operations described herein are the same.

[0334] Figure 12 This is a view illustrating a subsequent conditional PSCell add and change (SCPAC) configuration method according to another embodiment of this disclosure.

[0335] More specifically, Figure 12 A method for increasing the degree of freedom in SCPAC config configuration is proposed.

[0336] In the above embodiments, an SCPAC configuration is proposed as a configuration available after moving to a specific target PSCell in the conditional reconfiguration field. According to the above embodiments, the network cannot deliver the necessary SCPAC configuration before moving to the corresponding target PSCell.

[0337] For example, if the terminal is currently in PSCell 5, the information provided as part of the SCPAC configuration may only indicate the subsequent SCPAC configuration after moving to PSCell 3 or PSCell 4. The information required when moving from PSCell 5 to another PSCell may not be signaled using the current configuration.

[0338] To address this issue, even if the SCPACconfig field is not present in a specific entry during conditional reconfiguration, adding a separate instruction allows the conditions to be met when moving to the target PSCell of that entry and the target PSCell configuration information to be used as is for information about the SCPAC config.

[0339] For example, in Figure 12 In this context, for condReconfig IDs 1 and 2, if a separate availability indicator exists, the conditional information used to move to the corresponding target PSCell and the target PSCell configuration information are considered entries for the SCPAC config. Therefore, the terminal can store the corresponding SCPAC config in a long-term variable. At this point, the terminal can internally assign a predefined ID to the SCPAC ID.

[0340] More specifically, such as Figure 12 As shown, when the current PSCell is PSCell 5, the conditional reconfiguration field can include a list of entries associated with the condReconfig ID and the SCPAC reference config.

[0341] (1) Related entries for condReconfigID1 - availability of condReconfigID1, cond1, PSCell 1 config, and SCPAC

[0342] (2) condReconfigID2 related entries - condReconfigID2, cond2, PSCell 2 config and SCPAC availability

[0343] (3) CondReconfigID3 related entries - condReconfigID3, cond3, PSCell 3 config and SCPAC config1

[0344] (4) Related entries for condReconfigID4 - condReconfigID4, cond4, PSCell 4 config and SCPAC config2

[0345] (5)SCPAC reference config

[0346] After that, as Figure 12 As shown, for condReconfig IDs 1 and 2, due to the existence of separate SCPAC availability, the following new entries can be stored separately in the terminal's long-term variables. Assume the predefined SCPAC ID is SCPAC ID0.

[0347] -SCPAC id0, (indicating information about the source cell (i.e., the current PSCell PSCell5)), {ConditionalReconfig ID1, target PSCell 1 config, condition 1}, {ConditionalReconfig ID2, target PSCell 2 config, condition 2}

[0348] Operations on short-term variables and Figure 7 The same applies. In other words, it can store the ID, condition, and target PSCell configuration for all entries that can be conditionally reconfigured, and can perform measurement and condition evaluation operations based on the corresponding condition information.

[0349] According to another embodiment of this disclosure, since the information included in the conditional reconfiguration field based on the current PSCell 5 is about moving to another PSCell, it is not necessary to deliver configuration information about SCPAC movement from the current own PSCell (i.e., PSCell 5) to other candidate PSCells.

[0350] To address this issue, the network can leave the conditional field or the target PSCell configuration field empty in a specific entry within the conditional reconfiguration field and add an SCPAC config field to that entry. In this case, the terminal can recognize the corresponding SCPAC config as the configuration for an SCPAC move from the current PSCell to another PSCell.

[0351] Based on this, the terminal can store the corresponding SCPAC configuration in a long-term variable.

[0352] According to another embodiment of this disclosure, the SCPACToAddMod field and the SCPACToRelease field may be introduced.

[0353] More specifically, in all of the above Figures 9 to 12 In this case, the SCPACToAddMod and SCPACToRelease fields can be introduced as upper-level fields. They are subfields of the SCPAC config and also include content that is recommended to be included in the SCPAC config.

[0354] SCPACToAddMod can include the content mentioned above, and when it is necessary to add / modify an entry in an SCPAC config, it can include the information to be added / modified and deliver it to the terminal.

[0355] For example, if the information for SCPAC id 1 is already stored in a long variable, and that information is {condReconfigId 1, target PSCell 1 config, condition 1}, {condReconfig Id 2, target PSCell 2 config, condition 2}, then when SCPAC id 1 is recorded in the newly received SCPACToAddMod field and includes {condReconfig Id 3, target PSCell 3, condition 3}, the terminal can add the new entry information for condReconfig Id 3 to the entry for SCPAC id 1.

[0356] If information including a previously stored condReconfig ID is delivered in the SCPACToAddMod field, the terminal can replace the entry information for the corresponding condReconfig ID with the new entry.

[0357] If the terminal receives an SCPAC id included in the SCPACToRelease field, the terminal can release the entire SCPAC config corresponding to the SCPAC id existing in the current long-term variable. Furthermore, when an SCPAC id is included in the SCPACToRelease field and a specific condReconfig Id is additionally included and delivered to the terminal, the terminal can delete the entry corresponding to the specific condReconfig Id from the entries for the corresponding SCPAC id.

[0358] When a terminal performs an operation to update or delete information in a long-term variable, if the current PSCell adds, modifies, or releases an SCPAC config entry that is indicated as the source PSCell, the terminal should also add, modify, or release the corresponding entry in the current short-term variable.

[0359] Long-term variables can release all entries upon receiving an RRC release and upon performing an RRC rebuild operation.

[0360] On the other hand, short-term variables can release all entries when an RRC release is received, in the case of an RRC reconstruction, and when a PSCell change is performed.

[0361] Figure 13 This is a flowchart illustrating the process of subsequent conditional PSCell Addition and Modification (SCPAC) operations of an execution terminal according to an embodiment of the present disclosure.

[0362] More specifically, Figure 13 This diagram illustrates the scenario where the terminal receives subsequent PSCell Add and Change (SCPAC) configurations and executes SCPAC operations.

[0363] In step 1310, firstly, the user equipment (UE) 1301 is in a dual-connectivity state with a source-primary node (S-MN) 1303 and a source-secondary node (S-SN) 1305 configured. (Dual-connectivity configuration)

[0364] In step 1315, a preparation process can be performed for the combination of a Conditional PSCell Change and Addition (CPAC) configuration and a subsequent CPAC (SCPAC) configuration initiated by MN or SN. (SCPAC preparation between MN and SN)

[0365] In step 1320, terminal 1301 can receive an RRC reconfiguration message from S-MN 1305, which includes conditional reconfiguration and SCPAC configuration information (including RRCReconfiguration with SCPAC config).

[0366] More specifically, S-MN 1305 can deliver CPAC and SCPAC configuration information to terminal 1301 via the conditional reconfiguration field of the RRCReconfiguration message.

[0367] In step 1325, the terminal 1301 that has received the information can use the above-mentioned... Figures 7 to 10 One of the methods proposed in the paper stores information in short-term and long-term variables. Terminal 1301 can perform measurement and condition determination operations on the source PSCell and candidate target PSCell based on the conditional information stored in the short-term variables.

[0368] Subsequently, in step 1330, when the conditions of a candidate PSCell for a specific CPAC are met (or satisfied), terminal 1301 may perform a PSCell change for that PSCell.

[0369] At this point, terminal 1301 can release all entries of the existing short-term variables and add information from the long-term variables to the short-term variables from the SCPAC config, which will indicate the current PSCell of the completed connection as the source PSCell.

[0370] In step 1335, a random access procedure can be performed between terminal 1301 and the new target secondary node 1 (T-SN1) 1307.

[0371] In step 1340, terminal 1301 may send an RRCReconfigurationComplete message to T-SN11307.

[0372] Although steps 1335 and 1340 are shown as being performed after step 1330, the scope of this disclosure is not limited thereto. Steps 1335 and 1340 may include the process of performing PSCell changes in step 1330, and terminal 1301 may release all entries of short-term variables and add some information of long-term variables after sending the RRCReconfigurationComplete message to T-SN11307.

[0373] In step 1345, based on the information in the added short-term variables, terminal 1301 can continue the measurement and evaluation operations for the conditions corresponding to SCPAC.

[0374] The methods described in the embodiments of this disclosure or in the claims can be implemented in hardware, software, or a combination of hardware and software.

[0375] When implemented in software, a computer-readable storage medium may be provided to store one or more programs (software modules). The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions that enable the electronic device to perform methods according to embodiments described in the specification or claims of this disclosure.

[0376] The program (software module or software) can be stored in random access memory, including non-volatile memory such as flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), disk storage devices, optical disc ROM, digital versatile optical disc (DVD), or other types of optical storage devices or magnetic tape cartridges. Alternatively, the program can be stored in a memory consisting of all or some of these components. Multiple such components may be present.

[0377] The program can be stored in an attachable storage device accessible via a communication network, such as the Internet, intranet, local area network (LAN), wide area network (WLAN), or storage area network (SAN), or a combination thereof. The storage device can be connected to a device executing embodiments of this disclosure via an external port. A separate storage device on the communication network can be connected to a device executing embodiments of this disclosure.

[0378] In the specific embodiments described above, the components included in this disclosure are represented in a singular or plural form according to the proposed specific embodiments. However, the singular or plural forms are chosen to suit the context presented for ease of description, and the invention is not limited to singular or plural components. As used herein, the singular forms “a,” “an,” and “the” are intended to also include the plural forms, unless the context clearly indicates otherwise.

[0379] Although specific embodiments of the invention have been described above, various modifications can be made thereto without departing from the scope of the invention. Therefore, the scope of this disclosure should not be limited to the above embodiments, but should be defined by the appended claims and their equivalents.

Claims

1. A method for a user equipment (UE) in a wireless communication system, the method comprising: Receive Radio Resource Control (RRC) reconfiguration messages from the base station. The RRC reconfiguration messages include configuration information for conditional handover of CHO via candidate secondary cell group (SCG). Upon the occurrence of SCG failure in the UE, an SCG failure message is sent to the base station; and Stop measuring candidate primary and secondary cells PSCells when sending SCG failure information.

2. The method of claim 1, wherein, SCG failure occurs when at least one of the following occurs: radio link failure (RLF) in the SCG connection, SCG reconfiguration failure, beam failure of the PSCell when the SCG is deactivated, and SCG integrity check failure.

3. The method of claim 1, wherein, The configuration information used for CHO via candidate SCG includes at least one of the following: a list of candidate primary cell PCell configurations and candidate PSCell configurations, a list of target PCell conditions and target PSCell conditions, and a conditional reconfiguration ID.

4. The method according to claim 1, further comprising: Stop conditional evaluation of candidate PCells and candidate PSCells determined based on configuration information used for CHOs via candidate SCGs.

5. A method for a user equipment (UE) in a wireless communication system, the method comprising: The radio resource control (RRC) reconfiguration message is received from the base station. The RRC reconfiguration message includes configuration information for conditional handover of CHO via candidate secondary cell group (SCG). The system sends an MCG failure message to the base station based on the occurrence of the UE's primary cell group (MCG). and Stop condition assessment of CHO via SCG.

6. The method according to claim 5, wherein, MCG failure information is transmitted via Separate Signaling Radio Bearer 1 SRB1 or SRB3.

7. The method according to claim 5, wherein, The configuration information used for CHO via candidate SCG includes at least one of the following: a list of candidate primary cell PCell configurations and candidate PSCell configurations, a list of target PCell conditions and target PSCell conditions, and a conditional reconfiguration ID.

8. The method of claim 1, further comprising stopping the conditional evaluation of candidate PCell and candidate PSCell determined based on configuration information for CHO via candidate SCG.

9. A user equipment (UE) in a wireless communication system, comprising: transceiver; and Controller, wherein the controller is configured to: Receive Radio Resource Control (RRC) reconfiguration messages from the base station. The RRC reconfiguration messages include configuration information for conditional handover of CHO via candidate secondary cell group (SCG). Control is based on the occurrence of UE-based SCG failure, and SCG failure information is sent to the base station; and Stop measuring candidate primary and secondary cells PSCells when sending SCG failure information.

10. The UE according to claim 9, wherein, SCG failure occurs when at least one of the following occurs: radio link failure (RLF) in the SCG connection, SCG reconfiguration failure, beam failure of the PSCell when the SCG is deactivated, and SCG integrity check failure.

11. The UE according to claim 9, wherein, The configuration information used for CHO via candidate SCG includes at least one of the following: a list of candidate primary cell PCell configurations and candidate PSCell configurations, a list of target PCell conditions and target PSCell conditions, and a conditional reconfiguration ID.

12. The UE according to claim 9, wherein, The controller is configured to stop conditional evaluation of candidate PCells and candidate PSCells based on configuration information used for CHOs via candidate SCGs.

13. A user equipment (UE) in a wireless communication system, comprising: transceiver; and Controller, wherein the controller is configured to: The radio resource control (RRC) reconfiguration message is received from the base station. The RRC reconfiguration message includes configuration information for conditional handover of CHO via candidate secondary cell group (SCG). The control sends MCG failure information to the base station based on the occurrence of the UE's primary cell group MCG failure; and Stop condition assessment of CHO via SCG.

14. The UE according to claim 13, wherein, MCG failure information is transmitted via Separate Signaling Radio Bearer 1 SRB1 or SRB3.

15. The UE according to claim 13, wherein, The configuration information used for CHO via candidate SCG includes at least one of the following: a list of candidate primary cell PCell configurations and candidate PSCell configurations, a list of target PCell conditions and target PSCell conditions, and a conditional reconfiguration ID.

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