Method for providing cell group activation or deactivation service in wireless communication system and apparatus therefor

Abstract

To provide a method and apparatus for providing a cell group activation service or deactivation service in a wireless communication system.SOLUTION: A method for a first base station MN executing dual access in a wireless communication system includes a step of transmitting, to a second base station SN, a request message associated with the dual access, a step of receiving, from the second base station, a response message including configuration information on a second cell group (SCG) for the dual acces, a step of identifying whether the response message includes information related to a state of the SCG, and a step of transmitting, to a terminal UE, a radio resource control (RRC) message including the configuration information on the SCG and the information related to the state of the SCG. In the case that an RRC message includes an indicator indicating deactivation of the SCG, the configuration information on the SCG includes information not to perform QoS flow remapping on a data radio bearer (DBR) associated with the SCG.SELECTED DRAWING: Figure 1K

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for providing cell group activation or deactivation services in a wireless communication system. [Background technology]

[0002] Looking back at the evolution of wireless communication from one generation to the next, technologies have been developed primarily for human-oriented services, such as voice, multimedia, and data. th Following the commercialization of the 6G (6G) communication system, the number of connected devices, which has been increasing explosively, is expected to be connected to the communication network. Examples of connected devices include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction machinery, and factory equipment. Mobile devices are expected to evolve with various home factors such as augmented reality glasses, virtual reality headsets, and holographic devices. th In the 2020 (5G) generation era, efforts are underway to develop improved 6G communication systems to connect hundreds of billions of devices and objects and provide a variety of services. For this reason, 6G communication systems are being called beyond 5G systems.

[0003] The 6G communication system, which is expected to be realized around 2030, will have a maximum transmission speed of tera (i.e., 1,000 Gbps) bps and a wireless latency of 100 microseconds (μsec). In other words, compared to the 5G communication system, the transmission speed in the 6G communication system will be 50 times faster and the wireless latency will be one-tenth of that of the 5G communication system.

[0004] To achieve such high data transmission speeds and ultra-low latency, 6G communication systems are being considered for implementation in the terahertz band (e.g., 95 GHz to 3 THz). Compared to the millimeter wave (mmWave) band introduced in 5G, the terahertz band has more severe path loss and atmospheric absorption, making technology to ensure signal reach, or coverage, even more important. Key technologies to ensure coverage include new waveforms, beamforming, and multiple-antenna transmission technologies such as massive MIMO (multiple-input and multiple-output), full-dimensional MIMO (multiple-input and multiple-output), array antennas, and large-scale antennas that offer better coverage than radio frequency (RF) elements, antennas, and orthogonal frequency division multiplexing (OFDM). Other new technologies being discussed to improve terahertz signal coverage include metamaterial-based lenses and antennas, high-dimensional spatial multiplexing using orbital angular momentum (OAM), and reconfigurable intelligent surfaces (RIS).

[0005] In addition, to improve spectrum efficiency and system networks, 6G communication systems are being developed with a variety of technologies in mind, including full duplex technology, which allows uplink and downlink to simultaneously use the same frequency resources at the same time; network technology that integrates satellites and high-altitude platform stations (HAPS); innovative network structure technology that supports mobile base stations and enables network operation optimization and automation; dynamic spectrum sharing technology that avoids collisions based on spectrum usage prediction; AI-based communication technology that utilizes artificial intelligence (AI) from the design stage and incorporates end-to-end AI support functions to achieve system optimization; and next-generation distributed computing technology that enables services with complexity that exceeds the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources (such as mobile edge computing (MEC) and the cloud). Furthermore, efforts are underway to further strengthen connectivity between devices, further optimize networks, promote the softwarization of network entities, and increase the openness of wireless communications through the design of new protocols to be used in 6G communication systems, the realization of a hardware-based security environment, the development of mechanisms for safe data utilization, and technological development related to methods for maintaining privacy.

[0006] Research and development into 6G communication systems is expected to enable the next hyper-connected experience through the hyper-connectivity of 6G communication systems, which will include not only connections between things (M2M) but also between people and things (P2M). Specifically, 6G communication systems are expected to provide services such as truly immersive XR (extended reality), high-fidelity mobile holograms, and digital replicas. Furthermore, services such as remote surgery, industrial automation, and emergency response, which will be provided through 6G communication systems with enhanced security and reliability, will be applied in a variety of fields, including industry, medicine, automobiles, and home appliances.

[0007] The preceding information is presented solely as background information to aid in the understanding of the present disclosure, and no determination has been made, or any assertion made, as to whether any of the foregoing is applicable as prior art to the present disclosure. Summary of the Invention [Problem to be solved by the invention]

[0008] In next-generation wireless communication systems, carrier aggregation (CA) or dual connectivity (DC) may be utilized to provide a terminal with a high data transmission rate and low transmission delay. However, a method is needed to prevent processing delays that may occur when a terminal connected to a network configures and activates carrier aggregation or dual connectivity, or when a terminal uses and deactivates carrier aggregation or dual connectivity. In particular, if a terminal maintains multiple cells in an active state to use carrier aggregation or dual connectivity, the terminal must monitor a physical downlink control channel (PDCCH) for each cell, resulting in significant battery consumption. Meanwhile, if multiple cells are maintained in an inactive state to reduce battery consumption, data transmission and reception delays may occur due to the delays that occur when activating multiple cells when using carrier aggregation or dual connectivity. [Means for solving the problem]

[0009] Aspects of the present disclosure address at least the problems and / or shortcomings described above and provide at least the advantages described below. Accordingly, aspects of the present disclosure provide methods and apparatus for providing activation or deactivation services for a group of cells in a wireless communication system.

[0010] Additional aspects will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the presented embodiments.

[0011] According to one aspect of the present disclosure, there is provided a method for a first base station to perform dual access in a wireless communication system, the method including: transmitting a request message for the dual access to a second base station; receiving a response message from the second base station, the response message including configuration information of a second cell group (SCG) for the dual access; identifying whether the response message includes information on a state of the SCG; and transmitting a Radio Resource Control (RRC) message to a terminal, the RRC message including the configuration information of the SCG and information on the state of the SCG, wherein the configuration information of the SCG includes information not to perform QoS flow remapping on a Data Radio Bearer (DRB) associated with the SCG if the RRC message includes an indicator indicating deactivation of the SCG.

[0012] According to one aspect of the present disclosure, there is provided a method for a terminal to perform dual access in a wireless communication system, the method including: receiving a Radio Resource Control (RRC) message including configuration information of a second cell group (SCG) and information about a state of the SCG based on a message from a second base station constituting a second cell group; and transmitting an RRC response message including information on whether the configuration of the SCG is successful or not, wherein the configuration information of the SCG includes information not to perform QoS flow remapping on a Data Radio Bearer (DRB) associated with the SCG if the RRC message includes an indicator indicating deactivation of the SCG.

[0013] According to another aspect of the present disclosure, there is provided an apparatus, comprising: a first base station for performing dual access in a wireless communication system, the first base station comprising: a transceiver unit; and at least one processor coupled to the transceiver unit, wherein the at least one processor transmits a request message for the dual access to a second base station, receives from the second base station a response message including configuration information for a second cell group (SCG) for the dual access, identifies whether the response message includes information regarding a state of the SCG, and transmits a radio resource control (RRC) message to a terminal including the configuration information of the SCG and information regarding the state of the SCG, wherein the configuration information of the SCG includes information to not perform QoS flow remapping on a data radio bearer (DRB) associated with the SCG if the RRC message includes an indicator indicating deactivation of the SCG.

[0014] Other aspects, advantages and salient features of the present disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the drawings, discloses various embodiments of the present disclosure. [Brief explanation of the drawings]

[0015] [Figure 1A] FIG. 1 illustrates the structure of an LTE system according to one embodiment of the present disclosure. [Figure 1B] FIG. 1 illustrates a radio protocol structure in an LTE system according to one embodiment of the present disclosure. [Figure 1C] FIG. 1 illustrates the structure of a next-generation wireless communication system according to an embodiment of the present disclosure. [Figure 1D] FIG. 1 illustrates a radio protocol structure of a next-generation wireless communication system according to one embodiment of the present disclosure. [Figure 1E] FIG. 1 illustrates a procedure for efficiently using a fairly wide frequency bandwidth to serve terminals in a next-generation wireless communication system according to one embodiment of the present disclosure. [Figure 1F]FIG. 10 is a diagram showing a procedure for a terminal to switch from an RRC idle mode to an RRC connected mode in a next-generation wireless communication system according to one embodiment of the present disclosure, and showing a procedure for configuring bearer configuration information, cell group configuration information or cell configuration information, or channel measurement configuration information for connection in the terminal. [Figure 1G] FIG. 10 illustrates a partial bandwidth state transition or partial bandwidth switching procedure according to one embodiment of the present disclosure. [Figure 1H] 1 is a diagram illustrating a DRX setting or DRX operation method that can save the battery of a terminal according to one embodiment of the present disclosure. [Figure 1I] FIG. 10 is a diagram illustrating the concept of a method for operating a dormant partial bandwidth in an activated SCell or PSCell according to one embodiment of the present disclosure. [Figure 1J] FIG. 10 illustrates a method for operating an RRC inactive mode terminal according to one embodiment of the present disclosure. [Figure 1K] A diagram showing a signaling procedure for setting up or canceling dual connectivity technology in a next-generation wireless communication system, or for activating or resuming, or suspending or deactivating a secondary cell group set up for dual connectivity technology, according to one embodiment of the present disclosure. [Figure 1L] A diagram showing a second signaling procedure for setting up or deactivating dual connectivity technology, or setting up or deactivating, activating or resuming, or suspending or deactivating a secondary cell group set up for dual connectivity technology, according to one embodiment of the present disclosure. [Figure 1M] A diagram showing a third signaling procedure for setting up or deactivating dual connectivity technology, or setting up or deactivating, activating or resuming, or suspending or deactivating a secondary cell group set up for dual connectivity technology, according to one embodiment of the present disclosure. [Figure 1N] FIG. 10 illustrates the operation of a terminal according to an embodiment of the present disclosure. [Figure 1O]FIG. 2 illustrates the structure of a terminal according to an embodiment of the present disclosure. [Figure 1P] FIG. 1 is a diagram showing a block configuration of a base station in a wireless communication system according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] The following description with reference to the drawings is provided to aid in a comprehensive understanding of various embodiments of the present disclosure. To aid in this understanding, various specific details are included, but they are considered to be merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of the present disclosure. Furthermore, descriptions of well-known functions and structures are omitted for clarity and conciseness.

[0017] The following description and the terms and words used are not limited to a bibliographical meaning, but are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustrative purposes only, and is not provided for the purpose of limiting the present disclosure.

[0018] The singular forms "a," "an," and "the" should be understood to include plural references unless the context clearly dictates otherwise. Thus, for example, a reference to a "component surface" includes a reference to one or more of such surfaces.

[0019] In the description of the present disclosure, detailed descriptions of related art will be omitted if it is determined that the essence of the present disclosure will be unnecessarily obscured. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0020] Throughout this disclosure, the phrase "at least one of a, b, or c" refers to a only, b only, c only, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0021] In this specification, layers are also referred to as entities.

[0022] In the following, terms identifying access nodes, network entities, messages, interfaces between network entities, and various parts of identification information used in the following description are exemplified for the sake of convenience. Therefore, the present disclosure is not limited to the terms described below, and other terms may be used to indicate objects having equivalent technical meanings.

[0023] Hereinafter, for convenience of explanation, this disclosure will use terms and names defined in the 3GPP (registered trademark) LTE (3rd Generation Partnership Project Long Term Evolution) standard. However, this disclosure is not limited by these terms and names and may be equally applied to systems based on other standards. In this disclosure, for convenience of explanation, eNB (evolved node B) will be used interchangeably with gNB (next-generation node B). That is, a base station described as eNB refers to a gNB.

[0024] In this disclosure, a cell refers to a PCell (primary cell) or an SCell (secondary cell) (e.g., an SCell configured in a master cell group (MCG)), or a PSCell (e.g., a PCell in a secondary cell group (SCG)), or an SCell (e.g., an SCell configured in a secondary cell group (SCG)).

[0025] FIG. 1A is a diagram illustrating the structure of an LTE system according to one embodiment of the present disclosure.

[0026] 1A, the radio access network of the LTE system includes next-generation base stations (Evolved Node Bs (eNBs), or BSs) 1a-05, 1a-10, 1a-15, and 1a-20, a mobility management entity (MME) 1a-25, and a serving gateway (S-GW) 1a-30. A user equipment (UE or terminal) 1a-35 connects to (accesses) an external network via the eNBs 1a-05 to 1a-20 and the S-GW 1a-30.

[0027] In FIG. 1A, eNBs 1a-05 to 1a-20 correspond to existing Node Bs of a universal mobile telecommunications system (UMTS). The eNBs are connected to UEs 1a-35 via radio channels and play a more complex role than existing Node Bs. In an LTE system, all user traffic, including real-time services such as voice over Internet Protocol (VoIP), is served via a shared channel. Therefore, an entity that collects and schedules status information such as UE buffer status, available transmission power status, and channel status is required. The eNBs 1a-05 to 1a-20 are responsible for this function. One eNB typically controls multiple cells. To achieve a transmission speed of, for example, 100 Mbps, the LTE system uses orthogonal frequency division multiplexing (OFDM) as a radio access technology in a 20 MHz bandwidth. In addition, an adaptive modulation and coding (AMC) method is applied, which determines the modulation scheme and channel coding rate according to the channel state of the terminal. The S-GW 1a-30 is a device that provides a data bearer and creates or deletes the data bearer under the control of the MME 1a-25. The MME 1a-25 is a device that handles various control functions as well as mobility management functions for the UE 1a-35, and is connected to multiple base stations.

[0028] FIG. 1B is a diagram illustrating a radio protocol structure in an LTE system according to one embodiment of the present disclosure.

[0029] Referring to Figure 1B, the radio protocols of the LTE system include packet data convergence protocol (PDCP) 1b-05, 1b-40, radio link control (RLC) 1b-10, 1b-35, medium access control (MAC) 1b-15, 1b-30, and physical (PHY) 1b-20, 1b-25 in the UE (terminal) and LTE eNB, respectively. The PDCP layers 1b-05, 1b-40 are responsible for operations such as Internet protocol (IP) header compression / decompression. The main functions of the PDCP layers 1b-05, 1b-40 are summarized as follows:

[0030] -Header compression and decompression functions: ROHC (robust header compression) only

[0031] -User data transfer function (transfer of user data)

[0032] In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM

[0033] -For split bearers in DC (only support for RLC AM): PDCP PDU routing for transmission and PDCP PDU reordering for reception

[0034] Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM

[0035] -Retransmission of PDCP SDUs at handover and, for split bearers in DC, of ​​PDCP PDUs at PDCP data-recovery procedure, for RLC AM

[0036] -Ciphering and deciphering functions

[0037] -Timer-based SDU discard in uplink

[0038] The RLC (Radio Link Control) layers 1b-10 and 1b-35 reconstruct PDCP PDUs (protocol data units) or RLC SDUs (service data units) to the appropriate size and perform ARQ operations, etc. The main functions of the RLC are summarized as follows:

[0039] -Transfer of upper layer PDUs

[0040] -Error Correction through ARQ (only for AM data transfer)

[0041] - Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer)

[0042] -Re-segmentation of RLC data PDUs (only for AM data transfer)

[0043] -Reordering of RLC data PDUs (only for UM and AM data transfer)

[0044] -Duplicate detection (only for UM and AM data transfer)

[0045] -Protocol error detection (only for AM data transfer)

[0046] -RLC SDU deletion function (RLC SDU discard (only for UM and AM data transfer))

[0047] -RLC re-establishment function

[0048] The MAC layers 1b-15 and 1b-30 are connected to various RLC layers configured in one terminal and perform the operations of multiplexing RLC PDUs into MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The main functions of the MAC are summarized as follows:

[0049] -Mapping function between logical channels and transport channels

[0050] -Multiplexing / demultiplexing of MAC SDUs belonging to one or different logical channels into / from transport blocks (TB) delivered to / from the physical layer on transport channels

[0051] -Scheduling information reporting function

[0052] -Error correction through HARQ

[0053] -Priority handling between logical channels of one UE

[0054] Priority handling between UEs by means of dynamic scheduling

[0055] -MBMS service identification function

[0056] -Transport format selection function

[0057] -Padding function

[0058] The PHY (Physical) layers 1b-20 and 1b-25 perform the operations of channel coding and modulating upper layer data to form OFDM symbols and transmitting them over a wireless channel, or demodulating and channel decoding OFDM symbols received over a wireless channel and transmitting them to an upper layer.

[0059] FIG. 1C is a diagram illustrating the structure of a next-generation wireless communication system according to one embodiment of the present disclosure.

[0060] 1C, the radio access network of the next-generation wireless communication system (NR system or 5G system) is composed of a next-generation base station (NR gNB or NR base station (New Radio Node B)) 1c-10 and an NR CN (new radio core network) 1c-05. A user terminal (NR UE (new radio user equipment) or terminal) 1c-15 connects to (accesses) an external network via the NR gNB 1c-10 and the NR CN 1c-05.

[0061] In FIG. 1C, the NR gNB 1c-10 corresponds to an evolved node B (eNB) in a conventional LTE system. The NR gNB 1c-10 is connected to the NR UE 1c-15 via a radio channel and provides better service than the conventional node B. In a next-generation wireless communication system (NR system or 5G system), all user traffic is served via a shared channel. Therefore, a scheduling device is required that collects status information such as the UE's buffer status, available transmit power status, and channel status, and this is handled by the NR NB 1c-10. A single NR gNB 1c-10 typically controls multiple cells. Compared to current LTE systems, to achieve ultra-high-speed data transmission, the system has a bandwidth exceeding the existing maximum bandwidth, and uses orthogonal frequency division multiplexing (OFDM) as a radio access technology, with beamforming technology also being incorporated. In addition, it applies adaptive modulation and coding (AMC), which determines the modulation scheme and channel coding rate according to the channel conditions of the terminal. The NR CN 1c-05 performs functions such as mobility support, bearer setup, and quality of service (QoS) setup. The NR CN 1c-05 is a device that handles various control functions as well as mobility management for terminals and is connected to multiple base stations. In addition, the next-generation wireless communication system (NR system or 5G system) also works with the existing LTE system, and the NR CN 1c-05 is connected to the MME 1c-25 via a network interface. The MME 1c-25 is connected to the existing base station eNB 1c-30.

[0062] FIG. 1D is a diagram illustrating a radio protocol structure of a next-generation wireless communication system according to one embodiment of the present disclosure.

[0063] Referring to FIG. 1D, the wireless protocols of the next-generation wireless communication system include NR SDAP (service data adaptation protocol) 1d-01, 1d-45, NR PDCP 1d-05, 1d-40, NR RLC 1d-10, 1d-35, NR MAC 1d-15, 1d-30, and NR PHY 1d-20, 1d-25 in the terminal and the NR base station, respectively.

[0064] The main functions of NR SDAP 1d-01 and 1d-45 include some of the following functions:

[0065] -Transfer of user plane data

[0066] -Mapping function between a QoS flow and a data bearer for both DL and UL

[0067] - Marking QoS flow ID in both DL and UL packets

[0068] - Reflective QoS flow to DRB mapping for the UL SDAP PDUs

[0069] For the NR SDAP layer, the UE uses an RRC message to configure whether to use the NR SDAP layer header or the NR SDAP layer functions for each PDCP layer, bearer, or logical channel. If the SDAP header is configured, the NAS reflective QoS setting 1-bit indicator (NAS reflective QoS) and AS reflective QoS setting 1-bit indicator (AS reflective QoS) in the SDAP header instruct the UE to update or reconfigure mapping information related to the QoS flow and data bearer for the uplink and downlink. The SDAP header includes QoS flow ID information indicating the QoS. The QoS information is used as data processing priority, scheduling information, etc. to support smooth service.

[0070] The main functions of NR PDCP 1d-05 and 1d-40 include some of the following functions:

[0071] -Header compression and decompression: ROHC only

[0072] -Transfer of user data

[0073] - In-sequence delivery of upper layer PDUs

[0074] - Out-of-sequence delivery of upper layer PDUs

[0075] -PDCP PDU reordering for reception

[0076] -Duplicate detection of lower layer SDUs

[0077] -Retransmission of PDCP SDUs

[0078] -Ciphering and deciphering functions

[0079] -Timer-based SDU discard in uplink

[0080] The reordering function of the NR PDCP layer refers to the function of reordering PDCP PDUs received in a lower layer based on the PDCP sequence number (SN) and delivering data to a higher layer in the reordered order. Alternatively, the reordering function of the NR PDCP layer may include a function of immediately delivering data regardless of the procedure, and a function of reordering and recording lost PDCP PDUs. The reordering function of the NR PDCP layer may include a function of reporting the status of lost PDCP PDUs to the transmitting side and a function of requesting retransmission of lost PDCP PDUs.

[0081] The main functions of NR RLC 1d-10, 1d-35 include some of the following functions:

[0082] -Transfer of upper layer PDUs

[0083] - In-sequence delivery of upper layer PDUs

[0084] - Out-of-sequence delivery of upper layer PDUs

[0085] -Error Correction through ARQ

[0086] - Concatenation, segmentation and reassembly of RLC SDUs

[0087] -Re-segmentation of RLC data PDUs

[0088] -Reordering of RLC data PDUs

[0089] -Duplicate detection

[0090] -Protocol error detection

[0091] -RLC SDU deletion function (RLC SDU discard)

[0092] -RLC re-establishment function

[0093] The in-sequence delivery function of the NR RLC layer refers to the function of delivering RLC SDUs received from a lower layer to a higher layer in order, and includes the function of reassembling and delivering an RLC SDU when a single RLC SDU is originally received as several RLC SDUs. The in-sequence delivery function of the NR RLC layer also includes the function of rearranging received RLC PDUs based on the RLC sequence number (SN) or PDCP sequence number (SN), the function of rearranging and recording lost RLC PDUs, and the function of reporting the status of lost RLC PDUs to the sender. The in-sequence delivery function of the NR RLC layer also includes the function of requesting retransmission of lost RLC PDUs, and, if a lost RLC SDU is present, the function of delivering only the RLC SDUs up to the lost RLC SDU to the higher layer in order. The sequential delivery function of the NR RLC layer includes a function to sequentially deliver all RLC SDUs received before a timer expires to the upper layer even if there are lost RLC SDUs, or a function to sequentially deliver all RLC SDUs received up to now to the upper layer even if there are lost RLC SDUs. It also processes RLC PDUs in the order they are received (in the order they arrive, regardless of the sequence number order) and delivers them to the NR PDCP layer out of sequence (out-of-sequence delivery). In the case of segments, it receives buffered or subsequently received segments, reassembles them into a complete RLC PDU, processes them, and delivers them to the NR PDCP layer. The NR RLC layer does not include a concatenation function; the concatenation function is performed in the NR MAC layer or is replaced by the multiplexing function of the NR MAC layer.

[0094] The out-of-sequence delivery function of the NR RLC layer refers to the function of immediately delivering RLC SDUs received from a lower layer to a higher layer regardless of the order. It includes the function of reassembling and delivering an RLC SDU that is originally divided into several RLC SDUs when received, storing the RLC SN or PDCP SN of the received RLC PDU, arranging the order, and recording lost RLC PDUs.

[0095] The NR MAC 1d-15, 1d-30 is connected to various NR RLC layers configured in one terminal, and the main functions of the NR MAC include some of the following functions. -Mapping function between logical channels and transport channels

[0096] -Multiplexing / demultiplexing of MAC SDUs

[0097] -Scheduling information reporting function

[0098] -Error correction through HARQ

[0099] - Priority handling between logical channels of one UE

[0100] Priority handling between UEs by means of dynamic scheduling

[0101] -MBMS service identification function

[0102] -Transport format selection function

[0103] -Padding function

[0104] The NR PHY layers 1d-20 and 1d-25 perform the operations of channel coding and modulating upper layer data to form OFDM symbols and transmitting them over a wireless channel, or demodulating and channel decoding OFDM symbols received over a wireless channel and transmitting them to an upper layer.

[0105] In the next generation wireless communication system, a frequency bandwidth will be significantly wider because a much higher frequency band will be used. However, supporting such a wide bandwidth in terms of terminal implementation requires high implementation complexity and incurs high costs. Therefore, the next generation wireless communication system introduces the concept of a bandwidth part (BWP), in which multiple bandwidth parts (BWPs) are set in one cell (Spcell or Scell), and data is transmitted and received via one or multiple bandwidth parts according to instructions from the base station.

[0106] In the present disclosure, when a dormant partial bandwidth according to an embodiment is introduced, a specific operation of a state transition method or a partial bandwidth switching method is implemented taking into consideration the state of an Scell ​​and a plurality of partial bandwidths set in the Scell. Also, in the present disclosure, a state transition method or a partial bandwidth switching method is proposed by managing the dormant mode in partial bandwidth units (BWP-level), and a specific partial bandwidth operation is proposed depending on the state of each SCell or the state or mode (activated, deactivated, or dormant) of each partial bandwidth.

[0107] According to one embodiment, the present disclosure proposes a method for configuring primary channel measurement configuration information for a cell or a partial bandwidth by an RRC message or a MAC CE, and instructing a terminal to apply and use (activate) the primary channel measurement configuration information for the cell or the partial bandwidth by the RRC message or the MAC CE, in order to quickly activate the cell (SCell) or the partial bandwidth. As a result, the present disclosure proposes a method for enabling a terminal to quickly measure a channel signal (e.g., a reference signal) related to the cell or the partial bandwidth and quickly report the measurement result to a base station, thereby quickly activating the cell or the partial bandwidth.

[0108] According to one embodiment, activating a cell or a partial bandwidth refers to a procedure in which a terminal monitors a PDCCH in a cell or a partial bandwidth, a procedure in which a base station transmits a PDCCH to a terminal, or a procedure in which a base station transmits downlink data (PDSCH) to a terminal. According to another embodiment, activating a cell or a partial bandwidth refers to a procedure in which a terminal transmits uplink data (PUSCH), a procedure in which a terminal transmits a HARQ ACK or NACK as a measurement result on a PUCCH, or a procedure in which a terminal transmits a sounding reference signal (SRS). Activating a cell or a partial bandwidth refers to a procedure in which a terminal measures a channel measurement signal (synchronization signal block (SSB), channel state information reference signal (CSI-RS), or reference signal (RS)) transmitted by a base station, or a procedure in which a terminal measures a channel measurement signal transmitted by a base station and reports the measurement result.

[0109] According to one embodiment, the first channel measurement configuration information includes configuration information related to a channel measurement signal for a specific terminal (or terminals) in a cell or partial bandwidth, which is transmitted by a base station. For example, the channel measurement configuration information includes a period of the channel measurement signal, the number of times the signal is transmitted, a period in which the signal is transmitted, an offset related to the time in which the signal is transmitted, or a time length between transmitted signals. Alternatively, the channel measurement configuration information includes a list related to a plurality of channel measurement signals to be transmitted, time transmission resources (or frequency transmission resources) indicating the positions of the transmitted signals, transmission resources (time transmission resources or frequency transmission resources) for reporting measurement results, or a period for reporting measurement results.

[0110] According to one embodiment, the first channel measurement configuration information configured by the RRC message includes a plurality of pieces of channel measurement signal information. By indicating one piece of channel measurement signal information or beam configuration information among the plurality of pieces of channel measurement signal information configured by the RRC message, MAC CE, or DCI, the terminal applies or uses the indicated channel measurement signal information or beam configuration information to perform channel measurement or to make a channel measurement report. According to another embodiment, the channel measurement signal information is configured or indicated by the RRC message or MAC CE, and the terminal applies or uses the configured (or indicated) channel measurement signal information to perform channel measurement or to make a channel measurement report.

[0111] According to one embodiment, the first channel measurement configuration information is configured differently for each cell or each partial bandwidth for a plurality of cells or partial bandwidths configured by the RRC message, and includes beam-related configuration information (transmission configuration indication (TCI) state or quasi co-location (QCL)) such as a beam direction, beam number, or beam position to enable the UE to easily measure transmission resources for channel measurement. In addition, the first channel measurement configuration information includes a timing advance (TA) value (or offset value) for synchronizing a downlink signal of the base station or an uplink signal of the base station, a time alignment timer (TAT) for indicating the validity of the TA value, or a timer value (TAT value), thereby enabling the UE to correctly perform channel measurement or channel measurement reporting.

[0112] The first channel measurement configuration information proposed in the present disclosure can be configured only for the downlink partial bandwidth configuration information of each cell. That is, the first channel measurement configuration information proposed in the present disclosure is not configured for the uplink partial bandwidth configuration information of each cell. This is because the terminal can report the measurement result for the channel or cell only after first measuring the downlink channel, and then correctly receive the PDCCH and follow the instruction to the base station.

[0113] The first channel measurement configuration information proposed in the present disclosure is initially deactivated when configured by an RRC message or after handover, and is subsequently activated by MAC control information, DCI information of PDCCH, or an RRC message proposed in the present disclosure. When configured by an RRC message, the initial state must be deactivated so that the base station can easily manage the cell state or channel measurement procedure of the terminal and accurately perform timing related to when and how the terminal performs channel measurement without RRC message processing delay issues.

[0114] According to one embodiment of the present disclosure, a cell (Spcell, Pcell, Pscell, or Scell) is configured with multiple partial bandwidths for each downlink or uplink, and an activated partial bandwidth (active DL or ULB WP), a dormant partial bandwidth (dormant BWP or dormant DL BWP), or an inactive partial bandwidth (inactive or deactivated DL / ULB WP) is configured and operated through partial bandwidth switching. That is, the downlink or uplink partial bandwidth for each cell is transitioned to an active state, and the data transmission rate is increased using a method similar to carrier aggregation technology. In addition, the downlink partial bandwidth is transitioned or switched to a dormant partial bandwidth, and the UE does not monitor the PDCCH for the cell, thereby saving battery power. The UE performs channel measurement for the downlink partial bandwidth and reports the channel measurement result, thereby supporting early activation of the cell or partial bandwidth. The downlink (or uplink) partial bandwidth for each cell is transitioned to an inactive state, thereby saving battery power for the UE. A state transition instruction or a partial bandwidth switching instruction for each partial bandwidth related to each cell is set and indicated by an RRC message, a MAC CE, or DCI (downlink control information) of a PDCCH.

[0115] According to one embodiment, the dormancy partial bandwidth is also extended and applied to dual connectivity technology, for example, to a PSCell of a secondary cell group. According to another embodiment, when the dormancy partial bandwidth is extended to the concept of cell group suspension or cell group deactivation, a terminal configured with dual connectivity technology is instructed to suspend or deactivate one cell group (e.g., a secondary cell group) and suspend data transmission or reception in the instructed cell group, suspend PDCCH monitoring, or perform PDCCH monitoring intermittently based on a very long period, thereby reducing power consumption of the terminal. In addition, the terminal instructed to suspend or deactivate the cell group performs a channel measurement procedure in the cell group instructed to suspend or deactivate the cell group and reports the channel measurement result to the network (e.g., the master cell group or the secondary cell group), thereby supporting early activation of the dual connectivity technology.

[0116] According to one embodiment, for a cell group for which a cell group suspension or deactivation instruction has been issued, the UE performs the above procedure or maintains and stores the cell group configuration information without discarding or releasing it. Furthermore, the UE restores the cell group configuration information in response to a cell group activation instruction or reactivation instruction from the network. For example, the UE may store or maintain the cell group configuration information (e.g., configuration information or bearer configuration information for each PDCP, RLC, or MAC layer) configured in the UE, or the configuration information for each cell.

[0117] However, if a cell group is suspended or deactivated, the terminal suspends the bearer or the RLC bearer of the bearer, or suspends transmission (or data transmission, for example, SCG transmission) in the cell group. If the terminal receives a cell group resume or activation instruction for a cell group for which suspension or deactivation has been instructed, the terminal resumes, restores, or further applies the configuration information of the cell group, and resumes transmission (e.g., SCG transmission) for the bearer, RLC bearer, or cell group. Alternatively, if the terminal receives a cell group resume or activation instruction for a cell group for which suspension or deactivation has been instructed, the terminal resumes data transmission or data reception, resumes PDCCH monitoring, performs channel measurement reporting, or reactivates periodically configured transmission resources.

[0118] When a cell group is stopped or deactivated, stopping a bearer (a bearer using the RLC UM mode or a bearer using the RLC AM mode) means stopping the PDCP layer or the RLC layer (or stopping data transmission, data reception, or data processing), and not transmitting (or receiving) data related to the bearer (or corresponding to a logical channel identifier corresponding to the bearer) in the MAC layer (or not selecting a logical channel identifier as a target in an LCP (logical channel prioritization) procedure). The procedure for stopping the PDCP layer may be applied to embodiments specifically proposed below in this disclosure.

[0119] When a cell group is suspended or deactivated, suspending an RLC bearer (an RLC bearer using RLC UM mode or an RLC bearer using RLC AM mode) means suspending the RLC layer (or suspending data transmission, data reception, or data processing) and not transmitting (or receiving) data related to the bearer (or corresponding to the logical channel identifier corresponding to the bearer) in the MAC layer (or not selecting the logical channel identifier as a target in the logical channel prioritization (LCP) procedure). Suspending an RLC bearer means that the PDCP layer connected to the RLC layer continues to process data. For example, the PDCP layer connected to the suspended RLC bearer processes and transmits data or receives and processes data via another RLC bearer (e.g., an RLC bearer belonging to a cell group (e.g., MCG) different from the cell group (e.g., SCG)).

[0120] When a cell group is stopped or deactivated, stopping transmission (e.g., SCG transmission) for the cell group means that the MAC layer does not transmit (or receive) data related to bearers (bearers using RLC UM mode or bearers using RLC AM mode) belonging to the cell group (or data corresponding to logical channel identifiers corresponding to the bearers) (or does not select logical channel identifiers as targets in the logical channel prioritization (LCP) procedure). However, stopping transmission (e.g., SCG transmission) for the cell group means that data processing or data pre-processing is possible in the PDCP layer or RLC layer. For example, data (or uplink data) from upper layers is not transmitted to the cell group, but data is pre-processed for transmission in the PDCP layer, RLC layer, or MAC layer.

[0121] When a cell group is resumed or activated, resuming a bearer (a bearer using RLC UM mode or a bearer using RLC AM mode) means resuming the PDCP layer or RLC layer (or resuming data transmission, data reception or data processing) and transmitting (or receiving) data related to the bearer (or corresponding to the logical channel identifier corresponding to the bearer) in the MAC layer (or selecting the logical channel identifier as the target in the LCP (logical channel prioritization) procedure).

[0122] When a cell group is resumed or activated, resuming an RLC bearer (an RLC bearer using RLC UM mode or an RLC bearer using RLC AM mode) means resuming the RLC layer (or resuming data transmission, data reception, or data processing) and transmitting (or receiving) data related to the bearer (or corresponding to a logical channel identifier corresponding to the bearer) in the MAC layer (or selecting a logical channel identifier as the target in the logical channel prioritization (LCP) procedure). Resuming an RLC bearer means transmitting data in the PDCP layer connected to the RLC layer or receiving data from the PDCP layer.

[0123] When a cell group is resumed or activated, resuming transmission (e.g., SCG transmission) related to the cell group means transmitting (or receiving) data related to a bearer (a bearer using RLC UM mode or a bearer using RLC AM mode) belonging to the cell group (or corresponding to a logical channel identifier corresponding to the bearer) in the MAC layer (or selecting a logical channel identifier as a target in the logical channel prioritization (LCP) procedure). However, resuming transmission (e.g., SCG transmission) related to the cell group means that data processing or data pre-processing is possible in the PDCP layer or RLC layer. For example, data (or uplink data) from an upper layer is transmitted to the cell group, and data processing is performed in advance for transmission in the PDCP layer, RLC layer, or MAC layer.

[0124] According to another embodiment, when a cell group is discontinued or deactivated, a bearer (or RLC bearer) using the RLC UM mode is discontinued, and the PDCP layer or the RLC layer is discontinued, thereby discontinuing data transmission / reception or data processing. Alternatively, data transmission or data reception is discontinued in the MAC layer. However, for a bearer (or RLC bearer) using the RLC AM mode, transmission related to the cell group is discontinued, and data processing can be continued in the PDCP layer or the RLC layer, or data transmission or data reception is discontinued in the MAC layer. This is because, when the security key is changed, a retransmission (or regeneration) procedure is performed for the RLC AM bearer during the PDCP re-establishment procedure (thus, if the security key is not changed, the data processing speed is reduced. Also, if the security key is changed, no data loss occurs due to the retransmission (or regeneration) procedure). However, since there is no retransmission (or regeneration) procedure for the RLC UM bearer, data loss occurs within the UE if the data processing procedure is performed in advance for the RLC UM bearer (thus, if the security key is not changed, the data processing speed can be reduced. However, if the security key is changed, there is no retransmission (or regeneration) procedure, and all data is discarded during the re-establishment procedure of the PDCP layer and the RLC layer, resulting in data loss). Therefore, different procedures are applied to bearers (or RLC bearers) using the RLC AM mode and bearers (or RLC bearers) using the RLC UM mode. The procedure for canceling the PDCP layer may be applied to the embodiments specifically proposed below in this disclosure.

[0125] The first channel measurement configuration information for an early cell group or cell (SpCell (Pcell or PSCell) or SCell) activation is included in cell group configuration information or cell (SpCell (Pcell or PSCell) or SCell) configuration information, previously configured cell group configuration information or cell (SpCell (Pcell or PSCell) or SCell) configuration information, or a message indicating cell group or cell (SpCell (Pcell or PSCell) or SCell) activation or reactivation (e.g., an RRC message, RRCReconfiguration, MAC control information, or PDCCH downlink control information (DCI)).

[0126] According to one embodiment, the first channel measurement configuration information includes a configuration information of a cell (e.g., PCell, PSCell, or SCell) of the cell group that includes frequent channel measurement signals (e.g., radio resource, temporary reference signal (TRS), synchronization signal block (SSB), channel state information reference signal (CSI-RS), or reference signal (RS)) so that the base station can temporarily transmit many or good channel measurement signals to quickly activate the cell group (or cell) or allow the terminal to perform channel measurement in the cell. The first channel measurement configuration information includes configuration information such as a period related to the frequent channel measurement signal, or transmission resource information to be transmitted (frequency or time transmission resource on which the frequent channel measurement signal is transmitted), interval, number of times (number of times the frequent channel measurement signal is transmitted), timer value (time on which the frequent channel measurement signal is transmitted) or time interval (interval on which the frequent channel measurement signal is transmitted (e.g., offset of time unit (slot, subframe, symbol, etc.))). In addition, the first channel measurement configuration information includes configuration information such as a transmission resource, period, interval, timing, or offset on which the UE should report the measurement result.

[0127] The first channel measurement configuration information shortens the reporting period (or transmission resource) for the terminal to report channel measurement results, or configures transmission resources for channel measurement so that the base station transmits many channel measurement signals (or transmission resources (e.g., radio resources or temporary reference signals (TRS)) frequently) in order to support the terminal in performing fast channel measurements or measuring many signals. The first channel measurement configuration information includes configuration information related to channel measurement signals for a specific terminal (or terminals) in a cell or partial bandwidth. For example, the first channel measurement configuration information includes the period of the channel measurement signals, the number of signals to be transmitted, the period in which the signals are transmitted, an offset related to the time in which the signals are transmitted, or the time length between transmitted signals. Alternatively, the first channel measurement configuration information includes a list of multiple channel measurement signals to be transmitted, time transmission resources (or frequency transmission resources) indicating the positions of the transmitted signals, transmission resources (time transmission resources or frequency transmission resources) for reporting measurement results, or a period for reporting measurement results.

[0128] According to one embodiment, the first channel measurement configuration information is configured differently for each cell or each partial bandwidth for multiple cells or partial bandwidths configured by the RRC message, and is configured together with beam-related configuration information (TCI (transmission configuration indication) state or QCL (quasi co-location)) such as beam direction, beam number, or beam position to help the terminal easily measure transmission resources for measuring channels.

[0129] According to one embodiment, the first channel measurement configuration information configures a timing advance (TA) value (or offset value) for synchronizing a downlink signal or an uplink signal of the base station, a time alignment timer (TAT) for indicating the validity of the TA value, or a timer value (TAT value), thereby enabling the terminal to correctly perform channel measurement or channel measurement reporting. Furthermore, the first channel measurement configuration information configured by an RRC message includes a plurality of pieces of channel measurement signal information. The first channel measurement configuration information indicates one piece of channel measurement signal information or beam configuration information among the plurality of pieces of channel measurement signal information configured by an RRC message, a MAC CE, or a DCI, thereby enabling the terminal to apply or use the indicated channel measurement signal information or beam configuration information to perform channel measurement or channel measurement reporting. The indication method defines a mapping between a bitmap, an index, an identifier, and each piece of configured channel measurement signal information, and performs indication based on the mapping.

[0130] According to another embodiment, the RRC message or MAC CE configures or indicates signal information for channel measurement, so that the terminal applies or utilizes the configured (or indicated) signal information for channel measurement to perform channel measurement or to make a channel measurement report.

[0131] According to an embodiment of the present disclosure, the first channel measurement configuration information is initially deactivated when configured by an RRC message or after handover, and is subsequently activated by MAC control information, DCI information of a PDCCH, or an RRC message proposed in the present disclosure. When configured by an RRC message, the initial state is set to a deactivated state so that the base station can easily manage the cell state or channel measurement procedure of the terminal and accurately perform timing related to when and how the terminal performs channel measurement without delaying processing of the RRC message.

[0132] According to an embodiment of the present disclosure, the first channel measurement configuration information can be configured only for the downlink partial bandwidth configuration information of each cell. That is, according to an embodiment of the present disclosure, the first channel measurement configuration information is not configured for the uplink partial bandwidth configuration information of each cell. This is because, only when a terminal first measures a downlink channel and reports a measurement result for that channel or that cell can the terminal correctly receive a PDCCH and follow instructions from the base station.

[0133] According to one embodiment, a message (e.g., an RRC message, RRCReconfiguration, MAC control information, or downlink control information (DCI) of a PDCCH) indicating activation or reactivation of a cell group or cell (SpCell (Pcell or PSCell) or SCell) includes secondary channel measurement configuration information for measuring signals of a cell (PSCell, PCell, or SCell) of the cell group. The secondary channel measurement configuration information includes general channel measurement configuration information such as a transmission resource, period, time interval, or number of times of a signal for channel measurement, or a transmission resource, period, or time interval for a channel measurement report.

[0134] In the present disclosure, the first channel measurement configuration information or the second channel measurement configuration information of the terminal is applied according to the following conditions, and the channel measurement result is reported to the base station.

[0135] 1> If the UE receives a message (e.g., a PDCCH indicator, MAC control information, or RRC message) to activate (or resume) a cell (PCell, PSCell, or SCell) or cell group (or if the cell group was previously in a deactivated state),

[0136] 2> If the first channel measurement setting information is set in the terminal,

[0137] 3> The terminal determines, based on the first channel measurement configuration information, that the base station will frequently transmit many channel measurement signals, and measures the many or frequent channel measurement signals in accordance with the first channel measurement configuration information temporarily (e.g., until the time interval (e.g., subframe, slot, or symbol) set by the first channel measurement configuration information or for a promised (or predetermined) time interval or time period taking into account an offset (e.g., while a timer is running)), or until a first condition is satisfied. The terminal also reports the measured channel measurement results based on the period or transmission resource set by the first channel measurement configuration information, until the time interval (e.g., subframe, slot, or symbol) set by the first channel measurement configuration information or for a promised (or predetermined) time interval or time period taking into account an offset (e.g., while a timer is running)), or until a first condition is satisfied. By allowing the UE to measure and report frequent channel measurement signals earlier, the UE can activate (or resume) a cell (PCell, SCell, or PSCell) or a cell group earlier, or be instructed of scheduling information earlier. If the second channel measurement configuration information is configured in the UE after the time interval (e.g., subframe, slot, or symbol) configured by the first channel measurement configuration information, or after the promised (or predetermined) time interval or time (e.g., if a timer expires), or after the first condition is satisfied, the application of the first channel measurement configuration information is stopped or released, and the channel measurement signal is measured according to the second channel measurement configuration information. For example, the UE falls back from the first channel measurement configuration information to the second channel measurement information, or applies the second channel measurement information instead of the first channel measurement configuration information. The UE also reports the measured channel measurement results based on the period or transmission resource configured by the second channel measurement configuration information. If the second channel measurement configuration information is not configured, the UE does not perform channel measurement.

[0138] 2> Otherwise (if the first channel measurement setting information is not set in the terminal),

[0139] 3> If the second channel measurement configuration information is configured in the terminal, the terminal measures the channel measurement signal according to the second channel measurement configuration information, and reports the measured channel measurement results according to the period or transmission resource configured by the second channel measurement configuration information. If the second channel measurement configuration information is not configured, the terminal does not perform channel measurement.

[0140] According to one embodiment, in the present disclosure, the first condition is one of the following conditions. In the present disclosure, when a cell is activated, a cell group is activated, or reactivated (or a cell group is activated from an inactive state) under the first condition, or when a terminal in RRC inactive mode reactivates a connection in an RRC connection reactivation procedure, an efficient condition is initiated that prevents the base station from transmitting unnecessarily many or frequent transmission resources. For example, the first channel measurement configuration information is applied, and a channel measurement procedure or a channel measurement report procedure is performed until one of the following conditions is satisfied:

[0141] The first condition is determined to be satisfied when the UE successfully completes a random access procedure (four-phase random access procedure or two-phase random access procedure) in a cell (e.g., PCell, SCell, or PSCell) or in a cell (e.g., PSCell or SCell) of a cell group, when the UE successfully completes the random access procedure and is initially assigned uplink transmission resources, or when the UE is initially instructed on uplink transmission resources.

[0142] For example, more specifically, if the terminal performs a contention-free random access (CFRA) procedure (e.g., if a pre-specified preamble or terminal cell identifier (e.g., C-RNTI) is assigned).

[0143] When the UE transmits a pre-specified preamble to the cell and receives a random access response (RAR) message, or receives a PDCCH indication for the random access response, the random access procedure can be considered to be successfully completed, and therefore the first condition is determined to be satisfied. Alternatively, when the UE receives an uplink transmission resource for the first time after receiving the RAR, the first condition is determined to be satisfied.

[0144] --If the terminal performs a contention-based random access (CBRA) procedure (e.g., if a pre-specified preamble or terminal cell identifier (e.g., C-RNTI) is not assigned)

[0145] If the UE transmits a preamble (e.g., an arbitrary preamble) to a cell, receives a random access response (RAR) message, transmits message 3 (e.g., a handover complete message) using the uplink transmission resources allocated, included, or indicated in the random access response message, and receives a MAC CE (contention resolution MAC CE) indicating contention resolution from the target base station in message 4, or receives uplink transmission resources via a PDCCH corresponding to the UE's C-RNTI, the random access procedure with the target base station can be considered to have been successfully completed, and the UE determines that condition 1 is satisfied. Alternatively, if the size of the uplink transmission resources allocated in the random access response message is sufficient, the UE transmits message 3, and then transmits additional uplink data, the UE determines that it has received uplink transmission resources for the first time, and therefore determines that condition 1 is satisfied. That is, the UE determines that it has received uplink transmission resources for the first time when it receives an RAR, and therefore determines that condition 1 is satisfied.

[0146] 1> If the terminal is configured or instructed to perform a two-step random access procedure,

[0147] 1> Or, if the message does not set or indicate a two-step random access procedure, but the terminal supports the two-step random access procedure in its terminal capabilities, and the cell's system information supports the two-step random access procedure, and the system information broadcasts information for the two-step random access procedure (e.g., random access resources or thresholds for determining whether or not to perform two-step random access), or the terminal receives the system information and the signal strength is better or greater than the threshold value broadcast in the system information, and the terminal performs the two-step random access procedure in the cell.

[0148] 2> When the two-stage random access procedure is successfully completed, the terminal determines that the first condition is satisfied.

[0149] 2> The two-stage random access procedure is specifically performed by one of the contention-based random access (CBRA) method and the contention-free random access (CFRA) method.

[0150] 3> If the terminal performs a CBRA-based two-phase random access procedure,

[0151] 4> The terminal transmits a preamble on a transmission resource for two-stage random access (e.g., a PRACH occasion, a transmission resource configured by the base station via an RRC message, or a transmission resource broadcast in the system information), and transmits data (e.g., an MsgA MAC PDU) on a transmission resource for data transmission (e.g., a PUSCH occasion). The data includes MAC control information (C-RNTI MAC CE) including a terminal identifier (C-RNTI) or an RRC message (RRCReconfigurationComplete message or handover complete message).

[0152] 4> The terminal monitors the PDCCH scrambled by the terminal identifier (C-RNTI) or the first identifier (MsgB-RNTI) derived by the time or frequency at which the preamble was transmitted.

[0153] 4> If the terminal receives a PDCCH scrambled by a terminal identifier, allocates downlink transmission resources by the PDCCH, or receives MAC control information for time timing adjustment (timing advance command dMAC CE) in the downlink transmission resources,

[0154] 5> The terminal determines that it has successfully completed the two-stage random access procedure and that it has satisfied the first condition.

[0155] 4> If the terminal receives a PDCCH scrambled by the first identifier (MsgB-RNTI), allocates a downlink transmission resource using the PDCCH, or receives a fallback random access response for a preamble transmitted by the terminal on the downlink transmission resource (i.e., if the base station receives the preamble but is unable to receive MsgA, a fallback RAR is sent to transmit MsgA on another transmission resource),

[0156] 5> The terminal transmits data (MsgA MAC PDU) on the transmission resource indicated in the random access response for fallback.

[0157] 5> The terminal monitors the PDCCH scrambled by the terminal identifier (C-RNTI).

[0158] 5> If the terminal receives a PDCCH scrambled by a terminal identifier or allocates uplink transmission resources using the PDCCH, the terminal determines that the two-stage random access procedure has been successfully completed and that the first condition has been satisfied.

[0159] 3> If the terminal performs a CFRA-based two-phase random access procedure,

[0160] 4> The terminal transmits a preamble in a transmission resource for two-stage random access (e.g., a PRACH occasion or a transmission resource designated by the base station as an RRC message) and transmits data (e.g., an MsgA MAC PDU) in a transmission resource for data transmission (e.g., a PUSCH occasion). The data includes MAC control information (C-RNTI MAC CE) including a terminal identifier (C-RNTI) or an RRC message (RRCReconfigurationComplete message or handover complete message).

[0161] 4> The terminal monitors the PDCCH scrambled by the terminal identifier (C-RNTI) or the first identifier (MsgB-RNTI) derived by the time or frequency at which the preamble was transmitted.

[0162] 4> If the terminal receives a PDCCH scrambled by a terminal identifier, allocates a downlink transmission resource by a PDCCH, or receives MAC control information (timing advance command MAC CE) for time timing adjustment in a downlink transmission resource,

[0163] 5> The terminal determines that it has successfully completed the two-stage random access procedure and that it has satisfied the first condition.

[0164] 4> If the terminal receives a PDCCH scrambled by the first identifier (MsgB-RNTI), allocates a downlink transmission resource using the PDCCH, or receives a fallback random access response for a preamble transmitted by the terminal in the downlink transmission resource (i.e., if the base station receives the preamble but is unable to receive MsgA, a fallback RAR indicating that MsgA should be transmitted on another transmission resource),

[0165] 5> The terminal determines that it has successfully completed the two-stage random access procedure and that it has satisfied the first condition.

[0166] 5> The terminal transmits data (MsgA MAC PDU) on the transmission resource indicated in the random access response for fallback.

[0167] 1> When starting a random access procedure or transmitting a preamble for the random access procedure, it is determined that the first condition is satisfied.

[0168] 1> Alternatively, if the terminal configures or instructs a two-step random access procedure in the message, the terminal determines that the first condition is satisfied. For example, before starting the two-step random access procedure, the terminal determines that the first condition is satisfied.

[0169] 1> Alternatively, if a two-step random access procedure is configured or indicated to the terminal in the message, and the transmission resource (PUSCH) configured for data transmission in the two-step random access procedure is greater than a first threshold value, or if a timing advance value is included in the RRC message, the terminal determines that the first condition is satisfied. The first threshold value is configured by the base station in an RRC message (e.g., RRCReconfiguration), broadcast in system information, or set according to the amount of data the terminal has to transmit. For example, before starting the two-step random access procedure, the terminal determines that the first condition is satisfied. Alternatively, if a timing advance value is included in the RRC message or if a two-step random access procedure is configured, the terminal does not transmit a preamble and immediately transmits data on the configured transmission resource (e.g., the transmission resource configured in the RRC message, or the transmission resource indicated by the PDCCH when the terminal monitors the PDCCH of the target base station). Therefore, before starting the two-stage random access procedure, when transmitting data, or before transmitting data, the terminal determines that the first condition is satisfied. Alternatively, if the RRC message includes a timing advance value for time timing adjustment or if the two-stage random access procedure is configured, the terminal does not transmit a preamble and immediately transmits data on a configured transmission resource (PUSCH) (e.g., a transmission resource configured by the RRC message, or a transmission resource indicated by the PDCCH when the terminal monitors the PDCCH of the target base station).If the configured transmission resource (PUSCH) (e.g., the transmission resource configured by the RRC message, or the transmission resource indicated by the PDCCH when the terminal monitors the PDCCH of the target base station) is greater than the first threshold value, or if the RRC message includes a timing advance value for time timing adjustment, the terminal determines that the first condition is satisfied before starting the two-stage random access procedure, when transmitting data, or before transmitting data.

[0170] 1> If an RRC INACTIVE mode UE transmits an RRC Resume Request message and then receives an RRC Resume message (or an RRC Setup message) in response thereto, it can be considered that the first condition is satisfied.

[0171] 1> When the terminal performs channel measurement based on the first channel measurement configuration information set by the RRC message, if the timer indicating the period for channel measurement expires,

[0172] 1> When the terminal performs channel measurement based on the first channel measurement configuration information set by the RRC message, if the time interval indicating the period for channel measurement has passed (or expired), or if the time interval has been used (or applied),

[0173] 1> When the terminal performs channel measurement based on the first channel measurement configuration information set by the RRC message, if the terminal measures (or completes) all signals for channel measurement the set number of times, or if the terminal receives signals the set number of times,

[0174] 1> When the terminal performs channel measurement based on the first channel measurement configuration information set by the RRC message, if the terminal completes the channel measurement based on the configuration information (if the channel measurement expires), or if the terminal completes the channel measurement report (or if the channel measurement report expires),

[0175] If the first condition is met, the higher layer (e.g., RRC layer) indicates to the lower layer (e.g., PDCP layer, RLC layer, MAC layer, or PHY layer) with an indicator, or the lower layer (e.g., PDCP layer, RLC layer, MAC layer, or PHY layer) indicates to the higher layer (e.g., RRC layer).

[0176] The method of configuring or applying first channel measurement configuration information according to one embodiment of the present disclosure is extended and configured and used when activating or resuming a cell group (e.g., a PSCell), activating an SCell, resuming an RRC connection in an RRC inactive mode (e.g., when using an RRCResume message), or performing a handover procedure (e.g., when using an RRCReconfiguration message).

[0177] In this disclosure, fractional bandwidth (BWP) is used interchangeably for uplink and downlink, and the meaning refers to uplink fractional bandwidth and downlink fractional bandwidth, respectively, depending on the context.

[0178] In this disclosure, the term "link" is used interchangeably to refer to an upward link and a downward link, and the meanings thereof refer to upward links and downward links, respectively, depending on the context.

[0179] In the present disclosure, a cell refers to a PCell, an SCell (e.g., an SCell configured in a master cell group (MCG)), a PSCell (e.g., a PCell in a secondary cell group (SCG)), or an SCell (e.g., an SCell configured in a secondary cell group (SCG)). In the present disclosure, a dormant BWP is configured or introduced for an SCell or PSCell of a UE performing a carrier aggregation technology or a dual connectivity technology, and the PDCCH is not monitored in the dormant BWP, thereby reducing battery consumption of the UE. In addition, in the present disclosure, channel measurement is performed and reported (e.g., measurement or reporting of channel state information (CSI) or channel quality information (CQI)), or beam measurement, beam tracking, or beam operation is performed in the dormant BWP. When data transmission is required, switching or activation is performed in the normal BWP, so that data transmission can begin quickly in the normal BWP. The dormant partial bandwidth is configured or not applied to an SpCell (PCell of an MCG, or PCell (or PSCell) of an SCG) that must continuously monitor signals, transmit or receive feedback, or check and maintain synchronization, or an SCell with a PUCCH configured.

[0180] If the UE is instructed to switch or activate an SCell of the master cell group in a dormant partial bandwidth via the PCell, the UE reports the channel measurement results measured by performing a channel measurement procedure for the dormant partial bandwidth of the SCell in the transmission resources of the PCell of the master cell group (MCG) (e.g., via the PUCCH (physical uplink control channel) transmission resources of the PCell) or in the transmission resources of the SCell in which the PUCCH of the master cell group is configured (e.g., via the PUCCH (physical uplink control channel) transmission resources). Which cell or partial bandwidth of which cell the channel measurement results related to should be reported in which transmission resources (e.g., PUCCH or PUSCH) is configured for each cell or partial bandwidth in the UE in an RRC message.

[0181] If the UE is instructed to switch or activate an SCell of a secondary cell group in a dormant partial bandwidth via a PSCell, the UE reports the channel measurement results measured by performing a channel measurement procedure for the dormant partial bandwidth of the SCell in the transmission resources of the PSCell of the secondary cell group (SCG) (e.g., via the PUCCH (physical uplink control channel) transmission resources of the PSCell) or in the transmission resources of the SCell in which the PUCCH of the secondary cell group is configured (e.g., via the PUCCH (physical uplink control channel) transmission resources). Which cell or partial bandwidth of which cell the channel measurement results related to should be reported in which transmission resources (e.g., PUCCH or PUSCH) is configured for each cell or partial bandwidth in the UE in an RRC message.

[0182] If a terminal is instructed via the PCell to switch or activate a PSCell or SCell of a secondary cell group in a dormant partial bandwidth, or to suspend a cell group (SCG or PSCell) in a secondary cell group (SCG or PSCell), the terminal reports the channel measurement results measured by performing a channel measurement procedure for the partial bandwidth of the PSCell or SCell (the partial bandwidth configured by the RRC message or the last activated partial bandwidth) or the dormant partial bandwidth in the transmission resources of the PCell of the master cell group (MCG) (e.g., via the PUCCH (physical uplink control channel) transmission resources of the PCell), the transmission resources of the SCell in which the PUCCH of the master cell group is configured (e.g., via the PUCCH (physical uplink control channel) transmission resources), or the transmission resources of the PSCell of the secondary cell group (SCG) (e.g., via the PUCCH (physical uplink control channel) transmission resources of the PSCell). The channel measurement results relating to which cell or partial bandwidth of which cell are to be reported in which transmission resource (e.g., PUCCH or PUSCH) of which cell are configured for each cell or partial bandwidth in the terminal in an RRC message.

[0183] In the present disclosure, several embodiments are proposed that operate on a PDCCH DCI basis, a MAC CE basis or an RRC message basis to operate a dormant partial bandwidth or a cell group suspension state for a terminal's SCell (SCell of a master cell group when carrier aggregation technology is configured, or SCell of a secondary cell group when dual connectivity technology is configured) or PSCell (PCell of a secondary cell group when dual connectivity technology is configured).

[0184] A network or a base station configures an Spcell (Pcell and PScell) and multiple Scells for a terminal. The Spcell refers to a Pcell when the terminal communicates with one base station, and refers to a Pcell of the master base station or a PScell ​​of the secondary base station when the terminal communicates with two base stations (a master base station and a secondary base station). A Pcell or a Pscell refers to a primary cell used when a terminal and a base station communicate in the MAC layer, and refers to a cell that adjusts timing for synchronization, performs random access, transmits HARQ ACK / NACK feedback in PUCCH transmission resources, and exchanges most control signals. A technology in which a base station operates multiple Scells together with an Spcell to increase transmission resources and improve uplink or downlink data transmission resources is called a carrier aggregation technology or a dual connectivity technology.

[0185] In the present disclosure, PCell means MCG (master cell group), and PSCell means SCG (secondary cell group). Also, MCG means including PCell and SCell configured in MCG, and SCG means including PSCell and SCell configured in SCG. Also, cell indicates a cell group, or cell group indicates a cell.

[0186] When an Spcell and multiple Scells are configured in a UE by an RRC message, the state or mode of each cell (PCell, PSCell, or SCell), or for a partial bandwidth of each Scell ​​or each SCell, or for a cell group is configured by an RRC message, a MAC CE, or DCI of a PDCCH. The state or mode of a cell is set to an active mode or activated state, or a deactivated mode or deactivated state.

[0187] According to one embodiment, a cell being in an active mode or an active state means that a terminal, in a cell in the active mode or an active state, can exchange uplink or downlink data with a base station in a partial bandwidth other than an activated partial bandwidth, an activated general partial bandwidth, or an activated dormant partial bandwidth of the cell, and can monitor a PDCCH to confirm an instruction from the base station. Alternatively, a cell being in the active mode or an active state means that a terminal performs channel measurement on a downlink of a cell in the active mode or an active state (or a partial bandwidth other than an activated partial bandwidth, an activated general partial bandwidth, or an activated dormant partial bandwidth of the cell), periodically reports the measurement information to the base station, and periodically transmits a sounding reference signal (SRS) to the base station so that the base station can perform uplink channel measurement. Alternatively, the terminal activates or switches a partial bandwidth to a dormant partial bandwidth for an activated cell according to the instruction of the base station (e.g., PDCCH, MAC CE, or RRC message), and if the dormant partial bandwidth is activated in an activated cell, the terminal does not perform PDCCH monitoring in the cell, but performs a channel measurement report and performs a procedure to report the channel measurement results.

[0188] According to an embodiment, if the activated cell of the dormant partial bandwidth is an SCell, the UE does not monitor the PDCCH, does not receive downlink data, or performs channel measurement or measurement result reporting. Alternatively, the UE suspends a configured periodic transmission resource (e.g., a first-type periodic transmission resource (configured uplink grant type 1)), or clears or initializes a configured periodic transmission resource (e.g., a second-type periodic transmission resource (configured uplink grant type 2)). Alternatively, the UE does not transmit a sounding reference signal (SRS), does not transmit uplink data, or does not transmit a PUCCH (e.g., a scheduling request (SR) or a preamble for random access).

[0189] However, if the dormant partial bandwidth is activated or the cell for which cell group suspension is instructed is a PSCell, the UE does not monitor the PDCCH, performs PDCCH monitoring at a very long period, or does not receive downlink data, or performs channel measurement or measurement result reporting, or suspends a configured periodic transmission resource (e.g., a first-type periodic transmission resource (configured uplink grant type 1)), or clears or initializes a configured periodic transmission resource (e.g., a second-type periodic transmission resource (configured uplink grant type 2)), or transmits a sounding reference signal (SRS), does not transmit uplink data, transmits a PUCCH (e.g., a scheduling request (SR) or a preamble for random access), or performs a random access procedure.

[0190] According to an embodiment, if the cell activated as a partial bandwidth other than the dormant partial bandwidth is an SCell, the UE performs PDCCH monitoring, receives downlink data, or performs channel measurement or measurement result reporting. Alternatively, the UE resumes a configured periodic transmission resource (e.g., a first-type periodic transmission resource (configured uplink grant type 1)), or configures or activates a configured periodic transmission resource (e.g., a second-type periodic transmission resource (configured uplink grant type 2)). Alternatively, the UE transmits a sounding reference signal (SRS), transmits uplink data, transmits a PUCCH (e.g., a scheduling request (SR) or a preamble for random access), or performs a random access procedure.

[0191] According to an embodiment, if a partial bandwidth other than a dormant partial bandwidth is activated or the cell for which cell group resumption (SCG resumption) is indicated is a PSCell, the UE performs PDCCH monitoring, receives downlink data, or performs channel measurement or measurement result reporting. Alternatively, the UE resumes a configured periodic transmission resource (e.g., a first-type periodic transmission resource (configured uplink grant type 1)), or configures or activates a configured periodic transmission resource (e.g., a second-type periodic transmission resource (configured uplink grant type 2)). Alternatively, the UE transmits a sounding reference signal (SRS), transmits uplink data, transmits a PUCCH (e.g., a scheduling request (SR) or a preamble for random access), or performs a random access procedure.

[0192] However, a cell being in an inactive mode or in an inactive state means that the terminal cannot exchange data with the base station because the partial bandwidth set for the cell is in an inactive state, the set partial bandwidth is not activated, or there is no activated partial bandwidth in the set partial bandwidth. Alternatively, a cell being in an inactive mode or in an inactive state means that the terminal does not monitor the PDCCH to confirm the base station's instruction, does not perform channel measurement, does not perform measurement report, and does not transmit a pilot signal.

[0193] Therefore, to activate a cell in a deactivated mode, the base station first configures frequency measurement configuration information in the terminal using an RRC message, and the terminal performs cell or frequency measurement based on the frequency measurement configuration information. After receiving a cell or frequency measurement report from the terminal, the base station activates the deactivated cell based on the frequency / channel measurement information. This causes a significant delay in the base station activating the carrier aggregation technology or dual connectivity technology in the terminal and starting data transmission or data reception.

[0194] In the present disclosure, a dormant BWP or a dormant state is proposed for a partial bandwidth of each activated cell (e.g., an activated SCell or an activated PS Cell) to conserve battery power of a UE and enable early start of data transmission or data reception, and a dormant BWP (bandwidth part) is proposed to be set or introduced for each activated cell. Alternatively, in the present disclosure, when a dual connectivity technology is configured in a UE, a cell group state is proposed to be set or introduced as an activated state, a dormant state, a suspended state, or a deactivated state or a resumed state for each cell group, and a method for performing a cell group suspension (SCG suspension) or cell group resumption (SCG resumption) instruction instructing a cell group state transition, and a UE operation therefor are proposed.

[0195] In a partial bandwidth or dormant partial bandwidth (dormant BWP inactivated SCell) that is a dormant mode of an activated cell, or when the dormant partial bandwidth is activated, the terminal cannot exchange data with the base station, does not monitor the PDCCH to confirm the base station's instructions, or does not transmit a pilot signal, but performs channel measurement and reports the measurement results related to the measured frequency / cell / channel periodically or when an event occurs, according to the base station configuration. Therefore, because the terminal does not monitor the PDCCH or transmit a pilot signal in the dormant partial bandwidth (dormant BWP) of an activated cell, battery consumption is reduced compared to the general partial bandwidth (or a partial bandwidth that is not the dormant partial bandwidth) of an activated cell, or compared to when the general partial bandwidth (or a partial bandwidth that is not the dormant partial bandwidth) of an activated cell is activated. In addition, unlike when a cell is deactivated, in order to perform a channel measurement report, the base station can activate the general partial bandwidth of the activated cell earlier based on the measurement report or based on the measurement report of the dormant partial bandwidth of the activated cell, thereby allowing carrier aggregation technology to be used earlier and reducing transmission delay.

[0196] Therefore, in the present disclosure, a cell being in an active mode or an active state means that a terminal can exchange uplink or downlink data with a base station in an active mode or an active cell in a partial bandwidth other than the activated partial bandwidth, activated general partial bandwidth, or activated dormant partial bandwidth of the cell, monitor the PDCCH to confirm the base station's instructions, perform channel measurements for the downlink of a cell in an active mode or an active state (or a partial bandwidth other than the activated partial bandwidth, activated general partial bandwidth, or activated dormant partial bandwidth of the cell), periodically report the measurement information to the base station, and periodically transmit a pilot signal (SRS: Sounding Reference Signal) to the base station so that the base station can perform uplink channel measurements. Furthermore, in the present disclosure, a cell being in an active mode or an active state means that a terminal, in an active mode or an activated cell, cannot exchange uplink or downlink data with a base station in the activated dormant partial bandwidth of the cell, or does not monitor the PDCCH to confirm the base station's instructions, but can perform channel measurements on the downlink of the activated dormant partial bandwidth of a cell in an active mode or an activated state, and periodically report the measurement information to the base station.

[0197] According to an embodiment, if the dormant partial bandwidth is activated or the cell for which cell group suspension is instructed is a PSCell, the UE does not monitor the PDCCH, performs PDCCH monitoring at a very long period, or does not receive downlink data. Alternatively, the UE performs channel measurement or measurement result reporting, suspends configured periodic transmission resources (e.g., type 1 periodic transmission resources (configured uplink grant type 1)), or clears or initializes configured periodic transmission resources (e.g., type 2 periodic transmission resources (configured uplink grant type 2)). Alternatively, the UE transmits a sounding reference signal (SRS), does not transmit uplink data, transmits a PUCCH (e.g., a scheduling request (SR) or a preamble for random access), or performs a random access procedure.

[0198] According to an embodiment, if the cell for which cell group deactivation (or suspension) is instructed is a PSCell (or SCG), the UE does not monitor the PDCCH, performs PDCCH monitoring at a very long period, or does not receive downlink data. Alternatively, the UE performs channel measurement or measurement result reporting, suspends configured periodic transmission resources (e.g., type 1 periodic transmission resources (configured uplink grant type 1)), or clears or initializes configured periodic transmission resources (e.g., type 2 periodic transmission resources (configured uplink grant type 2)). Alternatively, the UE transmits a sounding reference signal (SRS), does not transmit uplink data, transmits a PUCCH (e.g., a scheduling request (SR) or a preamble for random access), or performs a random access procedure. However, when cell group deactivation (or suspension) is instructed, a frequency measurement procedure (radio resource management) may be performed based on frequency measurement configuration information configured by the base station using the RRC message instructing cell group deactivation (or suspension). Alternatively, when radio link monitoring (RLM) configuration information is configured, if an indication that signal synchronization is not achieved is received from the RLM procedure (lower layer (PHY layer)) based on timer T310, timer T310 is activated, and if timer T310 expires, a radio connection failure is declared. If an indication that signal synchronization is achieved is received, the running timer T310 is stopped. Also, when cell group deactivation (or suspension) is instructed, if beam-related configuration information is configured to perform a beam failure detection procedure using the RRC message instructing cell group deactivation (or suspension), the UE performs the beam failure detection procedure.

[0199] According to one embodiment, in the present disclosure, the term "dormant bandwidth sub-bandwidth" refers to the state of a sub-bandwidth or is used as a name of a logical concept indicating a specific sub-bandwidth. Therefore, the dormant bandwidth sub-bandwidth may be activated, deactivated, or switched. For example, an instruction to switch an activated sub-bandwidth in a cell to a dormant bandwidth sub-bandwidth, an instruction to put a cell into a dormant mode, or an instruction to activate a dormant bandwidth sub-bandwidth in a cell are all interpreted as having the same meaning.

[0200] According to one embodiment, in the present disclosure, a general partial bandwidth refers to a partial bandwidth other than a dormant partial bandwidth among partial bandwidths set for each cell of a terminal by an RRC message. In the general partial bandwidth, the terminal can exchange uplink or downlink data with a base station, monitor a PDCCH to confirm instructions from the base station, perform downlink channel measurements, periodically report measurement information to the base station, and periodically transmit a pilot signal (SRS: Sounding Reference Signal) to the base station so that the base station can perform uplink channel measurements. In addition, the general partial bandwidth refers to an initial activated partial bandwidth, a basic partial bandwidth, or an initial activated partial bandwidth or initial partial bandwidth activated from dormancy.

[0201] According to one embodiment, only one dormant bandwidth sub-bandwidth is set for the downlink in the sub-bandwidths set for each cell of the terminal, or one dormant bandwidth sub-bandwidth is set for the uplink or downlink in the sub-bandwidths set for each cell of the terminal.

[0202] According to one embodiment, in the present disclosure, the state of a cell group is set to an activated state, a suspended state, or a deactivated state. The state of a cell group is indicated by a bitmap or an indicator of DCI in a PDCCH, by MAC control information, or by an indicator in an RRC message. If the state of a cell group is indicated as an activated state, the configuration information of the cell group configured or indicated by an RRC message (e.g., an RRCReconfiguration message, an RRCSetup message, or an RRCResume message) is saved and applied, restored, or resumed in the terminal. In addition, the terminal monitors the PDCCH, receives downlink data, or performs channel measurement or measurement result reporting in the PCell, PSCell, or configured SCell of the cell group in accordance with the configuration of the RRC message. Alternatively, the UE resumes a configured periodic transmission resource (e.g., a first-type periodic transmission resource (configured uplink grant type 1)), or configures or activates a configured periodic transmission resource (e.g., a second-type periodic transmission resource (configured uplink grant type 2)). Alternatively, the UE transmits a sounding reference signal (SRS), transmits uplink data, transmits a PUCCH (e.g., a scheduling request (SR) or a preamble for random access), or performs a random access procedure.

[0203] According to an embodiment, when the state of a cell group is indicated as a suspended state or a deactivated state, the UE does not store or discard configuration information of the cell group configured or indicated by an RRC message (e.g., an RRCReconfiguration message, an RRCSetup message, or an RRCResume message), but stops applying it. Furthermore, the UE monitors a PDCCH, receives downlink data, or performs channel measurement or measurement result reporting in a PCell, PSCell, or configured SCell of the cell group, as configured by the RRC message. Alternatively, the UE resumes a configured periodic transmission resource (e.g., a first-type periodic transmission resource (configured uplink grant type 1)), or configures or activates a configured periodic transmission resource (e.g., a second-type periodic transmission resource (configured uplink grant type 2)). Alternatively, the terminal may transmit a sounding reference signal (SRS), transmit uplink data, transmit a PUCCH (e.g., a scheduling request (SR) or a preamble for random access), or perform a random access procedure.

[0204] According to one embodiment, if the state of a cell group is indicated as a deactivated state or if the release of cell group configuration information is indicated, the terminal releases or discards the configuration information of the cell group configured or indicated by an RRC message (e.g., an RRCReconfiguration message, an RRCSetup message, or an RRCResume message).

[0205] FIG. 1E is a diagram illustrating a procedure for efficiently using a fairly wide frequency bandwidth to serve terminals in a next-generation wireless communication system according to one embodiment of the present disclosure.

[0206] FIG. 1E illustrates how next generation wireless communication systems will efficiently use significantly wider frequency bandwidths, serve a variety of different capability or category terminals, and conserve battery life.

[0207] A cell provided by a base station covers a very wide frequency band, such as 1e-05. However, in order to provide services to terminals with different capabilities, the wide frequency band is divided into multiple partial bandwidths, which are managed by a single cell.

[0208] First, when a terminal is initially powered on, it searches the entire frequency band provided by the operator (PLMN) in units of a certain resource block (e.g., 12 resource blocks (RBs)). That is, the terminal begins searching for a primary synchronization sequence (PSS) / secondary synchronization sequence (SSS) in the entire system bandwidth in units of resource blocks (1e-10). If the terminal searches for a PSS / SSS (1e-01 or 1e-02) in units of resource blocks and detects a signal, it reads and interprets (decodes) the signal to confirm the boundary between the subframe and the radio frame. Therefore, subframes are distinguished in 1 ms units, and downlink signals are synchronized with the base station. A resource block (RB) is defined as a two-dimensional unit that is the size of a given frequency resource and a given time resource. For example, a 1 ms unit is defined for time resources, and 12 subcarriers (1 carrier x 15 kHz = 180 kHz) are defined for frequency resources. After completing synchronization, the UE checks the master system information block (MIB) or minimum system information (MSI), checks control resource set (CORESEST) information, and checks initial access bandwidth part (BWP) information (1e-15, 1e-20). CORESET information refers to the location of time / frequency transmission resources from which a control signal is transmitted from a base station, for example, indicating the location of resources from which a PDCCH channel is transmitted. That is, CORESET information indicates where first system information (SIB1: system information block 1) is transmitted, and indicates in which frequency / time resource the PDCCH is transmitted. When the UE reads the first system information, it checks information related to the initial BWP.When the UE completes synchronization of the downlink signal with the base station and receives a control signal, it performs a random access procedure in the initial partial bandwidth (initial BWP) of the cell on which the UE is camped, requests RRC connection establishment, receives an RRC message, and performs RRC connection establishment.

[0209] In RRC connection setup, multiple partial bandwidths are configured for each cell (Pcell, Pscell, Spcell, or Scell). In one cell, multiple partial bandwidths are configured for the downlink, and multiple partial bandwidths are configured for the uplink separately.

[0210] The multiple partial bandwidths are set as indicated by a partial bandwidth identifier (BWP identifier) ​​to be used as an initial partial bandwidth (initial BWP), a default partial bandwidth (default BWP), a first active partial bandwidth (first active BWP), a dormant partial bandwidth (dormant BWP), or a first active partial bandwidth (first active BWP from dormant) activated from a dormant state.

[0211] The initial partial bandwidth (initial BWP) is used in a cell-specific partial bandwidth defined for each cell. A terminal connecting to a cell for the first time establishes a connection to the cell through a random access procedure, or a terminal that has established a connection can synchronize with the initial partial bandwidth. The base station configures an initial downlink partial bandwidth (initial downlink BWP) to be used in the downlink and an initial uplink partial bandwidth (initial uplink BWP) to be used in the uplink, for each cell. Configuration information related to the initial partial bandwidth is broadcast in the first system information (SIB1) indicated by CORESET, and the base station further configures the initial partial bandwidth in the terminal that has established a connection through an RRC message. The initial partial bandwidth is designated as partial bandwidth identifier 0 in the uplink and downlink, respectively. That is, all terminals connected to the same cell use the same initial partial bandwidth designated as partial bandwidth identifier 0. This is because it has the advantage of facilitating the contention-based random access procedure by allowing the base station to transmit a random access response (RAR) message in an initial partial bandwidth that can be read by all terminals when performing the random access procedure.

[0212] The first active BWP is configured to be different for each UE (UE specific) and is designated as a partial bandwidth identifier in multiple partial bandwidths. The first active BWP is configured for each downlink and uplink and is configured as a partial bandwidth identifier in the first active downlink BWP and the first active uplink BWP. The first active BWP is used to indicate which partial bandwidth is to be activated and used first when multiple partial bandwidths are configured in one cell. For example, when a Pcell or Pscell and multiple Scells are configured in a UE and multiple partial bandwidths are configured in each Pcell, Pscell, or Scell, if the Pcell, Pscell, or Scell ​​is activated, the UE activates and uses the first active BWP in the multiple partial bandwidths configured in the Pcell, Pscell, or Scell. That is, for the downlink, the first active downlink BWP is activated and used, and for the uplink, the first active uplink BWP is activated and used.

[0213] The operation of a terminal for a cell to switch the current or activated downlink partial bandwidth and activate the first activated downlink partial bandwidth (or the partial bandwidth set or indicated by an RRC message) or to switch the current or activated uplink partial bandwidth and activate the first activated uplink partial bandwidth (or the partial bandwidth set or indicated by an RRC message) is performed when the cell or partial bandwidth is in an inactive state and an instruction to activate it is received via an RRC message, MAC control information, or DCI. Also, the operation is performed when an instruction to transition the cell or partial bandwidth to a dormant state or an instruction to activate a dormant partial bandwidth is received via an RRC message, MAC control information, or DCI. This is because, when activating a cell or a partial bandwidth, the current or activated downlink partial bandwidth is switched and the first activated downlink partial bandwidth (or the partial bandwidth set or indicated by an RRC message) is activated, or the uplink partial bandwidth is switched and the first activated uplink partial bandwidth (or the partial bandwidth set or indicated by an RRC message) is activated. Therefore, even when performing a channel measurement report in a dormant state, the base station can effectively use the carrier aggregation technology only by measuring and reporting the frequency / channel for the first activated downlink / uplink partial bandwidth. A default partial bandwidth (default BWP) is set differently for each UE (UE specific) and is designated and indicated as a partial bandwidth identifier in multiple partial bandwidths. The default partial bandwidth is set only for the downlink. The default partial bandwidth is used as a partial bandwidth to which activated partial bandwidths in multiple downlink partial bandwidths fall back after a certain period of time.For example, a partial bandwidth inactivity timer (BWP inactivity timer) is set per cell or per partial bandwidth via an RRC message, and the timer is started or restarted when data transmission / reception occurs in an activated partial bandwidth other than the basic partial bandwidth, or when an activated partial bandwidth is switched to another partial bandwidth. If the timer expires, the UE falls back or switches the activated downlink partial bandwidth to the basic bandwidth in the cell. Switching refers to a procedure of deactivating the currently activated partial bandwidth and activating the partial bandwidth for which switching is indicated. Switching is triggered by an RRC message, MAC control element, or downlink control information (DCI) of L1 signaling (PDCCH). Switching is triggered by indicating the partial bandwidth to be switched to or activated, and the partial bandwidth is indicated by a partial bandwidth identifier (e.g., 0, 1, 2, 3, or 4).

[0214] The reason why the basic partial bandwidth is applied and used only for the downlink is that the base station can facilitate base station scheduling by allowing the terminal to fall back to the basic partial bandwidth after a certain period of time for each cell and receiving an instruction from the base station (e.g., DCI of the PDCCH). For example, if the base station sets the basic partial bandwidth of a terminal connected to a cell as the initial partial bandwidth, the base station will continue to instruct scheduling using only the initial partial bandwidth after a certain period of time. If the basic partial bandwidth is not set by an RRC message, the initial partial bandwidth is considered to be the basic partial bandwidth, and the basic partial bandwidth falls back to the initial partial bandwidth when the partial bandwidth deactivation timer expires.

[0215] Alternatively, in order to increase the flexibility of the base station implementation, a basic partial bandwidth is defined and set for the uplink as well, and is used in the same manner as the basic partial bandwidth for the downlink.

[0216] A dormant partial bandwidth (dormant BWP) refers to a partial bandwidth that is a dormant mode of an activated cell or a dormant partial bandwidth (dormant BWP inactivated SCell). When a dormant partial bandwidth is activated, the terminal cannot exchange data with the base station, does not monitor the PDCCH to confirm the base station's instructions, or does not transmit a pilot signal, but performs channel measurement and reports the measurement results related to the measured frequency / cell / channel periodically or when an event occurs according to the base station settings. Therefore, since the terminal does not monitor the PDCCH or transmit a pilot signal in the dormant partial bandwidth (dormant BWP) of an activated cell, it can save battery power compared to the general partial bandwidth (or a partial bandwidth that is not the dormant partial bandwidth) of an activated cell, or compared to when the general partial bandwidth (or a partial bandwidth that is not the dormant partial bandwidth) of an activated cell is activated, and unlike when the cell is deactivated, the base station can activate the general partial bandwidth of the activated cell earlier based on the measurement report or the measurement report of the dormant partial bandwidth of the activated cell, allowing the base station to use carrier aggregation technology earlier and reduce transmission delay.

[0217] The first activated partial bandwidth (or the first activated non-dormant partial bandwidth or the partial bandwidth set or indicated by an RRC message) activated after switching from a dormant state or a dormant partial bandwidth is the DCIMAC of the PDCCH when the terminal operates the partial bandwidth of one activated cell in the dormant partial bandwidth, when the activated partial bandwidth in the activated cell is the dormant partial bandwidth, or when switching to the dormant partial bandwidth in the cell. When a CE or RRC message is used to instruct the terminal to switch the partial bandwidth of an activated cell to a general partial bandwidth (or a partial bandwidth that is not a dormant partial bandwidth) in a dormant partial bandwidth, when a dormant partial bandwidth is used to instruct the terminal to switch or convert an activated partial bandwidth to a general partial bandwidth, or when a dormant partial bandwidth is used to instruct the terminal to switch or convert or activate an activated partial bandwidth to a general partial bandwidth (e.g., the first activated partial bandwidth activated from dormancy), this is the partial bandwidth to which the terminal must switch and activate the current or activated partial bandwidth of the activated cell, or the partial bandwidth to be activated from a dormant state set by the RRC message.

[0218] Figure 1F is a diagram showing a procedure for a terminal to convert from an RRC idle mode to an RRC connected mode in a next-generation wireless communication system according to one embodiment of the present disclosure, and showing a procedure for configuring bearer configuration information, cell group configuration information, cell configuration information, or channel measurement configuration information for connection in the terminal.

[0219] A cell served by a base station covers a fairly wide frequency band. First, the terminal searches the entire frequency band provided by the operator (PLMN) in units of a certain resource block (e.g., 12 resource blocks (RBs)). That is, the terminal begins searching for a primary synchronization sequence (PSS) / secondary synchronization sequence (SSS) in the entire system bandwidth in units of resource blocks. If the terminal searches for a PSS / SSS signal in units of resource blocks and detects it, it reads and interprets (decodes) the signal and checks the boundaries between subframes and radio frames. Once the terminal completes synchronization, it reads the system information of the cell it is currently camped on. That is, it checks the master system information block (MIB) or minimum system information (MSI), checks the control resource set (CORESEST) information, reads the system information, and checks the initial bandwidth part (BWP) information (1f-01, 1f-05). The CORESET information refers to the location of a time / frequency transmission resource where a control signal is transmitted from a base station, for example, the location of a resource where a PDCCH channel is transmitted.

[0220] When the terminal completes synchronization of the downlink signal with the base station and receives a control signal, the terminal performs a random access procedure in the initial partial bandwidth, receives a random access response, requests RRC connection establishment, receives an RRC message, and performs RRC connection establishment (1f-10, 1f-15, 1f-20, 1f-25, 1f-30).

[0221] After completing the basic RRC connection setup, the base station transmits an RRC message (UECapabilityEnquiry) (1f-35) to the UE to inquire about the UE capabilities (UE capability). Alternatively, the base station can inquire about the UE capabilities from the MME or AMF to confirm the UE capabilities. This is because the MME or AMF stores the UE capability information when the UE is previously connected to the base station. If the UE capability information desired by the base station is not stored, the base station requests the UE capabilities from the UE. When reporting the UE capabilities, the UE reports to the base station, as UE capabilities, whether the UE supports a dormant partial bandwidth for an SCell of each cell group (master cell group or secondary cell group), whether the UE supports the first, second, third, or fourth embodiment of the present disclosure, whether the UE supports a dormant partial bandwidth for a PSCell of each cell group, whether the UE supports a cell group suspension or resumption procedure for a PSCell of each cell group, or the number of supported cell groups. In addition, in the RRC connection resumption procedure, the terminal uses the RRCResume message to report to the base station as terminal capabilities whether it can store and restore, discard, partially reconfigure, or activate the configuration information of the SCell of the master cell group, the SCell of the secondary cell group, or the PSCell of the secondary cell group.

[0222] The base station transmits an RRC message to the terminal to check its capabilities, for example, to determine the frequency band the terminal can read or the range of the frequency band that can be read. After checking the terminal's capabilities, the base station configures an appropriate bandwidth partition (BWP) for the terminal. When the terminal receives an RRC message inquiring about its capabilities, the terminal responds by indicating the bandwidth range supported by the terminal or the range of the bandwidth supported within the current system bandwidth by using an offset from the reference center frequency, directly indicating the start and end points of the supported frequency bandwidth, or by using the center frequency and bandwidth (1f-40).

[0223] The partial bandwidths are configured by an RRC connection setup RRCSetup message, an RRCResume message (1f-25), or an RRCReconfiguration message (1f-45, 1f-70). The RRC message includes configuration information related to a PCell, a Pscell, or multiple cells, and multiple partial bandwidths are configured for each cell (PCell, Pscell, or Scell). When multiple partial bandwidths are configured for each cell, multiple partial bandwidths are configured to be used in the downlink of each cell, and in the case of an FDD system, multiple partial bandwidths are configured to be used in the uplink of each cell, separate from the downlink partial bandwidth. In the case of a TDD system, multiple partial bandwidths are configured to be used commonly in the downlink and uplink of each cell.

[0224] The cell configuration information of each cell (PCell, Pscell, or Scell) or the information for partial bandwidth configuration includes some of the following information.

[0225] -Cell identifier (SCell index)

[0226] -Cell setting information

[0227] --First channel measurement setting information by cell or by partial bandwidth

[0228] --Second channel measurement setting information by cell or by partial bandwidth

[0229] - Cell downlink partial bandwidth configuration information

[0230] --Initial downlink BWP setting information

[0231] --Multiple partial bandwidth setting information and partial bandwidth identifier (BWPID) corresponding to each partial bandwidth

[0232] --Cell or downlink partial bandwidth initial state setting information (e.g., active state, dormant state, or inactive state)

[0233] --A partial bandwidth identifier indicating the first active downlink BWP

[0234] --Bandwidth fragment identifier indicating the basic bandwidth fragment (default BWP)

[0235] Configuration information for PDCCH monitoring related to each partial bandwidth, such as CORESET information, search space resource information, or PDCCH transmission resource, period, and subframe number information.

[0236] --A partial bandwidth identifier indicating a dormant partial bandwidth

[0237] --A partial bandwidth identifier that indicates the first partial bandwidth to be activated from sleep

[0238] --Partial bandwidth inactivity timer setting and its timer value

[0239] --First channel measurement setting information by cell or by partial bandwidth

[0240] --Second channel measurement setting information by cell or by partial bandwidth

[0241] - Cell uplink partial bandwidth setting information

[0242] --Initial uplink BWP setting information

[0243] --Multiple partial bandwidth setting information and partial bandwidth identifier (BWP ID) corresponding to each partial bandwidth

[0244] --Cell or downlink partial bandwidth initial state setting information (e.g., active state, dormant state, or inactive state)

[0245] --A partial bandwidth identifier indicating the first active uplink partial bandwidth (first active uplink BWP)

[0246] Configuration information related to transmission resources for performing channel measurement in a dormant partial bandwidth or a partial bandwidth other than the dormant partial bandwidth and reporting the measurement results (e.g., PUCCH transmission resource information of a PCell, PUCCH SCell, or PSCell)

[0247] According to one embodiment, the first channel measurement configuration information includes a configuration information of a cell (e.g., PCell, PSCell, or SCell) of the cell group that includes frequent channel measurement signals (e.g., radio resources, or temporary reference signals (TRS), SSBs, channel state information reference signals (CSI-RS), or reference signals (RS)) so that the base station can temporarily transmit more or better measurement signals in order to quickly activate the cell group (or cell) or allow the terminal to perform channel measurement in the cell. The first channel measurement configuration information includes configuration information such as a period related to the frequent channel measurement signal, information on the transmission resource to be transmitted (frequency or time transmission resource on which the frequent channel measurement signal is transmitted), its interval or number of times (number of times the frequent channel measurement signal is transmitted), a timer value (time on which the frequent channel measurement signal is transmitted), or a time interval (interval on which the frequent channel measurement signal is transmitted (e.g., offset of a time unit (slot, subframe, or symbol, etc.))). In addition, the first channel measurement configuration information includes configuration information such as a transmission resource on which the UE must report the measurement result, its period, its interval, timing, or offset.

[0248] The first channel measurement configuration information shortens the reporting period (or transmission resource) for the terminal to report channel measurement results, or configures transmission resources for channel measurement so that the base station can transmit many channel measurement signals (or transmission resources (e.g., radio resources or temporary reference signals (TRS)) frequently) in order to support the terminal in performing fast channel measurements or measuring many signals. The first channel measurement configuration information includes configuration information related to channel measurement signals for a specific terminal (or terminals) in a cell or partial bandwidth. For example, the first channel measurement configuration information includes the period of the channel measurement signals, the number of signals to be transmitted, the period in which the signals are transmitted, an offset related to the time in which the signals are transmitted, or the time length between transmitted signals. Alternatively, the first channel measurement configuration information includes a list of multiple channel measurement signals to be transmitted, time transmission resources (or frequency transmission resources) indicating the positions of the transmitted signals, transmission resources (time transmission resources or frequency transmission resources) for reporting measurement results, or a period for reporting measurement results.

[0249] According to one embodiment, the first channel measurement configuration information is configured differently for each cell or partial bandwidth for multiple cells or partial bandwidths configured by the RRC message, and is configured together with beam-related configuration information (TCI (transmission configuration indication) state or QCL (quasi co-location)) such as beam direction, beam number, or beam position to help the terminal easily measure transmission resources for measuring channels.

[0250] According to one embodiment, the first channel measurement configuration information configures a timing advance (TA) value (or offset value) for synchronizing a downlink signal or an uplink signal of the base station, a time alignment timer (TAT) for indicating the validity of the TA value, or a timer value (TAT value), thereby enabling the terminal to correctly perform channel measurement or channel measurement reporting. Furthermore, the first channel measurement configuration information configured by the RRC message includes a plurality of pieces of channel measurement signal information. By indicating one piece of channel measurement signal information or beam configuration information among the plurality of pieces of channel measurement signal information configured by the RRC message, MAC CE, or DCI, the terminal applies or uses the indicated channel measurement signal information or beam configuration information to perform channel measurement or channel measurement reporting. The indication method defines a mapping between a bitmap, an index, an identifier, and each piece of configured channel measurement signal information, and performs indication based on the mapping.

[0251] According to another embodiment, the channel measurement signal information is configured or indicated by an RRC message or a MAC CE, so that the terminal applies or utilizes the configured (or indicated) channel measurement signal information to perform channel measurement or to make a channel measurement report.

[0252] According to an embodiment of the present disclosure, the first channel measurement configuration information is initially deactivated when configured by an RRC message or after handover, and is subsequently activated by MAC control information, DCI information of a PDCCH, or an RRC message proposed in the present disclosure. When configured by an RRC message, the initial state is deactivated so that the base station can easily manage the cell state or channel measurement procedure of the terminal and accurately perform timing related to when and how the terminal performs channel measurement without the problem of RRC message processing delay.

[0253] The RRC message (RRCReconfiguration or RRCResume) also includes or configures secondary channel measurement configuration information, which includes general channel measurement configuration information such as the transmission resource, period, time interval, or number of times of a channel measurement signal, or the transmission resource, period, or time interval for a channel measurement report.

[0254] The configured initial BWP, default BWP, or first active BWP is used for the following purposes and operates as follows to suit those purposes:

[0255] The initial partial bandwidth (initial BWP) is a cell-specific partial bandwidth defined for each cell. It is used when a terminal connecting to a cell for the first time establishes a connection to the cell through a random access procedure, or when a terminal that has established a connection can synchronize. The base station configures an initial downlink partial bandwidth (initial downlink BWP) to be used in the downlink and an initial uplink partial bandwidth (initial uplink BWP) to be used in the uplink, respectively, for each cell. Configuration information related to the initial partial bandwidth is broadcast in the first system information (SIB1) indicated by CORESET, and the base station further configures the initial partial bandwidth to terminals that have established a connection via an RRC message. The initial partial bandwidth is designated as partial bandwidth identifier 0 in the uplink and downlink, respectively. That is, all terminals connected to the same cell use the same initial partial bandwidth designated as partial bandwidth identifier 0. This is because when performing a random access procedure, the base station transmits a random access response (RAR) message in an initial partial bandwidth that can be read by all terminals, which has the advantage of facilitating a contention-based random access procedure.

[0256] The first active BWP is configured differently for each UE (UE specific) and is designated as a partial bandwidth identifier in multiple partial bandwidths. The first active BWP is configured for each downlink and uplink and is configured as a partial bandwidth identifier in the first active downlink BWP and the first active uplink BWP. The first active BWP is used to indicate which partial bandwidth is to be activated and used first when multiple partial bandwidths are configured in one cell. For example, when a Pcell or a Pscell and multiple Scells are configured in a UE and multiple partial bandwidths are configured in each Pcell, Pscell, or Scell, if the Pcell, Pscell, or Scell ​​is activated, the UE activates and uses the first active BWP in the multiple partial bandwidths configured in the Pcell, Pscell, or Scell. That is, for the downlink, the first active downlink BWP is activated and used, and for the uplink, the first active uplink BWP is activated and used.

[0257] The operation of the terminal for a cell to switch the current or activated downlink link partial bandwidth and activate the first activated downlink link partial bandwidth (or the partial bandwidth set or indicated by an RRC message), or to switch the current or activated uplink link partial bandwidth and activate the first activated uplink link partial bandwidth (or the partial bandwidth set or indicated by an RRC message) is performed when the terminal receives an instruction to activate a cell or an activated cell whose partial bandwidth is in an inactive or dormant state, or receives an instruction to switch from an inactive or dormant partial bandwidth to a general partial bandwidth or to activate it via an RRC message, MAC control information, or DCI of the PDCCH. In addition, when the terminal receives an instruction to transition an activated cell or partial bandwidth to a dormant state, or an instruction to switch to or activate a dormant partial bandwidth, via an RRC message, MAC control information, or DCI of the PDCCH, the terminal switches the partial bandwidth to a dormant partial bandwidth, activates it, or puts the partial bandwidth to dormant.

[0258] In this disclosure, dormancy or switching to a dormant partial bandwidth, or activation of a dormant partial bandwidth means performing the operation proposed in the dormant state. That is, the UE performs an operation of measuring the channel for the downlink partial bandwidth (or the dormant partial bandwidth) and reporting it to the base station without monitoring the PDCCH. Alternatively, when activating or switching an activated cell or partial bandwidth to a general partial bandwidth, the dormant partial bandwidth is set to the initial activated downlink, uplink partial bandwidth, or basic partial bandwidth in order to switch the downlink partial bandwidth, activate the initial activated downlink partial bandwidth, switch the uplink partial bandwidth, and activate the initial activated uplink partial bandwidth. The basic partial bandwidth (default BWP) is set differently for each UE (UE specific) and is indicated by specifying a partial bandwidth identifier in multiple partial bandwidths. The basic partial bandwidth is set only for the downlink. The basic partial bandwidth is used as a partial bandwidth to which the activated partial bandwidth among the plurality of downlink partial bandwidths falls back after a certain period of time.

[0259] For example, a partial bandwidth inactivity timer (BWP inactivity timer) is set per cell or per partial bandwidth using an RRC message. The timer is started or restarted when data transmission / reception occurs in an activated partial bandwidth other than the basic partial bandwidth, or when an activated partial bandwidth is switched to another partial bandwidth. If the timer expires, the UE falls back or switches the activated downlink partial bandwidth in the cell to the basic bandwidth. Switching refers to a procedure of deactivating the currently activated partial bandwidth and activating the partial bandwidth for which switching is indicated. Switching is triggered by an RRC message, MAC control element, or downlink control information (DCI) of L1 signaling (PDCCH). Switching is triggered by indicating the partial bandwidth to be switched to or activated, and the partial bandwidth is indicated by a partial bandwidth identifier (e.g., 0, 1, 2, 3, or 4).

[0260] The reason why the basic partial bandwidth is applied and used only for the downlink is that the base station can easily perform base station scheduling by having the terminal fall back to the basic partial bandwidth after a certain period of time for each cell and receiving an instruction from the base station (e.g., DCI of the PDCCH). For example, if the base station sets the basic partial bandwidth of a terminal connected to a cell as the initial partial bandwidth, the base station continues to issue scheduling instructions only using the initial partial bandwidth after a certain period of time. If the basic partial bandwidth is not set by an RRC message, the initial partial bandwidth is considered to be the basic partial bandwidth, and the base station falls back to the initial partial bandwidth when the partial bandwidth deactivation timer expires.

[0261] Alternatively, in order to increase the flexibility of the base station implementation, a basic partial bandwidth is defined and set for the uplink as well, and is used in the same manner as the basic partial bandwidth for the downlink.

[0262] A dormant partial bandwidth (dormant BWP) refers to a partial bandwidth that is a dormant mode of an activated cell or a dormant partial bandwidth (dormant BWP inactivated SCell). Alternatively, when a dormant partial bandwidth is activated, the terminal cannot exchange data with the base station, does not monitor the PDCCH to confirm the base station's instructions, or does not transmit a pilot signal, but performs channel measurement and reports the measurement results related to the measured frequency / cell / channel periodically or when an event occurs according to the base station settings. Therefore, since the terminal does not monitor the PDCCH or transmit a pilot signal in the dormant partial bandwidth (dormant BWP) of an activated cell, it can save battery power compared to the general partial bandwidth (or a partial bandwidth that is not the dormant partial bandwidth) of an activated cell, or compared to when the general partial bandwidth (or a partial bandwidth that is not the dormant partial bandwidth) of an activated cell is activated, and unlike when the cell is deactivated, the base station can activate the general partial bandwidth of the activated cell earlier based on the measurement report or the measurement report of the dormant partial bandwidth of the activated cell, allowing the base station to use carrier aggregation technology earlier and reduce transmission delay.

[0263] The first activated partial bandwidth (or the first activated non-dormant partial bandwidth) to be activated from dormancy is the partial bandwidth of one activated cell of the terminal when the terminal is operating the partial bandwidth of that cell as a dormant partial bandwidth, when the activated partial bandwidth of the activated cell is a dormant partial bandwidth, or when the terminal switches to a dormant partial bandwidth in a cell, and when the terminal receives a PDCCH DCI, MAC CE, or RRC message from the base station to switch the partial bandwidth of the activated cell from the dormant partial bandwidth to a general partial bandwidth (or a partial bandwidth that is not a dormant partial bandwidth), or when the terminal receives a PDCCH DCI, MAC CE, or RRC message to switch or convert the activated partial bandwidth in the dormant partial bandwidth to a general partial bandwidth, or when the terminal receives a command to switch or convert or activate the activated partial bandwidth in the dormant partial bandwidth to a general partial bandwidth (e.g., the first activated partial bandwidth to be activated from dormancy), the partial bandwidth to which the terminal must switch or activate the partial bandwidth of the activated cell according to the above command is the first activated partial bandwidth to be activated from dormancy set by the RRC message.

[0264] In the present disclosure, the meaning of switching a first partial bandwidth to a second partial bandwidth is interpreted as meaning activating the second partial bandwidth, or as meaning deactivating an activated first partial bandwidth and activating the first partial bandwidth.

[0265] In addition, in the RRC connection setup RRCSetup message or RRCResume message (1f-25), or the RRCReconfiguration message (1f-45), a state transition timer is configured so that the terminal performs state transition by itself without receiving an instruction from the base station by an RRC message, MAC control information, or DCI of the PDCCH. For example, the terminal configures a cell deactivation timer (ScellDeactivationTimer) for each cell, and transitions the cell to a deactivated state when the cell deactivation timer expires.

[0266] In addition, the RRC connection setup RRCSetup message, RRCResume message (1f-25), or RRCReconfiguration message (1f-45) includes frequency measurement configuration information, frequency measurement gap configuration information, etc., and includes frequency measurement object information. In addition, the RRC connection setup RRCSetup message, RRCResume message (1f-25), or RRCReconfiguration message (1f-45) sets a function for reducing power consumption of the UE (power saving mode), and includes a function for reducing power consumption, as well as configuration information such as a DRX (discontinuous reception) cycle, offset, on-duration period (a period in which the UE must monitor the PDCCH), or time information, time information or short time period information regarding when the UE must monitor or detect the PDCCH from the base station before the on-duration period in the DRX cycle. If a function for reducing power consumption of the terminal is configured, the terminal configures a DRX cycle and detects a wake-up (WUS) signal in a period set to monitor the base station's PDCCH before the on-duration period, and the base station instructs the terminal to skip (or not perform) or perform PDCCH monitoring in the immediately following on-duration period using the PDCCH DCI of the WUS signal. Compared to the terminal having to constantly monitor the PDCCH in the on-duration period, the base station uses the WUS signal to instruct the terminal not to monitor the PDCCH in the on-duration period, thereby reducing battery consumption of the terminal.

[0267] Once the RRC connection setup is complete, the UE configures multiple partial bandwidths according to the instruction set by the RRC message. To save battery power, the UE activates one or a few of the configured partial bandwidths. For example, one partial bandwidth to be activated is indicated. The base station then instructs activation of the partial bandwidth and switches from the initial connection partial bandwidth to the new partial bandwidth using an RRC message, MAC control information (MAC CE), or L1 signaling (a PHY layer control signal such as a DCI on the PDCCH). Alternatively, the base station defines new bitmap information using the DCI on the PDCCH to indicate whether to activate a general partial bandwidth (or a partial bandwidth other than a dormant partial bandwidth), activate a dormant partial bandwidth, or deactivate a partial bandwidth. Alternatively, the base station uses the bitmap to indicate whether to activate a general partial bandwidth (e.g., the first activated partial bandwidth activated from dormancy), activate a dormant partial bandwidth, switch to a dormant partial bandwidth, or perform partial bandwidth switching. Because there are many other newly connected users in the initial connection partial bandwidth, it is still advantageous to allocate new partial bandwidths and manage connected users separately in terms of scheduling. This is because the initial connection partial bandwidth is not set for each terminal but is shared and used by all terminals. In addition, to reduce signaling overhead, the default partial bandwidth is dynamically indicated by MAC control information, L1 signaling, or system information.

[0268] An RRC message (RRC Setup message or RRC Resume message (1f-25), or RRC Reconfiguration message (1f-70)) includes configuration information for a cell group. The configuration information for a cell group includes some or more of the following information, or indicates the status or procedure related to each cell group, or the application or release of configuration information.

[0269] -Cell group identifier indicating a cell group (e.g., cell group identifier or its index)

[0270] - indicator of the state of the cell group (e.g., active, suspended, or inactive)

[0271] -Indicators that indicate the state of a cell group (e.g., an indicator to suspend (or deactivate) a cell group (e.g., a Cellgroup (SCG) suspension indicator) or an indicator to resume (or activate) a cell group (e.g., a Cellgroup (SCG) resumption indicator))

[0272] - An indicator that triggers a procedure of the corresponding protocol layer (e.g., SDAP layer, PDCP layer, RLC layer, or MAC layer) according to an indicator indicating the state of the cell group (e.g., a PDCP re-establishment indicator, a PDCP data recovery indicator, an indicator that triggers a new procedure, an RLC re-establishment indicator, a MAC layer initialization indicator, or a MAC layer partial initialization indicator).

[0273] If an indicator to suspend (or deactivate) the state of the cell group is included, the terminal configures second DRX configuration information (e.g., the length, period, or offset of the monitoring duration or activation duration) to perform PDCCH monitoring at a very long period in the PSCell of the cell group. For example, when the terminal receives an indicator to suspend the cell group, the terminal applies the second DRX configuration information and performs PDCCH monitoring at a very long period to save terminal power. Alternatively, when the terminal receives an indicator to suspend the cell group, the terminal applies partial bandwidth configuration information related to the PSCell of the cell group and activates or switches the dormant partial bandwidth for the downlink partial bandwidth of the PSCell of the cell group, thereby performing the terminal operation in a cell in which the dormant partial bandwidth is activated as proposed in the present disclosure. Also, when the terminal receives an indicator to suspend the cell group, the terminal deactivates all SCells configured in the cell group. Alternatively, if the UE receives an indicator to discontinue a cell group, for SCells configured in the cell group and for which a dormant partial bandwidth is configured, the UE activates or switches the dormant partial bandwidth for the downlink partial bandwidth, and performs the UE operation in the cell in which the dormant partial bandwidth is activated as proposed in the present disclosure, or deactivates SCells for which a dormant partial bandwidth is not configured. Alternatively, if the UE receives an indicator to discontinue a cell group using an RRC message, the UE activates / deactivates or puts each SCell into dormancy, or activates the dormant partial bandwidth, according to configuration information or an indicator related to each SCell in the cell group included in the RRC message, or before or after receiving the indicator to discontinue a cell group, the UE activates / deactivates or puts each SCell into dormancy, or activates the dormant partial bandwidth, according to a PDCCH indicator (e.g., bitmap), MAC control information, or RRC message.

[0274] Configuration information related to transmission resources for performing channel measurement in a dormant partial bandwidth or a partial bandwidth other than the dormant partial bandwidth and reporting the measurement results (e.g., PUCCH transmission resource information of a PCell, PUCCH SCell, or PSCell)

[0275] If an indicator to resume (or activate) the state of the cell group is included, the terminal configures first DRX configuration information (e.g., the length, period, or offset of the monitoring duration or activation duration) to further perform PDCCH monitoring in the PSCell of the cell group. Alternatively, the terminal restores and applies the first DRX configuration information stored for the cell group. For example, when the terminal receives an indicator to resume the cell group, the terminal applies the first DRX configuration information stored or received from an RRC message, performs PDCCH monitoring, and resumes data transmission or data reception. Alternatively, when the terminal receives an indicator to resume the cell group, the terminal applies partial bandwidth configuration information for the PSCell of the cell group, activates or switches the downlink partial bandwidth of the PSCell of the cell group to a partial bandwidth other than the dormant partial bandwidth (e.g., the partial bandwidth configured by the RRC message), and performs the terminal operation in a cell in which a general partial bandwidth (a partial bandwidth other than the dormant partial bandwidth) is activated as proposed in the present disclosure. Alternatively, if the terminal receives an indicator to resume the cell group, it applies the random access configuration information (such as random access transmission resource information (time transmission resource or frequency transmission resource) for transmitting a preamble, or specified preamble information) stored or received from the RRC message, and triggers a random access procedure in the PSCell of the cell group.Alternatively, when the UE receives an indication to resume a cell group, if the RRC message includes random access configuration information (random access transmission resource information (time transmission resource or frequency transmission resource) for transmitting a preamble, or specified preamble information, etc.), the UE applies the random access configuration information and triggers a random access procedure (e.g., contention-free random access) in the PSCell of the cell group; if the RRC message indicating the resumption or activation of the cell group does not include random access configuration information (random access transmission resource information (time transmission resource or frequency transmission resource) for transmitting a preamble, or specified preamble information, etc.), the UE triggers a random access procedure (e.g., contention-based random access) in the PSCell of the cell group, or triggers a random access procedure (e.g., contention-based random access) or 2-step random access based on system information. If there is random access configuration information (random access transmission resource information (time transmission resource or frequency transmission resource) for transmitting a preamble, or designated preamble information, etc.) stored in the terminal before receiving the indication to resume the cell group, the information is released or discarded. Alternatively, the terminal performs PDCCH monitoring in the indicated or configured cell group or cell, and triggers and performs a random access procedure as instructed by the PDCCH.

[0276] If an indicator to resume (or activate) the state of the cell group is included, or if the UE receives an indicator to resume the cell group, it activates all SCells configured in the cell group. Alternatively, if the UE receives an indicator to resume the cell group, it activates or switches the downlink partial bandwidth of an SCell configured in the cell group for which a dormant partial bandwidth is configured to a partial bandwidth other than the dormant partial bandwidth (e.g., a partial bandwidth configured by an RRC message or an initial activated partial bandwidth), and performs the UE operation in the cell in which a partial bandwidth other than the dormant partial bandwidth is activated as proposed in the present disclosure, or activates an SCell for which a dormant partial bandwidth is not configured. Alternatively, if the terminal receives an indicator to resume a cell group via an RRC message, it activates, deactivates, or puts each SCell into sleep mode, or performs sleep partial bandwidth activation on each SCell in the cell group according to the configuration information or indicator related to each SCell in the cell group included in the RRC message, or it activates, deactivates, or puts each SCell into sleep mode, or performs sleep partial bandwidth activation on each SCell in the cell group according to a PDCCH indicator (e.g., bitmap), MAC control information, or RRC message before or after receiving the indicator to resume a cell group.

[0277] -Directive to add cell group settings

[0278] -Indicator to cancel cell group setting

[0279] -Security setting information (security key information, security key information for cell group, or additional information (e.g., sk-counter)

[0280] -Indicator for instructing handover, cell group addition, or cell group change (e.g., ReconfigurationWithSync indicator or mobilitycontrolInfo indicator)

[0281] - First channel measurement setting information by cell or by partial bandwidth

[0282] - Second channel measurement setting information by cell or by partial bandwidth

[0283] -An indicator for adding a cell group setting, an indicator for instructing a cell group change (ReconfigurationWithSync), or an indicator for instructing a random access procedure (ReconfigurationWithSync or a newly defined indicator)

[0284] -An indicator (ReconfigurationWithSync or a newly defined indicator) that indicates whether to perform a random access procedure when activating a cell group and activate the cell group, or to activate the cell group without a random access procedure

[0285] RRM (radio resource management) setting information, frequency measurement setting information, separate RRM (radio resource management) setting information that must be applied or performed when deactivating a cell group, or frequency measurement setting information (e.g., simplified frequency measurement setting information for battery saving (reduced or relaxed RRM setting information)

[0286] Configuration information for radio link monitoring (RLM) or configuration information for RLM that must be applied or performed when a cell group is deactivated. For example, configuration information for RLM or configuration information for RLM that must be applied or performed when a cell group is deactivated may be configuration information for cell-based beams that a terminal must measure when a cell group is deactivated, or configuration information for beams per partial bandwidth, and may include beam-related configuration information (transmission configuration indication (TCI) state or quasi co-location (QCL)). Alternatively, configuration information for RLM or configuration information for RLM that must be applied or performed when a cell group is deactivated may include a timing advance (TA) value (or offset value) for synchronizing a base station downlink signal or a base station uplink signal, a timer (TAT: time alignment timer) indicating the validity of the TA value, or a timer value (TAT value). Alternatively, the configuration information for RLM, or the configuration information for RLM that must be applied or performed when a cell group is deactivated, includes synchronization signal block (SSB) configuration information that must be measured, channel state information reference signal (CSI-RS) configuration information, reference signal (RS) configuration information, and transmission resource information for reporting the result when a beam failure occurs (e.g., PUCCH configuration information (e.g., scheduling request (SR) information or specific transmission resource), frequency transmission resource, or time transmission resource). The configuration information also includes partial bandwidth configuration information (e.g., which may be indicated by a partial bandwidth identifier) ​​that indicates in which partial bandwidth the RLM procedure is to be performed.Alternatively, when the cell group state is in the deactivated state, the UE performs the RLM procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) configured by the RRC message, and when activating the cell group, the UE quickly monitors the first activated partial bandwidth to be activated, thereby minimizing cell group activation delay. Alternatively, when the cell group state is set to the deactivated state (or the activated state), the UE may perform the RLM procedure in the partial bandwidth that was last (or previously) activated before the cell group state was deactivated, and continue to maintain the connection state with the cell group (e.g., when partial bandwidth configuration information indicating which partial bandwidth the RLM procedure is to be performed in is not configured), or when activating the cell group, the UE may perform the activation procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) configured by the RRC message. If partial bandwidth-related configuration information indicating which partial bandwidth to perform the RLM procedure on when activating a cell group is not configured, the UE performs the RLM procedure on the partial bandwidth that was activated last (or previously). The configuration information also includes beam-related configuration information (e.g., a partial bandwidth identifier, or TCI state or QCL configuration information) indicating which beam to perform the RLM procedure on. Alternatively, when the cell group state is in a deactivated state, the UE performs the RLM procedure on the beam configured by the RRC message (e.g., TCI state or QCL configuration information), or activates a beam and performs the RLM procedure. This minimizes cell group activation delay by quickly monitoring the beam to be activated when activating a cell group.Alternatively, if the cell group state is set to a deactivated state (or an activated state), the UE may perform the RLM procedure in the beam that was last (or previously) activated before the cell group state was deactivated and continue to maintain a connection state with the cell group (e.g., if beam-related configuration information indicating which beam the RLM procedure is to be performed in is not configured), or when activating a cell group, the activation procedure is performed in the beam configured by the RRC message. If beam-related configuration information indicating which beam the RLM procedure is to be performed in is not configured when activating a cell group, the UE performs the RLM procedure in the beam that was last (or previously) activated.

[0287] Configuration information for beam failure detection procedures, BFD (beam failure detection), or BFD that must be applied or performed when a cell group is deactivated. For example, configuration information for beam failure detection procedures, BFD, or BFD that must be applied or performed when a cell group is deactivated. When a cell group is deactivated, the UE must measure cell-based beam configuration information or partial bandwidth-based beam configuration information, and includes beam-related configuration information (transmission configuration indication (TCI) state or quasi co-location (QCL)). Alternatively, configuration information for beam failure detection procedures, BFD, or BFD that must be applied or performed when a cell group is deactivated. The configuration information includes a timing advance (TA) value (or offset value) for synchronizing the downlink signal of the base station or the uplink signal of the base station, and a timer (TAT: time alignment timer) or timer value (TAT value) that indicates the validity of the TA value. Alternatively, the beam failure detection procedure, configuration information for BFD, or configuration information for BFD that must be applied or performed when a cell group is deactivated, includes synchronization signal block (SSB) configuration information that must be measured, channel state information reference signal (CSI-RS) configuration information, reference signal (RS) configuration information, and transmission resource information (e.g., PUCCH configuration information (e.g., scheduling request (SR) information or specific transmission resource), or frequency transmission resource or time transmission resource) for reporting the result when a beam failure occurs. The configuration information also includes partial bandwidth configuration information (e.g., which may be indicated by a partial bandwidth identifier) ​​that indicates which partial bandwidth the beam failure detection procedure will be performed on.Alternatively, when the cell group state is in the deactivated state, the UE performs the beam failure detection procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) set by the RRC message, and when activating the cell group, the UE quickly monitors the first activated partial bandwidth that must be activated, thereby minimizing the cell group activation delay. Alternatively, when the cell group state is set to the deactivated state (or the activated state), the UE may perform the beam failure detection procedure in the partial bandwidth that was last (or previously) activated before the cell group state was deactivated, and continue to maintain the connection state with the cell group (e.g., when partial bandwidth configuration information indicating which partial bandwidth the beam failure detection procedure is to be performed in is not set), or when activating the cell group, the UE may perform the activation procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) set by the RRC message. If partial bandwidth-related configuration information indicating which partial bandwidth to perform the beam failure detection procedure in is not configured when activating a cell group, the UE performs the beam failure detection procedure in the partial bandwidth that was activated last (or previously). The configuration information also includes beam-related configuration information (e.g., a partial bandwidth identifier, a TCI state, or QCL configuration information) indicating which beam to perform the beam failure detection procedure in. Alternatively, when the cell group state is in an inactive state, the UE performs the beam failure detection procedure in the beam (e.g., TCI state or QCL configuration information) configured by the RRC message. By quickly monitoring the beams that need to be activated when activating a cell group, the UE minimizes cell group activation delay.Alternatively, when the cell group state is set to a deactivated state (or an activated state), the UE may perform a beam failure detection procedure in the beam that was last (or previously) activated before the cell group state was deactivated, and continue to maintain a connection state with the cell group (e.g., when beam-related configuration information indicating in which beam the beam failure detection procedure is to be performed is not configured), or when the cell group is activated, the activation procedure is performed in the beam configured by the RRC message. If beam-related configuration information indicating in which beam the beam failure detection procedure is to be performed is not configured when the cell group is activated, the UE performs a beam failure detection procedure in the beam that was last (or previously) activated.

[0288] In order to efficiently perform the dual connectivity technology configuration procedure (or SCG configuration procedure) or handover procedure, the message introduces a first timer (e.g., T304), a second timer (e.g., T310), a third timer (e.g., T312), or a fourth timer (e.g., a fallback timer), which are set by the message. The timers are proposed to be driven and applied in the dual connectivity technology configuration procedure or handover procedure. The first timer (e.g., T304) is a timer for determining whether the dual connectivity technology configuration procedure or handover procedure has been successfully performed, the second timer (e.g., T310) is a timer for determining whether the radio connection is active, and the third timer (e.g., T312) is an auxiliary timer for determining whether the radio connection is active, and is a timer for triggering a frequency measurement procedure and reporting the frequency measurement result. The fourth timer (e.g., a timer for fallback) is a timer introduced to perform a fallback procedure and attempt cell group activation in a random access procedure (general random access procedure (four-phase random access procedure or two-phase random access procedure) when activation of a cell group (or an SCG or a PSCell) fails (i.e., when the timer expires) without the random access procedure proposed in the present disclosure. The fourth timer is also the first timer, and the first timer is used as the timer for fallback.

[0289] If an RRC message (e.g., an RRCReconfiguration message) includes an indicator for suspending (or deactivating) a cell group, it is proposed not to include an indicator for instructing handover, cell group addition, or cell group change (e.g., a ReconfigurationWithSync indicator or a mobilitycontrolInfo indicator), and if it includes an indicator for resuming a cell group or configuration information for configuring a cell group, it is proposed to include an indicator for instructing handover, cell group addition, or cell group change (e.g., a ReconfigurationWithSync indicator or a mobilitycontrolInfo indicator). This is because, when a cell group is resumed, connection with the cell group must be further established, and therefore synchronization must be achieved, system information must be received, or, if necessary, a random access procedure must be performed. For example, when the base station sets the cell group of the terminal to a deactivated state using an RRC message, it restricts the setting of a cell group addition indicator or a cell group change indicator, an indicator indicating a random access procedure, or a ReconfigurationWithSync indicator, so that the terminal does not perform unnecessary synchronization procedures, connection procedures, or random access procedures.

[0290] In the following, in this disclosure, a dormant partial bandwidth is newly proposed for the next generation mobile communication system, and specific terminal operations in each partial bandwidth when transitioning or switching between the partial bandwidths are proposed.

[0291] FIG. 1G illustrates a state transition by fractional bandwidth, or fractional bandwidth switching procedure, according to one embodiment of the present disclosure.

[0292] 1G, according to one embodiment, the bandwidth portion (BWP) of each cell (e.g., SCell or PSCell) of each cell group of a terminal is activated as a general bandwidth portion (1g-01), activated as a dormant bandwidth portion (1g-02), or deactivated as a dormant bandwidth portion (1g-03). Note that the general bandwidth portion or the dormant bandwidth portion of each cell group of a terminal is activated or deactivated according to an instruction by configuration information of an RRC message, MAC control information, or DCI of a PDCCH.

[0293] The state transition operations (activation, deactivation, or dormancy) for each partial bandwidth of a cell proposed in this disclosure, or the operation of activating a general partial bandwidth, activating a dormant partial bandwidth, activating the first activated partial bandwidth activated from dormancy, or deactivating a general partial bandwidth or dormant partial bandwidth, are performed by instruction or setting in one of the following cases:

[0294] -If the cell's partial bandwidth state is set by an RRC message, or if the partial bandwidth of each cell is set by an RRC message, and a dormant partial bandwidth is set in the cell, or if the initial activation partial bandwidth is set to the dormant partial bandwidth, switch to or activate the dormant partial bandwidth, start the cell, and perform operation in the dormant partial bandwidth.

[0295] - When a MAC CE for cell activation, deactivation or dormancy is received

[0296] When a MAC CE is received to activate or deactivate a general partial bandwidth, the first activated partial bandwidth from sleep, or a sleep partial bandwidth

[0297] When receiving a PDCCH DCI to activate, deactivate, or switch a general partial bandwidth, the first activated partial bandwidth from sleep, or a sleep partial bandwidth

[0298] - If a cell dormancy timer is not set for an active cell and the set cell inactivity timer expires

[0299] - If the partial bandwidth dormancy timer is not set for the active state partial bandwidth and the set partial bandwidth state inactivity timer (e.g., bwpInactivityTimer) expires

[0300] Furthermore, the state transition operation or dormant partial bandwidth operation method proposed in this disclosure has the following features.

[0301] -The Spcell (Pcell or Pscell, or the cell's downlink partial bandwidth or uplink partial bandwidth) does not have a dormant partial bandwidth configured, and only the general partial bandwidth is configured and constantly activated. The Spcell synchronizes and transmits / receives primary control signals. If the Spcell's partial bandwidth is made dormant or inactivated, or if it is operated in the dormant partial bandwidth, it is disconnected from the base station. Therefore, it must be constantly maintained in an activated state.

[0302] -If the PUCCH is configured for a partial bandwidth of an Scell ​​or SCell, the dormant state or dormant partial bandwidth is not configured. Because there are other cells that must send feedback such as HARQ ACK / NACK via the PUCCH, the active state or general partial bandwidth must be activated and used.

[0303] -Due to the above characteristics, the cell deactivation timer (ScellDeactivationTimer) or partial bandwidth dormancy timer is not applied to the Spcell or partial bandwidth of the Spcell and the partial bandwidth of the Scell ​​or SCell for which PUCCH is configured, but is only operated for other Scells.

[0304] The cell or partial bandwidth dormancy timer (ScellHibernationTimer) takes precedence over the cell or partial bandwidth state deactivation timer (ScellDeactivationTimer). If a timer value is set by an RRC message, the same value is applied to all cells. Alternatively, the base station can apply different timer values ​​to each Scell ​​or BWP, taking into account the characteristics of each Scell ​​or BWP.

[0305] Unless a cell or partial bandwidth is instructed to be activated or dormant by an RRC message, it basically initially operates in a deactivated state.

[0306] In the present disclosure, the uplink refers to the uplink partial bandwidth, and the downlink refers to the downlink partial bandwidth, because only one activated or dormant partial bandwidth can be operated for each uplink or downlink.

[0307] In the present disclosure, an active state, a deactivated state, or a dormant state is operated, and when a cell or a partial bandwidth undergoes transition or switching, it is performed in units of partial bandwidths, and when a state transition or switching occurs in units of partial bandwidths, the partial bandwidth (downlink partial bandwidth or uplink partial bandwidth) for which a state transition or switching is instructed undergoes state transition or switching in accordance with the state transition or switching instruction. For example, when a partial bandwidth (downlink or uplink partial bandwidth) is to transition from an active state to a dormant state or to be switched (or activated) to a dormant partial bandwidth, the partial bandwidth is transitioned to the dormant state or switched (or activated) to the dormant partial bandwidth.

[0308] In the present disclosure, partial bandwidth switching (BWP switching) means that when partial bandwidth switching is indicated by the DCI of the PDCCH and a downlink assignment is assigned and switching is indicated by a partial bandwidth identifier, the downlink partial bandwidth is switched to the partial bandwidth indicated by the partial bandwidth identifier; and when partial bandwidth switching is indicated by the DCI of the PDCCH and a UL grant is assigned and switching is indicated by a partial bandwidth identifier, the uplink partial bandwidth is switched to the partial bandwidth indicated by the partial bandwidth identifier. Furthermore, since the PDCCH DCI format itself is different, with a format for downlink assignment (format 1) and a format for UL grant (format 0), the uplink and downlink need not be described separately, and the terminal operation may be performed according to the DCI format.

[0309] The method of managing state transitions at a bandwidth part level proposed in the present disclosure and the operation of the bandwidth part according to each state are extended and applied to various embodiments. In the following of the present disclosure, specific embodiments in which the contents proposed in the present disclosure are extended and applied will be described.

[0310] FIG. 1H is a diagram illustrating a DRX configuration or DRX operation method that can conserve the battery of a terminal according to one embodiment of the present disclosure.

[0311] In Fig. 1H, the base station configures DRX capabilities, such as a DRX cycle, its start point, its offset, or its on-duration (active time), in the PCell, SCell, or PSCell by an RRC message to the terminal, as in Fig. 1F. In the present disclosure, configuring the DRX capabilities in the PCell, SpCell, or PSCell is considered.

[0312] If the DRX function is configured in the PCell (or SpCell or PSCell), the UE applies the DRX function taking into account the DRX cycle (1h-03) and the DRX start time or its offset. When the DRX function is applied, the UE monitors the PDCCH or PDCCH DCI received from the base station on the PCell only during the DRX activation time period (on-duration or active time (1h-01)). In addition, outside the DRX function activation time period (outside active time (1h-02)), the UE does not monitor the PDCCH or PDCCH DCI, which can reduce battery consumption of the UE.

[0313] In FIG. 1H, the base station configures a power saving mode in the terminal via an RRC message to further reduce battery consumption in the terminal. If the power saving mode is configured together with the DRX mode, the terminal monitors the PDCCH outside the active time interval (1h-04) configured by the RRC before the active time (1h-01) in which the terminal must monitor the PDCCH in the DRX mode, and monitors and receives a wake-up signal (WUS) outside the active time interval. In the PDCCH DCI bit of the WUS signal, the base station indicates whether the terminal must monitor the PDCCH in the next active time (1h-05, 1h-07) or does not need to monitor the PDCCH.

[0314] That is, a terminal configured with a power saving function or DRX function monitors the WUS signal for a short time period (1h-04) set by an RRC message before each activation time (1h-05), and if the value of the DCI bit of the PDCCH related to the next activation time (1h-05, 1h-07) in the received WUS signal is 0 (or 1), the terminal is instructed not to monitor the PDCCH for the next activation time (1h-07), or the timer corresponding to the next activation time is not driven in the MAC layer so that the terminal does not monitor the PDCCH. If the value of the DCI bit of the PDCCH related to the next activation time (1h-05, 1h-07) in the received WUS signal is 1 (or 0), the terminal is instructed to monitor the PDCCH during the next activation time (1h-05), or the timer corresponding to the next activation time is driven in the MAC layer and the terminal is instructed to monitor the PDCCH.

[0315] Furthermore, the terminal does not monitor the WUS signal or the PDCCH for detecting the WUS signal during the activation time interval.

[0316] In addition, when a terminal configured with the power saving function or DRX function monitors a WUS signal for a short time period (1h-04) configured by an RRC message before each activation time (1h-05), it checks the PDCCH using a first RNTI identifier (e.g., PS-RNTI) to detect the signal. The first RNTI identifier (e.g., PS-RNTI) is configured for multiple terminals, and the base station uses the first RNTI identifier (e.g., PS-RNTI) to instruct multiple terminals whether to monitor or not monitor the PDCCH in the next activation time period.

[0317] In addition, when a terminal configured with the power saving function or DRX function monitors and detects the PDCCH during the activation time (1h-05), it detects signals based on the second RNTI (e.g., C-RNTI), third RNTI (e.g., MCS-C-RNTI), or fourth RNTI (SPS-C-RNTI or CS-RNTI) configured to be specific to the terminal in the RRC message. The second RNTI (e.g., C-RNTI) is used to indicate general terminal scheduling, the third RNTI (e.g., MCS-C-RNTI) is used to indicate the terminal's modulation and coding scheme, and the fourth RNTI (SPS-C-RNTI or CS-RNTI) is used to indicate the terminal's periodic transmission resource.

[0318] Based on the method proposed in Figure 1H, the base station uses the DCI of the PDCCH to instruct the UE to activate, deactivate, or put into sleep the state of the cell or cell group of the UE during the activation time (1h-05) or short time interval (1h-04) set by the RRC message. Also, the UE performs a PDCCH monitoring procedure to receive an instruction regarding the state of the cell or cell group during the activation time (1h-05) or short time interval (1h-04) set by the RRC message. If dual connectivity technology is configured for the UE, the UE monitors the PDCCH in the PCell of the MCG during the activation time (1h-05) or short time interval (1h-04) configured by the RRC message, receives an indication from the DCI of the PDCCH regarding the activation state, deactivation state, or dormancy state of the cell (SCell) of the MCG or the PSCell (or SCell) of the SCG, and the UE performs a cell (or partial bandwidth) activation procedure, deactivation procedure, dormancy procedure, or partial bandwidth switching procedure accordingly. That is, the base station instructs the UE to activate, deactivate, or dormant state of the cell (SCell) of the MCG or the PSCell (or SCell) of the SCG using the DCI of the PDCCH during the activation time (1h-05) or short time interval (1h-04) configured by the RRC message in the PCell of the MCG.

[0319] FIG. 1I is a diagram illustrating the concept of a method for operating a dormant fractional bandwidth in an activated SCell or PSCell according to one embodiment of the present disclosure.

[0320] As shown in FIG. 1I, the base station configures a plurality of SCells for the UE using an RRC message, assigns each SCell identifier, and configures a dormant partial bandwidth for each SCell for carrier aggregation technology, or configures a plurality of cell groups for the UE and assigns a cell group identifier for dual connectivity technology. The base station also configures or instructs the UE to configure a cell group abort indicator for each cell group or a PSCell of each cell group, and configures a dormant bandwidth. The base station configures a plurality of SCells for the UE, each SCell group including a plurality of SCells.

[0321] According to one embodiment, a SCell group identifier is assigned to each SCell group, and multiple SCell identifiers are configured to be included in or mapped to each SCell group identifier. The SCell identifier value or SCell group identifier value is assigned with a predetermined bit value and has an integer value (or a natural number value). Alternatively, the PSCells of each cell group are indicated by the cell group identifier.

[0322] 1I, according to one embodiment, the base station defines a new bitmap for the DCI of the PDCCH transmitted on the PCell, and maps each bit value of the bitmap to indicate a SCell identifier value, a SCell group identifier value, a cell group (or secondary cell group) identifier, or a PSCell (or SCell) of the cell group (or secondary cell group). In addition, the base station defines a value for each bit and indicates whether to switch to a dormant partial bandwidth, activate a dormant partial bandwidth, or suspend or resume a cell group for the SCell, SCell belonging to the SCell group, cell group (or secondary cell group), or PSCell (or SCell) of the cell group (or secondary cell group) corresponding to the bit. The base station also instructs whether to switch from a dormant partial bandwidth to a general partial bandwidth (e.g., the first activated partial bandwidth when activated from dormancy) or activate the general partial bandwidth (e.g., the first activated partial bandwidth when activated from dormancy) for the SCell corresponding to the bit, the SCell belonging to the SCell group, the cell group (or secondary cell group) identifier, or the PSCell (or SCell) of the cell group (or secondary cell group).

[0323] In FIG. 1I, after receiving DCI of the PDCCH in the PCell (1i-01), the terminal reads the DCI and checks whether there is a bitmap including an instruction related to the partial bandwidth of an SCell or SCell group (e.g., switching to or activating a dormant partial bandwidth, or switching to or activating a general partial bandwidth), or an instruction to suspend or resume a cell group (or a secondary cell group), or a PSCell (or SCell) of the cell group (or the secondary cell group). If there is a bitmap, the terminal switches or activates the partial bandwidth, or suspends or resumes the cell group, according to the bit value, for the SCell or SCell (1i-02, 1i-03) belonging to the SCell group, the cell group (or the secondary cell group), or the PSCell (or SCell) of the cell group (or the secondary cell group) indicated by each bit of the bitmap.

[0324] For example, if a bit in the bitmap indicates the first SCell (or the first SCell identifier (1i-02)), the cell group (or the secondary cell group), or the PSCell (or the SCell) of the cell group (or the secondary cell group), or indicates the group of SCells (or the group identifier of the SCells) in which the first SCell is included, and the bit value is 0 (or 1), the UE may For a PSCell (or SCell) of the cell group (or secondary cell group), the partial bandwidth (1i-21) is activated to the dormant partial bandwidth (1i-22), or the current partial bandwidth is switched to the dormant partial bandwidth (1i-22), or if the current partial bandwidth is not the dormant partial bandwidth, the currently activated partial bandwidth (1i-21) is switched to the dormant partial bandwidth (1i-22) or activated (1i-25), or the cell group is stopped or deactivated. Alternatively, the partial bandwidth of the cell group (or secondary cell group) or the PSCell (or SCell) of the cell group (or secondary cell group) is maintained as is, and the second DRX configuration information or the second SRS configuration information proposed in the present disclosure is applied to perform PDCCH monitoring at a long period or to transmit SRS at a long period, thereby reducing the power consumption of the UE.

[0325] In FIG. 1I, after receiving DCI of the PDCCH in the PCell (1i-01), the terminal reads the DCI and checks whether there is a bitmap including an instruction related to a partial bandwidth of an SCell or SCell group (e.g., switching to or activating a dormant partial bandwidth, or switching to or activating a general partial bandwidth), or an instruction related to a cell group (or a secondary cell group), a partial bandwidth of a PSCell (or SCell) in the cell group (or secondary cell group), or an instruction to suspend or resume the cell group. If there is a bitmap, the terminal switches or activates the partial bandwidth, or suspends or resumes the cell group according to the bit value for the SCell, SCell (1i-02, 1i-03) belonging to the SCell group, cell group (or secondary cell group), or PSCell (or SCell) in the cell group (or secondary cell group) indicated by each bit in the bitmap.

[0326] For example, if a bit in the bitmap indicates a second SCell (or a second SCell identifier (1i-03)), or indicates a group of SCells (or a group identifier of SCells) in which the second SCell is included, a cell group (or a secondary cell group), or a PSCell (or an SCell) of a cell group (or a secondary cell group), and the bit value is 1 (or 0), the terminal determines, for the second SCell (1i-03), whether the currently activated partial bandwidth is a dormant partial bandwidth (1i-32). ), if the currently activated partial bandwidth is not the general partial bandwidth, or if the current partial bandwidth (or cell) is activated and the current partial bandwidth is activated at the dormant partial bandwidth (1i-32) (or if a partial bandwidth that is not the general partial bandwidth is activated), the partial bandwidth of the second SCell (1i-03) is switched or activated to the partial bandwidth set by the RRC message (e.g., the first activated partial bandwidth activated from dormancy, 1i-33) (1i-35), or the cell group is resumed or activated.

[0327] According to one embodiment, when the bit value is 1 (or 0), if the SCell, the SCell belonging to the SCell group, the cell group (or secondary cell group), or the PSCell (or SCell) of the cell group (or secondary cell group) indicated by the bit must be switched or activated to a partial bandwidth that is not a dormant partial bandwidth, or if the cell group must be resumed, the SCell or each SCell belonging to the SCell group does not apply, ignore, or read the bit value if the SCell state is a deactivated state, or if the SCell state is an activated state and the activated partial bandwidth is not a dormant partial bandwidth (or a general partial bandwidth), or if the cell group (or secondary cell group) or the PSCell (or SCell) of the cell group (or secondary cell group) is already in an activated state or resumed state. Also, since the bit value is 0 (or 1), if the SCell or SCell belonging to the SCell group indicated by the bit, the cell group (or secondary cell group), or the PSCell (or SCell) of the cell group (or secondary cell group) must be switched to or activated in the dormant partial bandwidth, or if the cell group must be discontinued, each SCell belonging to the SCell or SCell group does not apply, ignore, or read the bit value if the SCell state is an activated state and the activated partial bandwidth is the dormant partial bandwidth. Or, if the cell group (or secondary cell group) or the PSCell (or SCell) of the cell group (or secondary cell group) is already in a discontinued or deactivated state, does not apply, ignore, or read the bit value.

[0328] In the present disclosure, a method for quickly activating a cell (SCell, PSCell, or SCell) is proposed below.

[0329] Specifically, the base station configures, by an RRC message (RRCReconfiguration or RRCResume), first channel measurement configuration information for quickly measuring and reporting channels when the terminal activates a cell. In order to quickly activate a cell group (or a cell) or to enable the terminal to quickly perform channel measurement in a cell, the base station temporarily transmits more or better channel measurement signals. The first channel measurement configuration information is used to configure the configuration information of a cell (e.g., PCell, PSCell, or SCell) of the cell group to include frequent channel measurement signals (e.g., radio resource, temporary reference signal (TRS), synchronization signal block (SSB), channel state information reference signal (CSI-RS), or reference signal (RS)). The first channel measurement configuration information includes configuration information such as a period related to the frequent channel measurement signal, information on the transmission resource to be transmitted (frequency or time transmission resource on which the frequent channel measurement signal is transmitted), its period, its number of times (number of times the frequent channel measurement signal is transmitted), its timer value (time on which the frequent channel measurement signal is transmitted), or time period (period on which the frequent channel measurement signal is transmitted (e.g., offset of a time unit (slot, subframe, or symbol, etc.))). In addition, the first channel measurement configuration information includes configuration information such as a transmission resource on which the UE must report the measurement result, its period, its period, its timing, or its offset.

[0330] The first channel measurement configuration information shortens the reporting period (or transmission resource) for the terminal to report channel measurement results, or configures transmission resources for channel measurement so that the base station can transmit many channel measurement signals (or transmission resources (e.g., radio resources or temporary reference signals (TRS))) frequently) in order to support the terminal's fast channel measurement or multiple signal measurements. The first channel measurement configuration information includes configuration information related to channel measurement signals for a specific terminal (or terminals) in a cell or partial bandwidth.

[0331] According to one embodiment, the first channel measurement configuration information is configured differently for each cell or each partial bandwidth for multiple cells or partial bandwidths configured by the RRC message, and is configured together with beam-related configuration information (TCI (transmission configuration indication) state or QCL (quasi co-location)) such as a beam direction, beam number, or beam position to help the terminal easily measure the transmission resources for measuring the channel.

[0332] According to an embodiment, the first channel measurement configuration information configures a timing advance (TA) value (or offset value) for synchronizing a downlink signal or an uplink signal of a base station, a time alignment timer (TAT) indicating the validity of the TA value, or a timer value (TAT value), thereby enabling a terminal to correctly perform channel measurement or channel measurement reporting. For example, the first channel measurement configuration information may include a period of a channel measurement signal, or the number of signals to be transmitted, a period for transmitting the signal, an offset related to the time at which the signal is transmitted, or a time length between transmitted signals. Alternatively, the first channel measurement configuration information may include a list of a plurality of channel measurement signals to be transmitted, time transmission resources (or frequency transmission resources) indicating the positions of the transmitted signals, transmission resources (time transmission resources or frequency transmission resources) for reporting measurement results, a period for reporting the measurement results, or beam-related configuration information (transmission configuration indication (TCI) state or quasi co-location (QCL)) for measuring the channel measurement signals, etc.

[0333] Furthermore, the first channel measurement configuration information configured by the RRC message includes multiple pieces of channel measurement signal information, and by indicating one piece of channel measurement signal information or beam configuration information from the multiple pieces of channel measurement signal information configured by the RRC message, MAC CE, or DCI, the UE applies or uses the indicated channel measurement signal information or beam configuration information to perform channel measurement or to generate a channel measurement report. The indication method defines a mapping between a bitmap, index, and identifier and each piece of configured channel measurement signal information, and indicates the information based on the mapping. Alternatively, the channel measurement signal information is configured or indicated by the RRC message or MAC CE. The UE applies or uses the configured (or indicated) channel measurement signal information to perform channel measurement or to generate a channel measurement report.

[0334] Alternatively, when the first channel measurement configuration information is included in an RRC message and configured in a terminal, if the cell state is set to an active state using the RRC message and an instruction to activate the cell is issued using the RRC message, the first channel measurement configuration information is applied or used to measure or report channels quickly, thereby activating the cell quickly. For example, the first channel measurement configuration information, channel measurement signal information, or beam-related configuration information to be applied when the cell state is set to an active state using the RRC message and an instruction to activate the cell using the RRC message is configured as separate configuration information (default configuration) using the RRC message, or if channel measurement signal information (or beam-related configuration information) corresponding to identifier 0 or only one channel measurement signal information (or beam-related configuration information) is configured, that channel measurement signal information (or beam-related configuration information) is applied.

[0335] According to an embodiment of the present disclosure, the first channel measurement configuration information can be configured only for the downlink partial bandwidth configuration information of each cell. That is, according to an embodiment of the present disclosure, the first channel measurement configuration information is not configured for the uplink partial bandwidth configuration information of each cell. This is because the UE must first measure a downlink channel and then report the measurement result for that channel or cell, and then correctly receive the PDCCH and follow instructions from the base station.

[0336] The first channel measurement configuration information proposed in the present disclosure is initially deactivated when configured by an RRC message or after handover, and is subsequently activated by MAC control information, DCI information of PDCCH, or an RRC message proposed in the present disclosure. When configured by an RRC message, the initial state must be deactivated so that the base station can easily manage the cell state or channel measurement procedure of the terminal, and the timing related to when and how the terminal performs channel measurement can be accurately performed without the problem of RRC message processing delay.

[0337] The RRC message (RRCReconfiguration or RRCResume) also includes or configures secondary channel measurement configuration information, which includes general channel measurement configuration information such as the transmission resource, period, time interval or number of times of a channel measurement signal, or the transmission resource, period, or time interval for a channel measurement report.

[0338] Hereinafter, in this disclosure, as proposed, when first channel measurement setting information or second channel measurement information is configured in a terminal by an RRC message, a structure or indication method of MAC control information (MAC control element) is proposed, which, while activating a cell, measures a channel quickly based on the first channel measurement setting information or reports the measurement result, thereby activating the cell quickly. For example, the MAC control information (or RRC message) proposed in the present disclosure instructs which cell among multiple cells (SCells) configured in RRC to activate or deactivate, or if it instructs which cell to activate, the MAC control information (or RRC message) instructs which measurement signal information among the first channel measurement configuration information configured by the RRC message to apply, how to measure the signal (e.g., instructing which signal transmission resource to measure, how many signals to transmit, in which time interval to measure, based on which offset to determine the measurement time interval, at which period to measure the signal, or in which transmission resource to measure the signal), or how to report it (e.g., instructing which measurement result to report, in which time interval to report the measurement result, based on which offset to determine the measurement result report transmission resource, at which period to report the measurement result, or in which transmission resource to report the measurement result), so that the cell is activated early based on the first channel measurement configuration information configured by the RRC message.

[0339] FIG. 1J is a diagram illustrating a method in which an RRC inactive mode terminal operates, according to one embodiment of the present disclosure.

[0340] In the present disclosure, a cell group or a cell refers to a PCell of a master cell group (MCG), or an SCell of an MCG, a PSCell of a secondary cell group (SCG), or an SCell of an SCG.

[0341] In one embodiment, it is proposed that in the RRC connected mode, the SCell configuration information (e.g., the configuration information described or proposed in FIG. 1F) configured or stored for the proposed embodiment as shown in FIG. 1F, or the PSCell (or SCell) configuration information of a cell group (e.g., a secondary cell group), is not released or discarded but continues to be stored even when the UE transitions to the RRC inactive mode. It is also proposed that when performing an RRC connection resumption procedure, the UE in the RRC inactive mode determines whether to discard or release, maintain and apply, or reconfigure the stored SCell configuration information (e.g., the configuration information described or proposed in FIG. 1F) or the PSCell (or SCell) configuration information of a cell group (e.g., a secondary cell group) via an indicator in an RRCResume message or an RRCReconfiguration message transmitted by the base station or via a reconfiguration procedure. In addition, when the base station transmits an RRCRelease message including a configuration or indicator for transitioning the UE to the RRC inactive mode to the UE, the base station transmits to the UE an indicator or configuration information instructing whether to discard, release, maintain and apply, or reconfigure the SCell configuration information (e.g., the configuration information described in FIG. 1F or the proposed configuration information) or the PSCell (or SCell) configuration information of a cell group (e.g., a secondary cell group) stored in the RRCRelease message. In addition, when the UE performs mobility in the RRC inactive mode and performs a RAN notification area update, the base station receives and applies an indicator or configuration information instructing whether to discard, release, maintain and apply, or reconfigure the SCell configuration information (e.g., the configuration information described in FIG. 1F or the proposed configuration information) or the PSCell (or SCell) configuration information of a cell group (e.g., a secondary cell group) stored in the RRCRelease message transmitted by the base station to the UE.

[0342] In an embodiment proposed in the present disclosure, the base station allows the initial activation partial bandwidth of the downlink or uplink partial bandwidth configuration information of each cell to be set to the dormant partial bandwidth in the SCell configuration information of an RRC message (e.g., the configuration information described or proposed in FIG. 1F) or the PSCell (or SCell) configuration information of a cell group (e.g., a secondary cell group), so that when the terminal activates each SCell, each cell group, or a PSCell of each cell group, the downlink partial bandwidth or uplink partial bandwidth of each SCell, each cell group, or a PSCell of each cell group is immediately operated as the dormant partial bandwidth, or the cell group is suspended or resumed, thereby reducing battery consumption of the terminal.

[0343] Alternatively, in an embodiment proposed in the present disclosure, the base station does not set the initial activation partial bandwidth of the downlink or uplink partial bandwidth configuration information of each cell to the dormant partial bandwidth in the SCell configuration information of the RRC message (e.g., the configuration information described or proposed in FIG. 1F) or the PSCell (or SCell) configuration information of the cell group (e.g., the secondary cell group), and when the terminal activates or resumes each SCell, each cell group, or the PSCell of each cell group, the downlink link partial bandwidth or uplink partial bandwidth of each SCell, each cell group, or the PSCell of each cell group is always activated to the initial activation partial bandwidth, and is switched or activated to the dormant partial bandwidth in the embodiment proposed in the present disclosure, or the cell group is discontinued or resumed, thereby reducing battery consumption of the terminal.

[0344] In addition, in the proposed embodiment, the present invention is extended to and applied to each SCell configuration information or PSCell configuration information of a master cell group (MCG) or a secondary cell group (SCG) of a UE configured with dual connectivity. That is, the SCell configuration information or PSCell configuration information of the SCG is also stored when the UE transitions to an RRC inactive mode, and when an RRC connection resumption procedure is performed or the UE transitions to an RRC inactive mode, an RRC message (e.g., RRCResume, RRCReconfiguration, or RRCRelease) is transmitted to the UE, including an indicator or configuration information instructing whether to discard, release, maintain and apply, or reconfigure the stored SCell configuration information of the MCG or SCG (e.g., configuration information described or proposed in FIG. 1F) or PSCell configuration information.

[0345] In Figure 1J, a terminal 1j-01 establishes a network connection with a base station 1j-02 and transmits and receives data 1j-05. If the base station needs to transition the terminal to an RRC inactive mode for a certain reason, the base station transmits an RRCRelease message 1j-20 to transition the terminal to an RRC inactive mode. The RRC message (e.g., RRCRelease) includes an indicator or configuration information instructing the terminal to discard, release, maintain and apply, or reconfigure the stored SCell configuration information of the MCG or SCG (e.g., the configuration information described or proposed in Figure 1F) or the PSCell (or SCell) configuration information of the cell group (e.g., a secondary cell group). In the case of a terminal that applies dual connectivity technology, the base station determines whether to suspend or resume the master cell group bearer setup, RRC configuration information, MCG, or SCell configuration information of the SCG, and determines whether to suspend or resume the secondary cell group bearer setup and RRC configuration information by inquiring of the secondary cell base station whether to suspend or resume and receiving the response (1j-15). In addition, using the RRCRelease message, the base station configures a frequency list, frequency measurement configuration information, or frequency measurement period for the terminal to measure in the RRC idle mode or RRC inactive mode.

[0346] When an RRC inactive mode terminal is moving and receives a paging message (1j-25), or when there is a need to transmit uplink data, or when there is a need to update the RAN indication field, it performs the RRC connection resumption procedure.

[0347] When the terminal needs to establish a connection, it performs a random access procedure and transmits an RRCResumeRequest message to the base station. The proposed terminal operation related to the transmission of the message is as follows (1j-30).

[0348] 1. The UE checks the system information, and if the system information indicates that a full terminal connection resume identifier (I-RNTI or Full resume ID) is to be transmitted, the UE prepares to include the stored full terminal connection resume identifier (I-RNTI) in a message and transmit it. If the system information indicates that a divided terminal connection resume identifier (truncated I-RNTI or truncated resume ID) is to be transmitted, the UE constructs the stored full terminal connection resume identifier (I-RNTI) with a terminal connection resume identifier (truncated resume ID) divided in a predetermined manner and prepares to include the divided I-RNTI in a message and transmit it.

[0349] 2. The terminal restores RRC connection establishment information and security context information from the stored terminal context.

[0350] 3. The terminal then updates a new KgNB security key corresponding to the master cell group based on the current KgNB security key, the NH (Next Hop) value, and the NCC value received and stored in the RRCRelease message.

[0351] 4. If the terminal receives the SCG-counter value (or sk-counter) in the RRCRelease message, it updates the new SKgNB security key corresponding to the secondary cell group based on the KgNB security key and the SCG-counter value (or sk-counter) value.

[0352] 5. The terminal then uses the newly updated KgNB security keys to derive new security keys (K_RRCenc, K_RRC_int, K_UPint, K_UPenc) for use in integrity protection, verification procedures, and encryption and decryption procedures.

[0353] 6. If the terminal receives the SCG-counter value (or sk-counter) in the RRCRelease message, it uses the newly updated SKgNB security key corresponding to the secondary cell group to derive new security keys (SK_RRCenc, SK_RRC_int, SK_UPint, SK_UPenc) to be used in integrity protection, verification procedures, and encryption and decryption procedures.

[0354] 7. The terminal then calculates the MAC-I and prepares to include it in a message for transmission.

[0355] 8. The terminal then resumes SRB1 (which must have been resumed beforehand in order to receive an RRCResume message on SRB1 in response to the RRCResumeRequest message it is transmitting).

[0356] 9. Compose an RRCResumeRequest message and transmit it to the lower layer.

[0357] 10. Apply the updated security keys and previously configured algorithms to all bearers (MCG terminated RBs) except SRB0 corresponding to the master cell group, resume the integrity protection and verification procedure, and apply integrity verification and protection to data transmitted and received thereafter (to increase the reliability and security of data transmitted and received from SRB1 or DRB thereafter).

[0358] 11. Apply the updated security keys and previously configured algorithms to all bearers (MCG terminated RBs) except SRB0 corresponding to the master cell group, resume the encryption and decryption procedures, and apply encryption and decryption to data that will be sent and received from now on (to increase the reliability and security of data sent and received from SRB1 or DRB from now on).

[0359] 12. If the UE receives the SCG-counter value (or sk-counter) in the RRCRelease message, it applies the updated security keys and previously configured algorithms to all bearers (SCG terminated RBs) corresponding to the secondary cell group, resumes the integrity protection and verification procedure, and applies integrity verification and protection to data that will be transmitted and received thereafter (to increase the reliability and security of data transmitted and received from the DRB thereafter).

[0360] 13. If the UE receives the SCG-counter value (or sk-counter) in the RRCRelease message, it applies the updated security keys and previously configured algorithms to all bearers (SCG terminated RBs) corresponding to the secondary cell group, resumes the encryption and decryption procedure, and applies encryption and decryption to data that will be transmitted and received thereafter (to increase the reliability and security of data transmitted and received from the DRB).

[0361] When the UE needs to establish a connection, performs a random access procedure, transmits an RRCResumeRequest message to the base station, and then receives an RRCResume message in response thereto, the suggested UE behavior is as follows (1j-35): If the RRCResume message includes an indicator to report valid frequency measurement results measured in the RRC inactive mode, the UE reports the frequency measurement results in an RRCResumeComplete message. In addition, in an RRC message (e.g., RRCResume), the base station transmits to the UE an indicator or configuration information instructing the UE to discard, release, maintain and apply, or reconfigure the MCG or SCG SCell configuration information (e.g., the configuration information described in FIG. 1F or the proposed configuration information) stored in the UE.

[0362] 1. When the UE receives the message, it restores the PDCP state corresponding to the master cell group, resets the COUNT value, and re-establishes the PDCP hierarchy between the SRB2 corresponding to the master cell group and all DRBs (MCG terminated RBs).

[0363] 2. If the UE receives the SCG-counter value (or sk-counter) in the message, it updates a new SKgNB security key corresponding to the secondary cell group based on the KgNB security key and the SCG-counter (or sk-counter) value, and derives new security keys (SK_RRCenc, SK_RRC_int, SK_UPint, SK_UPenc) to be used in integrity protection, verification procedures, and encryption and decryption procedures using the newly updated SKgNB security key corresponding to the secondary cell group.

[0364] 3. If the message contains master cell group configuration information,

[0365] 3-1. Implement and apply the master cell group configuration information included in the message. The master cell group information includes configuration information related to the RLC layer belonging to the master cell group, logical channel identifiers, bearer identifiers, etc.

[0366] 4. If the message contains bearer configuration information (radioBearerConfig)

[0367] 4-1. Implement and apply the bearer configuration information (radioBearerConfig) included in the message. The bearer configuration information (radioBearerConfig) includes configuration information for the PDCP layer, configuration information for the SDAP layer, logical channel identifier, bearer identifier, etc. for each bearer.

[0368] 5. If the message contains secondary cell group (masterCellgroup) configuration information

[0369] 5-1. Implement and apply secondary cell group configuration information included in the message. The secondary cell group information includes configuration information related to the RLC layer belonging to the secondary cell group, a logical channel identifier, a bearer identifier, etc.

[0370] 6. If the message contains secondary bearer configuration information (radioBearerConfig)

[0371] 6-1. Implement and apply the secondary bearer configuration information (radioBearerConfig) included in the message. The secondary bearer configuration information (radioBearerConfig) includes configuration information for the PDCP layer, configuration information for the SDAP layer, logical channel identifier, bearer identifier, etc. for each secondary bearer.

[0372] 7. The terminal resumes SRB2 corresponding to the master cell group and all DRBs (MCG terminated RBs).

[0373] 8. If the message contains frequency measurement configuration information (measConfig)

[0374] 8-1. Implement and apply the frequency measurement setting information included in the message, i.e., perform frequency measurement according to the setting.

[0375] 9. The terminal transitions to the RRC connected mode.

[0376] 10. The terminal indicates to the upper layer that the suspended RRC connection has been resumed.

[0377] 11. Then, the RRCResumeComplete message is constructed and delivered to the lower layer for transmission (1j-40).

[0378] If the UE has bearer configuration information and UE context information related to the suspended secondary cell group, it performs frequency measurement based on system information or frequency configuration information set by the RRCRelease message or RRCResume message, and if a valid result is available, it transmits an indicator in the RRCResumeComplete message to indicate that the result is available. If the base station receives the indicator, it instructs the UE to report the frequency measurement result if it needs to resume carrier aggregation or dual connectivity (1j-45), and either reports the frequency measurement result or is reported the frequency measurement result in the RRCResumeComplete message (1j-50). If the base station receives the frequency measurement result, it asks the secondary cell base station whether to resume bearer information related to the suspended secondary cell group, makes a decision based on the response, and transmits an RRCReconfiguration message to the UE to instruct whether to resume or release the bearer related to the secondary cell group. In addition, the base station transmits an RRC message (e.g., RRCReconfiguration) to the terminal including an indicator or configuration information instructing the terminal to discard, release, maintain and apply, or reconfigure the MCG or SCG SCell configuration information (e.g., configuration information described or proposed in Figure 1F) stored in the terminal.

[0379] In an embodiment proposed in Figure 1J of the present disclosure, the base station allows the initial activation partial bandwidth of the downlink or uplink partial bandwidth configuration information of each cell to be set to the dormant partial bandwidth in the SCell configuration information (e.g., configuration information described or proposed in Figure 1F) of an RRC message (e.g., RRCRelease, RRCResume, or RRCReconfiguration) or the PSCell (or SCell) configuration information of a cell group (e.g., a secondary cell group), so that when a terminal activates a PSCell of each SCell or cell group (e.g., a secondary cell group), the base station immediately operates the downlink partial bandwidth or uplink partial bandwidth of each SCell or PSCell as the dormant partial bandwidth, or suspends or resumes the cell group, thereby reducing battery consumption of the terminal. For example, when the SCell state is set to an activated state or the cell group state is set to an activated state, suspended state, or deactivated state in the SCell configuration information or cell group configuration information of an RRC message (e.g., RRCRelease, RRCResume, or RRCReconfiguration), when an instruction to suspend or resume the cell group is set, or when an instruction to activate the SCell is received in the MAC control information proposed in this disclosure, each SCell or PSCell is activated, resumed, or suspended, and when the SCell or PSCell is activated, the downlink link partial bandwidth or uplink link partial bandwidth of the SCell or PSCell is immediately activated, thereby reducing battery consumption of the terminal.

[0380] As described above, when a UE in RRC inactive mode transitions to an RRC connected mode and restores, applies, or reconfigures the SCell configuration information or PSCell (or SCell) configuration information of a cell group (e.g., a secondary cell group) proposed in the present disclosure, switching between or activation of partial bandwidths, or activation or application of dormant partial bandwidths is performed for each activated SCell or PSCell (or SCell) of a cell group according to the embodiments proposed in the present disclosure. Also, the embodiments of the present disclosure are extended to be applied when performing handover.

[0381] According to the embodiments proposed in the present disclosure, if the terminal receives an indication of suspension or resumption, or activation or deactivation, for a cell, a cell group, or a PSCell of a cell group, the PHY layer or MAC layer that receives the indication passes the indication to a higher layer (e.g., the MAC layer, the RLC layer, the PDCP layer, or the RRC layer). If the higher layer receives an indication (e.g., suspension or resumption, or activation or deactivation, for a cell group) from a lower layer, it performs the corresponding protocol layer procedure for suspension or resumption, or activation or deactivation of the cell group. Alternatively, according to the embodiments of the present disclosure, if the terminal receives an indication of suspension or resumption, or activation or deactivation, for a cell group, or a PSCell of a cell group in an RRC message, the RRC layer that receives the indication passes the indication to a lower layer (e.g., the PHY layer, the MAC layer, the RLC layer, or the PDCP layer). When a lower layer receives an instruction (e.g., to stop or resume, or activate or deactivate, a cell group) from a higher layer (e.g., the RRC layer), it performs the protocol layer procedure for stopping or resuming, or activating or deactivating the corresponding cell group.

[0382] The embodiments proposed in this disclosure may be combined or expanded to form and operate various embodiments.

[0383] Figure 1K is a flowchart showing a signaling procedure for setting up or canceling dual connectivity technology, or activating or resuming, or suspending or deactivating a secondary cell group set up for dual connectivity technology, in the next-generation wireless communication system of the present disclosure.

[0384] In FIG. 1K, the first signaling procedure for setting up or releasing a dual connectivity technology, setting up or releasing a secondary cell group set up for dual connectivity technology, activating or resuming, or suspending or deactivating is as follows:

[0385] In FIG. 1K, the terminal establishes an RRC connection with a network or base station, as in FIG. 1F of the present disclosure, and transmits or receives data with the base station (e.g., a master cell group, a master node (MN), a master cell group (MCG), or a cell (PCell or SCell) of the master cell group).

[0386] The base station configures a dual connectivity technology for a terminal for a predetermined reason (e.g., when a high data transmission rate is required, or at the request of the terminal (1k-05), or when high QoS requirements must be met). For example, the terminal transmits a request to the base station to configure, release, activate, deactivate, resume, or discontinue a dual connectivity technology, cell group (e.g., secondary cell group), or cell, and the request message includes a frequency (or channel) measurement result report, cell group identifier, cell identifier, or measurement result (1k-05). Alternatively, the base station considers the amount of downlink (or uplink) data or buffer volume and determines whether to configure, release, add, deactivate or activate, resume, change, reconfigure, or discontinue a dual connectivity technology, cell group (e.g., secondary cell group), or cell.

[0387] A master base station (MN (master node) or MCG (master cell group)) receives a frequency or channel measurement report related to each frequency or channel received from a terminal and determines a secondary base station (SN (secondary node) or SCG (secondary cell group)) to set up a dual connectivity technology based on the measurement report. Alternatively, the master base station determines whether the base station should set up, release, add, deactivate or activate, resume, change, reconfigure, or cancel a dual connectivity technology, cell group (e.g., secondary cell group), or cell, taking into account the amount of downlink (or uplink) data or buffer volume. The master base station transmits a message to the determined secondary base station via the Xn interface (e.g., interface between base stations) or the Sn interface (interface between base stations and AMF or UMF, or interface between base stations) requesting whether the secondary base station can configure or add a dual connectivity technology, cell group (e.g., secondary cell group) or cell to the terminal in order to configure, release, add, deactivate, activate, resume, change, reconfigure, or cancel the secondary cell group (1k-10). In order for the secondary base station to configure, release, add, deactivate or activate, resume, modify, reconfigure or cancel a dual connectivity technology, cell group (e.g., secondary cell group), or cell, a new separate request message is defined and used, or a new indicator is defined in an existing message (e.g., SN addition request message, SN modification request message, or SN release request message) to instruct (or request) the secondary base station to configure, release, add, deactivate or activate, resume, modify, reconfigure, or cancel a cell group (e.g., secondary cell group) or cell.The request message includes information such as cell group configuration information (e.g., master cell group configuration information) currently set in the terminal, bearer configuration information, terminal capability information, or terminal frequency (or channel) measurement result information, so that the secondary base station refers to the information and configures the secondary cell group configuration information or bearer configuration information so that it matches the terminal capabilities, does not exceed the terminal capabilities, or matches the bearer configuration information of the master cell group.

[0388] If a secondary base station (SCG) that receives the request message (1k-10) rejects the request message, it constructs a rejection message and transmits the rejection message to the master base station via the Xn interface (e.g., the interface between base stations) or the Sn interface (the interface between a base station and an AMF or UMF, or the interface between base stations) (1k-15). If it accepts the request message, the secondary base station transmits a request acceptance message to the master base station via the Xn interface (e.g., the interface between base stations) or the Sn interface (the interface between a base station and an AMF or UMF, or the interface between base stations) (1k-15), which includes configuration information or indicators for configuring, releasing, adding, deactivating or activating, resuming, modifying, reconfiguring, or terminating a dual connectivity technology, cell group (e.g., a secondary cell group), or cell. The request acceptance message includes at least some of the following information:

[0389] - The same message identifier as that included in the request message, or an indicator that the request requested in the request message is accepted

[0390] Configuration information or indicators (e.g., configuration information or indicators for a master cell group) for configuring, deconfiguring, adding, deactivating, activating, restarting, modifying, reconfiguring, or canceling a dual connectivity technology, cell group (e.g., a secondary cell group), or cell.

[0391] A first RRC message (e.g., an RRCReconfiguration message) containing configuration information or indicators for configuring, deconfiguring, adding, deactivating, activating, resuming, modifying, reconfiguring, or canceling a dual connectivity technology, cell group (e.g., a secondary cell group), or cell.

[0392] The first RRC message includes at least some of the following information:

[0393] First RRC message identifier (e.g., rrc-transaction identifier) ​​for distinguishing a first RRC message. In order for a terminal and a base station (e.g., a secondary base station) to transmit or receive several RRC messages to each other, an identifier for distinguishing each RRC message is included in the RRC message. For example, the RRC message (e.g., RRCReconfiguration) transmitted by the transmitting end, the RRC message (e.g., RRCReconfigurationComplete) corresponding to the RRC message (e.g., RRCReconfiguration) transmitted by the receiving end, or the RRC message corresponding to the RRC message transmitted by the transmitting end includes the same first RRC message identifier.

[0394] --Configuration information or indicators (e.g., configuration information or indicators for a terminal) for configuring, deconfiguring, adding, deactivating, activating, resuming, modifying, reconfiguring, or canceling dual connectivity technologies, cell groups (e.g., secondary cell groups), or cells.

[0395] --Indicator indicating the state of the cell group (e.g., active, inactive, suspended, or resumed)

[0396] --Cell group identifier for distinguishing cell groups (the cell group identifier is assigned by the master base station or one of the already agreed identifiers is assigned by the secondary base station)

[0397] --Cell group setting information or cell setting information

[0398] Bearer configuration information, such as indicator information that instructs the operation of each bearer's protocol layer (e.g., SDAP layer, PDCP layer, RLC layer, or MAC layer) (e.g., PDCP abort indicator, PDCP re-establishment indicator, PDCP data recovery indicator, RLC re-establishment indicator, MAC partial initialization indicator, MAC initialization indicator, or indicator that triggers a new operation).

[0399] If the information includes configuration information or an indicator for setting up, adding, activating, resuming, changing, or reconfiguring a dual connectivity technology, a cell group (e.g., a secondary cell group), or a cell, the information also includes a first indicator (e.g., mobilityControlInfor or ReconfigurationWithSync). However, if the information includes configuration information or an indicator for releasing, deactivating, reconfiguring, or terminating a dual connectivity technology, a cell group (e.g., a secondary cell group), or a cell, the information does not include a first indicator (e.g., mobilityControlInfor or ReconfigurationWithSync). The first indicator may be an indicator for triggering a random access procedure in a cell group or cell, an indicator for achieving signal synchronization with a new cell, an indicator for instructing a terminal to move to a frequency, or an indicator for instructing a change of cell group (or cell).

[0400] --If the information includes configuration information or indicators for configuring, adding, activating, resuming, modifying, or reconfiguring a dual connectivity technology, a cell group (e.g., a secondary cell group), or a cell, random access configuration information is also included. However, if the information includes configuration information or indicators for releasing, deactivating, reconfiguring, or terminating a dual connectivity technology, a cell group (e.g., a secondary cell group), or a cell, random access configuration information is not included. The random access configuration information includes random access transmission resource information (time transmission resource or frequency transmission resource) for preamble transmission related to the cell group or cell, or designated preamble information.

[0401] --Time information indicating when to activate, resume, deactivate, or suspend a dual connectivity technology, cell group (e.g., secondary cell group) or cell (PSCell or SCGSCell) (e.g., timing information (e.g., X), time unit, subframe, time slot, or symbol unit), for example, if a message is received in the nth time unit, time information indicating whether to activate, resume, deactivate, or suspend a cell in the (n+X)th time unit)

[0402] --First channel measurement setting information by cell or by partial bandwidth

[0403] --Second channel measurement setting information by cell or by partial bandwidth

[0404] --An indicator to add a cell group setting, or an indicator to change a cell group (ReconfigurationWithSync), or an indicator to indicate a random access procedure (ReconfigurationWithSync or a newly defined indicator)

[0405] --An indicator (ReconfigurationWithSync or a newly defined indicator) that indicates whether to perform a random access procedure when activating a cell group and activate the cell group, or to activate the cell group without a random access procedure

[0406] -- RRM (radio resource management) setting information, frequency measurement setting information, separate RRM (radio resource management) setting information that must be applied or performed when a cell group is deactivated, or frequency measurement setting information (e.g., simplified frequency measurement setting information for battery saving (reduced or relaxed RRM setting information)

[0407] --Configuration information for RLM (radio link monitoring), or configuration information for RLM that must be applied or performed when a cell group is deactivated. For example, configuration information for RLM, or configuration information for RLM that must be applied or performed when a cell group is deactivated, is configuration information for cell-based beams that a terminal must measure when a cell group is deactivated, or configuration information for beams per partial bandwidth, and includes beam-related configuration information (transmission configuration indication (TCI) state or quasi co-location (QCL)). Alternatively, configuration information for RLM, or configuration information for RLM that must be applied or performed when a cell group is deactivated, includes a timing advance (TA) value (or offset value) for synchronizing the downlink signal of the base station or the uplink signal of the base station, a timer (TAT: time alignment timer) indicating the validity of the TA value, or a timer value (TAT value). Alternatively, the configuration information for RLM, or the configuration information for RLM that must be applied or performed when a cell group is deactivated, includes synchronization signal block (SSB) configuration information that must be measured, channel state information reference signal (CSI-RS) configuration information, reference signal (RS) configuration information, and transmission resource information for reporting the result when a beam failure occurs (e.g., PUCCH configuration information (e.g., scheduling request (SR) information or specific transmission resource), or frequency transmission resource or time transmission resource). The configuration information also includes partial bandwidth configuration information (e.g., indicated by a partial bandwidth identifier) ​​that indicates in which partial bandwidth the RLM procedure is to be performed.Alternatively, when the cell group state is in the deactivated state, the UE performs the RLM procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) configured by the RRC message, and when activating the cell group, the UE quickly monitors the first activated partial bandwidth to be activated, thereby minimizing cell group activation delay. Alternatively, when the cell group state is set to the deactivated state (or the activated state), the UE performs the RLM procedure in the partial bandwidth that was last (or previously) activated before the cell group state was deactivated, and continues to maintain the connection state with the cell group (e.g., when partial bandwidth configuration information indicating which partial bandwidth to perform the RLM procedure in is not configured), or when activating the cell group, the UE performs the activation procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) configured by the RRC message. If partial bandwidth-related configuration information indicating which partial bandwidth to perform the RLM procedure on when activating a cell group is not configured, the UE performs the RLM procedure on the partial bandwidth that was activated last (or previously). The configuration information also includes beam-related configuration information (e.g., a partial bandwidth identifier, TCI state, or QCL configuration information) indicating which beam to perform the RLM procedure on. Alternatively, when the cell group state is in a deactivated state, the UE performs the RLM procedure on the beam configured by the RRC message (e.g., TCI state or QCL configuration information), or activates a beam, performs the RLM procedure, and minimizes cell group activation delay by quickly monitoring the beam to be activated when activating a cell group.Alternatively, if the cell group state is set to a deactivated state (or an activated state), the UE performs the RLM procedure in the beam that was last (or previously) activated before the cell group state was deactivated and continues to maintain a connection state with the cell group (e.g., if beam-related configuration information indicating which beam the RLM procedure is to be performed in is not configured), or when activating the cell group, the UE performs the activation procedure in the beam configured by the RRC message. If beam-related configuration information indicating which beam the RLM procedure is to be performed in is not configured when activating the cell group, the UE performs the RLM procedure in the beam that was last (or previously) activated.

[0408] --Configuration information for beam failure detection procedures, BFD (beam failure detection), or BFD configuration information that must be applied or performed when a cell group is deactivated. For example, configuration information for beam failure detection procedures, BFD, or BFD configuration information that must be applied or performed when a cell group is deactivated is cell-based beam configuration information that a terminal must measure when a cell group is deactivated, or partial bandwidth-based beam configuration information, and includes beam-related configuration information (TCI (transmission configuration indication) state or QCL (quasi co-location)). Alternatively, configuration information for beam failure detection procedures, BFD, or BFD configuration information that must be applied or performed when a cell group is deactivated includes a timing advance (TA) value (or offset value) for synchronizing the downlink signal of a base station or the uplink signal of a base station, a timer (TAT: time alignment timer) indicating the validity of the TA value, or a timer value (TAT value). Alternatively, the beam failure detection procedure, configuration information for BFD, or configuration information for BFD that must be applied or performed when a cell group is deactivated, includes synchronization signal block (SSB) configuration information that must be measured, channel state information reference signal (CSI-RS) configuration information, reference signal (RS) configuration information, and transmission resource information that can report the results when a beam failure occurs (e.g., PUCCH configuration information (e.g., scheduling request (SR) information or specific transmission resource), or frequency transmission resource or time transmission resource). The configuration information also includes partial bandwidth configuration information (e.g., which can be indicated by a partial bandwidth identifier) ​​that indicates which partial bandwidth the beam failure detection procedure will be performed on.Alternatively, when the cell group state is in the deactivated state, the UE performs the beam failure detection procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) set by the RRC message, and when activating the cell group, the UE quickly monitors the first activated partial bandwidth that must be activated, thereby minimizing the cell group activation delay. Alternatively, when the cell group state is set to the deactivated state (or the activated state), the UE performs the beam failure detection procedure in the partial bandwidth that was last (or previously) activated before the cell group state was deactivated, and continues to maintain the connection state with the cell group (e.g., when partial bandwidth configuration information indicating which partial bandwidth the beam failure detection procedure is to be performed in is not set), or when activating the cell group, the UE performs the activation procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) set by the RRC message. If partial bandwidth-related configuration information indicating which partial bandwidth to perform the beam failure detection procedure on when activating a cell group is not configured, the UE performs the beam failure detection procedure on the partial bandwidth that was activated last (or previously). The configuration information also includes beam-related configuration information (e.g., a partial bandwidth identifier, TCI state, or QCL configuration information) indicating which beam to perform the beam failure detection procedure on. Alternatively, when the cell group state is in a deactivated state, the UE performs the beam failure detection procedure on the beam configured by the RRC message (e.g., TCI state or QCL configuration information), thereby minimizing cell group activation delay by quickly monitoring the beams that need to be activated when activating a cell group.Alternatively, if the cell group state is set to a deactivated state (or an activated state), the UE performs the beam failure detection procedure in the beam that was last (or previously) activated before the cell group state was deactivated, and continues to maintain a connection state with the cell group (e.g., if beam-related configuration information indicating which beam to perform the beam failure detection procedure in is not configured), or when activating the cell group, performs the activation procedure in the beam configured by the RRC message. If beam-related configuration information indicating which beam to perform the beam failure detection procedure in is not configured when activating the cell group, the UE performs the beam failure detection procedure in the beam that was last (or previously) activated.

[0409] --SDAP layer configuration information (sdap-config): SDAP layer configuration information is configured for each bearer and includes the following information: SDAP layer configuration information is configuration information that determines how to map QoS flow to a bearer (DRB) when an NR base station or E-UTRA base station is connected to 5GC (5G core), or whether or not an uplink (or downlink) SDAP header is present.

[0410] ---PDU session identifier (pdu-Session): The PDU session identifier indicates the PDU session of the QoS flow that is mapped to the bearer.

[0411] --- Downlink SDAP header presence indicator (sdap-HeaderDL): Indicates whether an SDAP header is present or not for the downlink data of the bearer. The downlink SDAP header presence indicator value is not changed after the bearer is established.

[0412] ---Indicator indicating whether an SDAP header is present or not for the uplink data of the bearer (sdap-HeaderUL): The indicator indicates whether an SDAP header is present or not for the uplink data of the bearer. If the bearer is set as the default bearer, the network sets the indicator indicating whether an SDAP header is present or not for the uplink data.

[0413] --- Default bearer indicator (default DRB): Indicates whether the configured bearer (or DRB) is the default bearer for the PDU session. The indicator value indicating the default bearer is set to TRUE for only one bearer (or instance) among bearers (or instances) belonging to the same PDU session (or having the same PDU session identifier value), and is set to FALSE for the remaining bearers. In other words, only one default bearer is configured for one PDU session.

[0414] ---Configuration information for adding QoS flow mapping information (mappedQoS-FlowsToAdd): Indicates a list of QFI identifiers (QFI: QoS flow identifier) ​​of uplink QoS flows of PDU sessions to be added and mapped to a bearer. One QFI identifier value is included and configured only once in the SDAP layer configuration information having the PDU session identifier value among all SDAP layer configuration information configured in the terminal. When configuring QoS flow remapping, the QFI identifier of the QoS flow to be remapped is included and configured only in the configuration information (mappedQoS-FlowsToAdd) that adds QoS flow mapping information of the SDAP layer configuration information corresponding to the new bearer (or the newly mapped bearer), and is not included in the configuration information (mappedQoS-FlowsToRelease) that releases QoS flow mapping information corresponding to the old bearer (or the previously mapped bearer).

[0415] ---Configuration information for releasing QoS flow mapping information (mappedQoS-FlowsToRelease): Indicates a list related to the QFI identifier (QFI: QoS flow identifier) ​​of the QoS flow of the PDU session to be released from the existing QoS flow bearer-mapped to the bearer.

[0416] When the master base station (MCG) receives the request acceptance message (1k-15), it checks the request acceptance message and transmits a second RRC message (e.g., RRCReconfiguration) including the information included in the request acceptance message (e.g., the first RRC message included in the request acceptance message (1k-15)) to the terminal (1k-20). The second RRC message includes at least some of the following information:

[0417] -Second RRC message identifier (e.g., rrc-transaction identifier) ​​for distinguishing the second RRC message. In order for a terminal and a base station (e.g., a master base station) to transmit or receive several RRC messages to each other, an identifier for distinguishing each RRC message is included in the RRC message. For example, an RRC message (e.g., RRCReconfiguration) transmitted by a transmitting end, or an RRC message (e.g., RRCReconfigurationComplete) corresponding to an RRC message (e.g., RRCReconfiguration) transmitted by a receiving end, or an RRC message corresponding to an RRC message transmitted by a transmitting end, includes the same second RRC message identifier.

[0418] - First RRC message included in the request acceptance message (1k-15)

[0419] Configuration information or indicators (e.g., configuration information or indicators for a terminal) for configuring, deconfiguring, adding, deactivating, activating, resuming, modifying, reconfiguring, or canceling a dual connectivity technology, cell group (e.g., a secondary cell group), or cell.

[0420] - indicators indicating the state of the cell group (e.g., activated, deactivated, suspended, or resumed)

[0421] -Cell group identifier for distinguishing cell groups. The cell group identifier is assigned by the master base station or one of the already agreed identifiers is assigned by the secondary base station.

[0422] -Cell group setting information or cell setting information

[0423] Bearer configuration information, such as indicator information instructing the operation of each bearer protocol layer (e.g., SDAP layer, PDCP layer, RLC layer, or MAC layer) (e.g., PDCP abort indicator, PDCP re-establishment indicator, PDCP data recovery indicator, RLC re-establishment indicator, MAC partial initialization indicator, MAC initialization indicator, or indicator triggering a new operation).

[0424] If configuration information or an indicator for configuring, adding, activating, resuming, modifying, or reconfiguring a dual connectivity technology, a cell group (e.g., a secondary cell group), or a cell is included, the first indicator (e.g., mobilityControlInfor or ReconfigurationWithSync) is also included. However, if configuration information or an indicator for releasing, deactivating, reconfiguring, or terminating a dual connectivity technology, a cell group (e.g., a secondary cell group), or a cell is included, the first indicator (e.g., mobilityControlInfor or ReconfigurationWithSync) is not included. The first indicator may be an indicator for triggering a random access procedure in a cell group or cell, an indicator for achieving signal synchronization with a new cell, an indicator for instructing a frequency move of the UE, or an indicator for instructing a change of cell group (or cell). Alternatively, the UE may monitor the PDCCH in the indicated or configured cell group or cell, and trigger and perform the random access procedure as instructed by the PDCCH. For example, a higher layer (e.g., RRC layer) transmits an indicator to a lower layer (e.g., MAC layer) to trigger a random access procedure.

[0425] -If the information includes configuration information or indicators for configuring, adding, activating, resuming, modifying, or reconfiguring a dual connectivity technology, a cell group (e.g., a secondary cell group), or a cell, random access configuration information is also included. However, if the information includes configuration information or indicators for releasing, deactivating, reconfiguring, or terminating a dual connectivity technology, a cell group (e.g., a secondary cell group), or a cell, random access configuration information is not included. The random access configuration information includes random access transmission resource information (time transmission resource or frequency transmission resource) for preamble transmission related to the cell group or cell, or designated preamble information.

[0426] -Time information indicating when to activate, resume, deactivate, or suspend a dual connectivity technology, cell group (e.g., secondary cell group), or cell (PSCell or SCGSCell) (e.g., timing information (e.g., X), time unit, subframe, time slot, or symbol unit), for example, if a message is received in the nth time unit, time information indicating whether to activate, resume, deactivate, or suspend a cell in the (n+X)th time unit)

[0427] - First channel measurement setting information by cell or by partial bandwidth

[0428] - Second channel measurement setting information by cell or by partial bandwidth

[0429] -An indicator for adding a cell group setting, or an indicator for instructing a cell group change (ReconfigurationWithSync), or an indicator for instructing a random access procedure (ReconfigurationWithSync or a newly defined indicator)

[0430] -An indicator (ReconfigurationWithSync or a newly defined indicator) that indicates whether to perform a random access procedure when activating a cell group and activate the cell group, or to activate the cell group without a random access procedure

[0431] RRM (radio resource management) setting information, frequency measurement setting information, separate RRM (radio resource management) setting information that must be applied or performed when a cell group is deactivated, or frequency measurement setting information (e.g., simplified frequency measurement setting information for battery saving (reduced or relaxed RRM setting information)

[0432] Configuration information for radio link monitoring (RLM), or configuration information for RLM that must be applied or performed when a cell group is deactivated. For example, configuration information for RLM, or configuration information for RLM that must be applied or performed when a cell group is deactivated, is configuration information for cell-based beams that a terminal must measure when a cell group is deactivated, or configuration information for beams per partial bandwidth, and includes beam-related configuration information (transmission configuration indication (TCI) state or quasi co-location (QCL)). Alternatively, configuration information for RLM, or configuration information for RLM that must be applied or performed when a cell group is deactivated, includes a timing advance (TA) value (or offset value) for synchronizing a base station downlink signal or a base station uplink signal, a timer (TAT: time alignment timer) indicating the validity of the TA value, or a timer value (TAT value). Alternatively, the configuration information for RLM, or the configuration information for RLM that must be applied or performed when a cell group is deactivated, includes synchronization signal block (SSB) configuration information that must be measured, channel state information reference signal (CSI-RS) configuration information, reference signal (RS) configuration information, and transmission resource information for reporting the result when a beam failure occurs (e.g., PUCCH configuration information (e.g., scheduling request (SR) information or specific transmission resource), or frequency transmission resource or time transmission resource). The configuration information also includes partial bandwidth configuration information (e.g., indicated by a partial bandwidth identifier) ​​that indicates in which partial bandwidth the RLM procedure is to be performed.Alternatively, when the cell group state is in the deactivated state, the UE performs the RLM procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) configured by the RRC message, and when activating the cell group, the UE quickly monitors the first activated partial bandwidth to be activated, thereby minimizing cell group activation delay. Alternatively, when the cell group state is set to the deactivated state (or the activated state), the UE performs the RLM procedure in the partial bandwidth that was last (or previously) activated before the cell group state was deactivated, and continues to maintain the connection state with the cell group (e.g., when partial bandwidth configuration information indicating which partial bandwidth to perform the RLM procedure in is not configured), or when activating the cell group, the UE performs the activation procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) configured by the RRC message. If partial bandwidth-related configuration information indicating which partial bandwidth to perform the RLM procedure on when activating a cell group is not configured, the UE performs the RLM procedure on the partial bandwidth that was activated last (or previously). The configuration information also includes beam-related configuration information (e.g., a partial bandwidth identifier, TCI state, or QCL configuration information) indicating which beam to perform the RLM procedure on. Alternatively, when the cell group state is in a deactivated state, the UE performs the RLM procedure on the beam configured by the RRC message (e.g., TCI state or QCL configuration information), or activates a beam, performs the RLM procedure, and minimizes cell group activation delay by quickly monitoring the beam to be activated when activating a cell group.Alternatively, if the cell group state is set to a deactivated state (or an activated state), the UE performs the RLM procedure in the beam that was last (or previously) activated before the cell group state was deactivated and continues to maintain a connection state with the cell group (e.g., if beam-related configuration information indicating which beam the RLM procedure is to be performed in is not configured), or when activating the cell group, the UE performs the activation procedure in the beam configured by the RRC message. If beam-related configuration information indicating which beam the RLM procedure is to be performed in is not configured when activating the cell group, the UE performs the RLM procedure in the beam that was last (or previously) activated.

[0433] -Configuration information for beam failure detection procedure, beam failure detection (BFD), or configuration information for BFD that must be applied or performed when a cell group is deactivated. For example, the configuration information for beam failure detection procedure, BFD, or configuration information for BFD that must be applied or performed when a cell group is deactivated is cell-based beam configuration information that a terminal must measure when a cell group is deactivated, or partial bandwidth-based beam configuration information, and includes beam-related configuration information (transmission configuration indication (TCI) state or quasi co-location (QCL)). Alternatively, the configuration information for beam failure detection procedure, BFD, or configuration information for BFD that must be applied or performed when a cell group is deactivated includes a timing advance (TA) value (or offset value) for synchronizing the downlink signal of a base station or the uplink signal of a base station, a timer (TAT: time alignment timer) indicating the validity of the TA value, or a timer value (TAT value). Alternatively, the beam failure detection procedure, configuration information for BFD, or configuration information for BFD that must be applied or performed when a cell group is deactivated, includes synchronization signal block (SSB) configuration information that must be measured, channel state information reference signal (CSI-RS) configuration information, reference signal (RS) configuration information, and transmission resource information that can report the results when a beam failure occurs (e.g., PUCCH configuration information (e.g., scheduling request (SR) information or specific transmission resource), or frequency transmission resource or time transmission resource). The configuration information also includes partial bandwidth configuration information (e.g., which can be indicated by a partial bandwidth identifier) ​​that indicates which partial bandwidth the beam failure detection procedure will be performed on.Alternatively, when the cell group state is in the deactivated state, the UE performs the beam failure detection procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) set by the RRC message, and when activating the cell group, the UE quickly monitors the first activated partial bandwidth that must be activated, thereby minimizing the cell group activation delay. Alternatively, when the cell group state is set to the deactivated state (or the activated state), the UE performs the beam failure detection procedure in the partial bandwidth that was last (or previously) activated before the cell group state was deactivated, and continues to maintain the connection state with the cell group (e.g., when partial bandwidth configuration information indicating which partial bandwidth the beam failure detection procedure is to be performed in is not set), or when activating the cell group, the UE performs the activation procedure in the first activated partial bandwidth (or the first activated downlink partial bandwidth (firstActiveDownlinkBWP-ID)) set by the RRC message. If partial bandwidth-related configuration information indicating which partial bandwidth to perform the beam failure detection procedure on when activating a cell group is not configured, the UE performs the beam failure detection procedure on the partial bandwidth that was activated last (or previously). The configuration information also includes beam-related configuration information (e.g., indicated by a partial bandwidth identifier, TCI state, or QCL configuration information) indicating which beam to perform the beam failure detection procedure on. Alternatively, when the cell group state is in an inactive state, the UE performs the beam failure detection procedure on the beam configured by the RRC message (e.g., TCI state or QCL configuration information), thereby minimizing cell group activation delay by quickly monitoring the beams that need to be activated when activating a cell group.Alternatively, if the cell group state is set to a deactivated state (or an activated state), the UE performs the beam failure detection procedure in the beam that was last (or previously) activated before the cell group state was deactivated and continues to maintain a connection state with the cell group (e.g., if beam-related configuration information indicating which beam to perform the beam failure detection procedure in is not configured), or if the cell group is activated, the UE performs the activation procedure in the beam configured by the RRC message. If beam-related configuration information indicating which beam to perform the beam failure detection procedure in is not configured when the cell group is activated, the UE performs the beam failure detection procedure in the beam that was last (or previously) activated.

[0434] -SDAP layer configuration information (sdap-config): The SDAP layer configuration information is configured for each bearer and includes the following information: The SDAP layer configuration information is configuration information that determines how to map a QoS flow to a bearer (DRB) when an NR base station or an E-UTRA base station is connected to a 5GC (5G core) or whether an uplink (or downlink) SDAP header is present.

[0435] --PDU session identifier (pdu-Session): The PDU session identifier indicates the PDU session of the QoS flow that is mapped to the bearer.

[0436] Downlink SDAP header presence indicator (sdap-HeaderDL): Indicates whether an SDAP header exists for the bearer's downlink data. The downlink SDAP header presence indicator value is not changed after the bearer is established.

[0437] --Indicator indicating whether an uplink SDAP header exists (sdap-HeaderUL): The indicator indicates whether an SDAP header exists or not for the uplink data of the bearer. If the bearer is set as the default bearer, the network sets the indicator indicating whether an SDAP header exists for the uplink data.

[0438] --Default bearer indicator (default DRB): Indicates whether the configured bearer (or DRB) is the default bearer for the PDU session. The indicator value indicating the default bearer is set to TRUE for only one bearer (or instance) among bearers (or instances) belonging to the same PDU session (or having the same PDU session identifier value), and is set to FALSE for the remaining bearers. In other words, only one default bearer is configured for one PDU session.

[0439] --Configuration information for adding QoS flow mapping information (mappedQoS-FlowsToAdd): Indicates a list of QFI identifiers (QFI: QoS flow identifier) ​​of uplink QoS flows of PDU sessions to be added and mapped to a bearer. One QFI identifier value is included and configured only once in the SDAP layer configuration information having the PDU session identifier value among all SDAP layer configuration information configured in the terminal. When configuring QoS flow remapping, the QFI identifier of the QoS flow to be remapped is included and configured only in the configuration information (mappedQoS-FlowsToAdd) that adds QoS flow mapping information of the SDAP layer configuration information corresponding to the new bearer (or the newly mapped bearer), and is not included in the configuration information (mappedQoS-FlowsToRelease) that releases QoS flow mapping information corresponding to the old bearer (or the previously mapped bearer).

[0440] --Configuration information for releasing QoS flow mapping information (mappedQoS-FlowsToRelease): Specifies a list related to the QFI identifier (QFI: QoS flow identifier) ​​of the QoS flow of the PDU session to be released from the existing QoS flow bearer-mapped to the bearer.

[0441] When the terminal receives the second RRC message (1k-20), the terminal reads and confirms the second RRC message or reads the information included in the second RRC message (e.g., the first RRC message included in the second RRC message), and the terminal configures, adds, modifies, resumes, suspends, or deactivates a dual connectivity technology or cell group (e.g., a secondary cell group). Also, if the second RRC message or the first RRC message includes a first indicator for triggering a random access procedure, the terminal triggers a random access procedure for the configured or indicated cell group or cell. When performing a random access procedure, if the RRC message contains random access information or if there is stored random access information, the UE performs the random access procedure (e.g., a non-contention-based random access procedure (e.g., 4-step random access or 2-step random access) based on the random access information stored or received in the RRC message, or based on system information. If there is no random access information in the RRC message, the UE performs the random access procedure (e.g., a contention-based random access procedure (e.g., 4-step random access or 2-step random access)). Alternatively, the UE monitors the PDCCH in an indicated or configured cell group or cell, and triggers and performs the random access procedure as indicated by the PDCCH. For example, a higher layer (e.g., RRC layer) transmits an indicator to a lower layer (e.g., MAC layer) to trigger a random access procedure.

[0442] 1K, 1k-40 is a diagram illustrating a problem that occurs in a terminal when a first RRC message or a second RRC message includes configuration information to deactivate a cell group (or a secondary cell group) of the terminal (e.g., setting the state of the cell group to a deactivated state) and configuration information of the SDAP layer to configure QoS flow remapping, and is transmitted to the terminal. Problems may also occur when the base station configures (e.g., sets to 1) a Reflective QoS flow to DRB mapping indication (RDI) value or a Reflective QoS indication (RQI) value in the SDAP header of downlink data for a deactivated (or deactivated) cell group, instructs reflective mapping, and configures QoS flow remapping.

[0443] In 1k-40, if a UE configured with dual connectivity technology receives a first RRC message or a second RRC message including configuration information to deactivate a cell group (or a secondary cell group) (e.g., setting the state of the cell group to a deactivated state), the UE performs a procedure to deactivate the cell group. The UE will no longer be able to transmit or receive data for the deactivated cell group (or via a bearer of the deactivated cell group). Meanwhile, if the first RRC message or the second RRC message includes configuration information to deactivate the UE's cell group (or a secondary cell group) (e.g., setting the state of the cell group to a deactivated state) and includes configuration information of the SDAP layer to configure QoS flow remapping for the deactivated cell group, the UE performs QoS flow remapping for the deactivated cell group. For example, when the configuration information (mappedQoS-FlowsToAdd) for adding QoS flow mapping information in the SDAP layer configuration information indicates a list of QFI (QoS flow identifier) ​​identifiers (QFI) of uplink QoS flows of PDU sessions to be additionally mapped to a new bearer (or a newly mapped bearer (1k-80)), it includes the QFI identifier (1k-45) of the QoS flow to be remapped for QoS flow remapping (1k-50). That is, the first QoS flow (1k-45) (QoS flow 3) mapped to the first bearer (1k-70) (old DRB) belonging to the deactivated cell group (SCG) is configured (or indicated) for remapping (1k-50) in the second bearer (1k-80) (new DRB) of the activated cell group (MCG).QoS flow remapping (1k-50) is performed by the base station setting the RDI (Reflective QoS flow to DRB mapping Indication) value or RQI (Reflective QoS indication) value in the SDAP header of the downlink data (e.g., setting it to 1), and instructing reflective mapping.

[0444] As described above, if QoS flow remapping (1k-50) is configured in the UE, the SDAP layer generates an end marker (1k-55) including a QFI corresponding to QoS flow (1k-45) (QoS flow 3) to be remapped to the SDAP control data (SDAP control PDU) in order to prevent out-of-order delivery at the receiving end caused by QoS flow remapping, and transmits it to the first bearer (1k-70) (old DRB). However, as described above, a problem occurs when the UE cannot transmit or receive data for the deactivated cell group (or via the bearer of the deactivated cell group), but an end marker is generated and must be transmitted via the bearer of the deactivated cell group. For example, the generation of the end marker may cause the UE to unnecessarily request the base station to reactivate a cell group that the base station has instructed to be deactivated, or may result in unnecessary signaling (e.g., an RRC message from the UE requesting activation of a cell group, an RRC message from the base station instructing reactivation, or an RRC message from the base station instructing re-deactivation). Also, the end marker may not be transmitted because the cell group has been deactivated.

[0445] Therefore, in the following disclosure, methods are proposed to solve the problems that may arise when QoS flow remapping is configured or indicated for a deactivated cell group, by applying one or more of the following methods, or by combining several methods to form a new method:

[0446] First method: When QoS flow remapping is required (or configured) for the UE or when QoS flow remapping is required for a bearer belonging to a cell group to be deactivated, an NR base station or E-UTRA base station connected to 5GC configures QoS flow remapping (e.g., QoS flow remapping by including SDAP layer configuration information in an RRC message and transmitting it to the UE, or QoS flow remapping via reflective mapping by setting the RDI field or RQI field in the SDAP header) in the UE before deactivating the cell group (e.g., SCG) (or before transmitting an RRC message including an indicator for deactivating the cell group). That is, when QoS flow remapping is required (or configured) for the UE or when QoS flow remapping is required for a bearer belonging to a cell group to be deactivated, neither an instruction nor a configuration for deactivating the cell group is configured in the RRC message (e.g., QoS flow remapping cannot be configured or is not allowed for the cell group to be deactivated or for a bearer belonging to the cell group).

[0447] According to one embodiment, when an RRC message (e.g., RRCReconfiguration) includes an indicator to deactivate a cell group (or sets the state of a cell group to deactivated), an NR base station or an E-UTRA base station connected to 5GC restricts the SDAP layer configuration information (PDU session identifier, indicator indicating the presence or absence of a downlink SDAP header (sdap-HeaderDL), indicator indicating the presence or absence of an uplink SDAP header (sdap-HeaderUL), indicator indicating a default bearer (default DRB), configuration information for adding QoS flow mapping information (mappedQoS-FlowsToAdd), or configuration information for releasing QoS flow mapping information (mappedQoS-FlowsToRelease)) or the RDI field (or RQI field) setting (e.g., set to 1) of the SDAP header to be absent, not included, not set, or not QoS flow remapping.

[0448] According to one embodiment, an NR base station or an E-UTRA base station connected to 5GC, when an RRC message (e.g., RRCReconfiguration) does not include an indicator to deactivate a cell group (or does not set the state of the cell group to deactivation), ensures that SDAP layer configuration information (PDU session identifier, indicator indicating the presence or absence of a downlink SDAP header (sdap-HeaderDL), indicator indicating the presence or absence of an uplink SDAP header (sdap-HeaderUL), indicator indicating a default bearer (default DRB), configuration information to add QoS flow mapping information (mappedQoS-FlowsToAdd) or configuration information to release QoS flow mapping information (mappedQoS-FlowsToRelease)), or an RDI field (or RQI field) setting (e.g., set to 1) in the SDAP header exists, is included, is set, or is QoS flow remapped.

[0449] According to one embodiment, an NR base station or an E-UTRA base station connected to 5GC restricts an RRC message (e.g., RRCReconfiguration) not to include an indicator for deactivating a cell group (or not to set the state of a cell group to inactive) if SDAP layer configuration information (PDU session identifier, indicator indicating the presence or absence of a downlink SDAP header (sdap-HeaderDL), indicator indicating the presence or absence of an uplink SDAP header (sdap-HeaderUL), indicator indicating a default bearer (default DRB), configuration information for adding QoS flow mapping information (mappedQoS-FlowsToAdd), configuration information for releasing QoS flow mapping information (mappedQoS-FlowsToRelease), or an RDI field (or RQI field) setting (e.g., set to 1) in the SDAP header exists, is included, or is set, or if QoS flow remapping is configured.

[0450] According to one embodiment, an NR base station or an E-UTRA base station connected to a 5GC configures an RRC message (e.g., RRCReconfiguration) to include an indicator to deactivate a cell group (or set the state of the cell group to deactivated) if the SDAP layer configuration information (PDU session identifier, indicator indicating the presence or absence of a downlink SDAP header (sdap-HeaderDL), indicator indicating the presence or absence of an uplink SDAP header (sdap-HeaderUL), indicator indicating a default bearer (default DRB), configuration information to add QoS flow mapping information (mappedQoS-FlowsToAdd), configuration information to release QoS flow mapping information (mappedQoS-FlowsToRelease), or the RDI field (or RQI field) setting (e.g., set to 1) of the SDAP header does not exist, is not included, is not set, or QoS flow remapping is not performed.

[0451] Method 2: When QoS flow remapping is required (or configured) for the UE, or when QoS flow remapping is required for a bearer belonging to a cell group to be deactivated, an NR base station or E-UTRA base station connected to 5GC deactivates a cell group (e.g., SCG) (or transmits an RRC message including an indicator for deactivating the cell group), and configures QoS flow remapping (e.g., including SDAP layer configuration information in the RRC message and transmitting it to the UE, setting QoS flow remapping or the RDI field or RQI field in the SDAP header, and QoS flow remapping via reflective mapping) for the UE, the SDAP layer of the UE does not generate an end marker for a bearer of a cell group that is deactivated due to the first condition. That is, the SDAP layer of the UE generates an end marker for a bearer that does not belong to a cell group that is deactivated due to the first condition, or when performing QoS flow remapping if the cell group to which the bearer belongs is not deactivated.The first condition may also include a condition that, when QoS flow remapping (uplink QoS flow and bearer mapping) is configured for any QoS flow (or when the RDI field (or RQI field) in the downlink SDAP header of the received data is set to 1), if the SDAP layer has already been established and there is no mapping between the QoS flow and the bearer stored for that QoS flow, and a default bearer is configured, or if the cell group to which the QoS flow (or bearer) belongs is not deactivated, an end marker is generated and transmitted to the default bearer. Alternatively, the first condition may include a condition that, when QoS flow remapping (uplink QoS flow and bearer mapping) is configured for any QoS flow (or when the RDI field (or RQI field) in the downlink SDAP header of the received data is set to 1), if the mapping between the QoS flow and the bearer stored for that QoS flow differs from the mapping between the QoS flow and the bearer newly configured by an RRC message, an uplink SDAP header exists, or if a QoS If the cell group to which the flow (or bearer) belongs is not deactivated, an end marker is generated and transmitted to the bearer corresponding to the previously stored QoS flow and bearer mapping.

[0452] In addition, in the configuration information of the SDAP layer, the default bearer is used as a bearer for transmitting data related to an uplink QoS flow for which there is no (or no) mapping between the QoS flow and the bearer. Therefore, if the default bearer is configured as a bearer belonging to a deactivated cell group, data cannot be transmitted or a request procedure to activate the cell group is performed unnecessarily.

[0453] Therefore, the present disclosure proposes restricting the default bearer set as SDAP layer configuration information so that it cannot be set as a bearer belonging to a deactivated cell group. Alternatively, it proposes setting the default bearer set as SDAP layer configuration information as a bearer belonging to a non-deactivated cell group. Alternatively, an NR base station or an E-UTRA base station connected to 5GC may transmit another RRC message including SDAP layer configuration information to the terminal before transmitting an RRC message to deactivate the cell group to the terminal, thereby changing or reconfiguring the default bearer to a bearer belonging to a non-deactivated cell group. Alternatively, an NR base station or an E-UTRA base station connected to 5GC may transmit an RRC message to the terminal to deactivate the cell group, while including SDAP layer configuration information in the RRC message, and transmit the RRC message to the terminal, thereby changing or reconfiguring the default bearer to a bearer belonging to a non-deactivated cell group.

[0454] In the following disclosure, a first embodiment of a terminal operation taking dual connectivity technology configuration information into consideration when receiving an RRC message (e.g., an RRC Reconfiguration message) is proposed. In this embodiment, a procedure is proposed that enables a terminal to activate a cell group without a random access procedure (RACH less activation) when activating, adding, or modifying a cell group.

[0455] If the UE receives an RRCReconfiguration message, the UE performs the following procedure.

[0456] 1> If the UE's MCG (or MN (master node)) is configured for LTE (E-UTRA) and its SCG (or SN (secondary node)) is configured for NR (i.e., E-UTRAnr-secondarycellgroupConfig is configured), or if the UE is configured for (NG)EN-DC (Next Generation E-UTRA NR-Dual connectivity connected to 5GC),

[0457] 2> If the RRCReconfiguration message is received via the E-UTRA RRC message in the MobilityFromNRCommand message (a message instructing handover from NR to (NG)EN-DC),

[0458] 3> In the message, if the reconfigurationWithSync configuration information is included in the spCellConfig of the SCG or the cell group state of the SCG is not set to the inactive state,

[0459] 4> The terminal performs (or triggers or initiates) a random access procedure for the SpCell (or SCG or PSCell).

[0460] 4> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure is performed after the terminal determines whether or not to perform a random access procedure, triggers the random access procedure, successfully completes the random access procedure (or after completion), activates the cell group without a random access procedure, or successfully activates the cell group without a random access procedure (e.g., successfully receives a PDCCH or receives transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). Alternatively, a partial MAC reset is performed instead of the MAC layer initialization procedure. The MAC layer initialization procedure or partial MAC layer initialization procedure will be described in detail below in this disclosure.

[0461] 3> Otherwise, if the cell group state of the SCG is not set to inactive, or a new indicator (e.g., RACH-less indication) is included in the message indicating that the random access procedure should not be performed, or if the reconfigurationWithSync configuration information is not included in the spCellConfig of the SCG in the message,

[0462] 4> The terminal does not perform (or trigger or initiate) a random access procedure for the SpCell (or SCG or PSCell).

[0463] 4> The terminal activates the SpCell without a random access procedure, or starts PDCCH monitoring or PDSCH reception for the SpCell.

[0464] 4> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure is performed after the terminal determines whether or not to perform a random access procedure, triggers the random access procedure, successfully completes the random access procedure (or after completion), activates the cell group without a random access procedure, or successfully activates the cell group without a random access procedure (e.g., successfully receives a PDCCH or receives transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group or PTAG (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). Alternatively, instead of the MAC layer initialization procedure, a partial MAC reset is performed. The MAC layer initialization procedure or partial MAC layer initialization procedure will be described in detail below in this disclosure. 3> Otherwise (else),

[0465] 4> Complete the terminal execution procedure.

[0466] 1> If the UE's MCG (or MN (master node)) is configured to NR and its SCG (or SN (secondary node)) is configured to NR (i.e., E-UTRA nr-secondarycellgroupConfig is configured), or the UE is configured to NR-DC (NR-Dual connectivity connected to 5GC), or the UE receives an RRCReconfiguration message via SRB1 in the nr-SCG of mrdc-secondary cell group configuration information, or receives mrdc-secondary cell group configuration information via SRB1 in an RRCReconfiguration or RRCResume message,

[0467] 2> In the message, if the reconfigurationWithSync configuration information is included in the spCellConfig of the nr-SCG or the cell group state of the SCG is not set to the inactive state,

[0468] 3> The terminal performs (or triggers or initiates) a random access procedure for the SpCell (or SCG or PSCell).

[0469] 3> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure is performed after the terminal determines whether or not to perform a random access procedure, triggers the random access procedure, successfully completes the random access procedure (or after completion), activates the cell group without a random access procedure, or successfully activates the cell group without a random access procedure (e.g., successfully receives a PDCCH or receives transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group or PTAG (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). Alternatively, a partial MAC reset is performed instead of the MAC layer initialization procedure. The MAC layer initialization procedure or partial MAC layer initialization procedure will be described in detail below in this disclosure.

[0470] 2> Otherwise, if the cell group state of the SCG is not set to the deactivated state, or a new indicator (e.g., RACH-less indication) is included in the message indicating that the random access procedure should not be performed, or if the reconfigurationWithSync configuration information is not included in the spCellConfig of the SCG in the message,

[0471] 3> The terminal does not perform (or trigger or initiate) a random access procedure for the SpCell (or SCG or PSCell).

[0472] 3> The terminal activates the SpCell without a random access procedure, or starts PDCCH monitoring or PDSCH reception for the SpCell.

[0473] 3> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure is performed after the terminal determines whether or not to perform a random access procedure, triggers the random access procedure, successfully completes the random access procedure (or after completion), activates the cell group without a random access procedure, or successfully activates the cell group without a random access procedure (e.g., successfully receives a PDCCH or receives transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group or PTAG (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). Alternatively, a partial MAC reset is performed instead of the MAC layer initialization procedure. The MAC layer initialization procedure or partial MAC layer initialization procedure will be described in detail below in this disclosure.

[0474] 2> Otherwise (else),

[0475] 3> Complete the terminal execution procedure.

[0476] 1> In the message, if the reconfigurationWithSync configuration information is included in the spCellConfig of the MCG or SCG, and if the MAC layer of the NR cell group successfully completes the triggered random access procedure,

[0477] 2> Stop the first timer (T304) for the cell group (or if the timer is running).

[0478] 2> Stop the second timer (T310) associated with the cell group or source SpCell (or if the timer is running).

[0479] -When the message includes reconfigurationWithSync and the terminal performs a reconfiguration procedure (reconfiguration with Sync) to synchronize, the following procedure is performed.

[0480] 1> If a DAPS (dual active protocol stack) bearer is not configured, or the state of the cell group (or SCG) is not set to a deactivated state, or RLM-related configuration or beam failure detection-related configuration information for the deactivated cell group is not configured (if the state of the cell group is set to a deactivated state, the second timer continues to run, the RLM procedure is performed, and early cell group activation is supported), or if this procedure is not performed for the deactivated cell group (or SCG),

[0481] 2> Stop the second timer (T310) associated with the cell group or SpCell (or if the timer is running).

[0482] 1> Stop the third timer (T312) for the cell group or SpCell (or if the timer is running). 1> If the state of the cell group (or SCG) is not set to the inactive state or this procedure is not performed for a deactivated cell group (or SCG),

[0483] 2> Set the first timer (T304) value included in the reconfigurationWithSync setting information of the message, and start the first timer (T304) related to the SpCell (PCell of the MCG or PSCell of the SCG).

[0484] As proposed in the present disclosure, if RLM-related configuration information or beam presence detection-related configuration information is configured for a deactivated cell group (or SCG) in an RRC message (e.g., an RRC Reconfiguration message), the terminal performs a radio link failure detection procedure as follows.

[0485] 1> If the cell group state is set to a deactivated state (or a beam failure detection procedure or RLM procedure is set for a deactivated cell group), or if an indication that synchronization is not achieved for an SpCell is received from a lower layer a predetermined number of times (e.g., N310 value), a second timer (T310) for the SpCell is started (the second timer is stopped if it is running when the cell group state is activated, set to activated, or not set to deactivated, or when a random access procedure is initiated or performed for the SpCell. Also, if the second timer expires, a radio connection failure is declared to have occurred for the cell group).

[0486] 1> If a DAPS bearer is established, or an indication that synchronization is not achieved for the source SpCell is received from a lower layer a predetermined number of times (e.g., N310 value), or if the first timer is running, start the second timer (T310) for the source SpCell.

[0487] 1> If an indication that the SpCell is out of synchronization is received from the lower layer for a predetermined number of times (e.g., N310 value), or if the first timer (T304) or the fourth timer is not running, start the second timer (T310) associated with the source SpCell.

[0488] In the following of this disclosure, a second embodiment of a terminal operation taking dual connectivity technology configuration information into consideration when receiving an RRC message (e.g., an RRC Reconfiguration message) is proposed. In this embodiment, when the terminal activates, adds, or modifies a cell group, a procedure is proposed to activate the cell group without a random access procedure (RACH less activation).

[0489] If the UE receives an RRCReconfiguration message, the UE performs the following procedure.

[0490] 1> If the UE's MCG (or MN (master node)) is configured for LTE (E-UTRA) and its SCG (or SN (secondary node)) is configured for NR (i.e., E-UTRAnr-secondarycellgroupConfig is configured), or if the UE is configured for (NG)EN-DC (Next Generation E-UTRA NR-Dual connectivity connected to 5GC),

[0491] 2> If the RRCReconfiguration message is received via an E-UTRA RRC message in a MobilityFromNRCommand message (a message instructing handover from NR to (NG)EN-DC),

[0492] 3> In the message, if the reconfigurationWithSync setting information is included in the spCellConfig of the SCG, the cell group state of the SCG is not set to the deactivated state, the TAT (time alignment timer) timer (a timer that determines the validity of the TA (timing advance) value for synchronizing the terminal and the base station) running in the MAC layer is not running (or expires, or an indication that it has expired is received from a lower layer), an indication that a beam failure has been detected is received from a lower layer (or a beam failure occurs), a beam failure detection procedure or an RLM procedure related to the deactivated cell group is not configured, or a radio connection failure procedure is detected in the RLM procedure (or the second timer (T310) expires, or the radio connection with the SCG is not valid),

[0493] 4> The terminal performs (or triggers or initiates) a random access procedure for the SpCell (or SCG or PSCell).

[0494] 4> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure is performed after the terminal determines whether or not to perform a random access procedure, triggers the random access procedure, successfully completes the random access procedure (or after completion), activates the cell group without a random access procedure, or successfully activates the cell group without a random access procedure (e.g., successfully receives a PDCCH or receives transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group or PTAG (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). Alternatively, a partial MAC reset is performed instead of the MAC layer initialization procedure. The MAC layer initialization procedure or partial MAC layer initialization procedure will be described in detail below in this disclosure.

[0495] 3> Otherwise, if (else if) the cell group state of the SCG is not set to a deactivated state, or a new indicator (e.g., RACH-less indication) is included in the message and instructs not to perform the random access procedure, or the TAT (time alignment timer) timer (a timer that determines the validity of the TA (timing advance) value for synchronizing the terminal and the base station) running in the MAC layer is running (or has not expired, or an indication that it has expired has not been received from a lower layer), or an indication that a beam failure has been detected has not been received from a lower layer (or a beam failure has not occurred), or a beam failure detection procedure or RLM procedure related to the deactivated cell group is configured, or a radio connection failure procedure has not been detected in the RLM procedure (or the second timer (T310) has not expired, or the radio connection of the SCG was valid), or if the reconfigurationWithSync configuration information is not included in the spCellConfig of the SCG in the message,

[0496] 4> The terminal does not perform (or trigger or initiate) a random access procedure for the SpCell (or SCG or PSCell).

[0497] 4> The terminal activates the SpCell without a random access procedure, or starts PDCCH monitoring or PDSCH reception for the SpCell.

[0498] 4> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure is performed after the terminal determines whether or not to perform a random access procedure, triggers the random access procedure, successfully completes the random access procedure (or after completion), activates the cell group without a random access procedure, or successfully activates the cell group without a random access procedure (e.g., successfully receives a PDCCH or receives transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group or PTAG (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). Alternatively, a partial MAC reset is performed instead of the MAC layer initialization procedure. The MAC layer initialization procedure or partial MAC layer initialization procedure will be described in detail below in this disclosure.

[0499] 3> Otherwise, if (else if) the cell group state of the SCG is not set to a deactivated state, or a new indicator (e.g., RACH-less indication) is included in the message and instructs not to perform the random access procedure, or the TAT (time alignment timer) timer (a timer that determines the validity of the TA (timing advance) value for synchronizing the terminal and the base station) running in the MAC layer is not running (or expires, or an indication that it has expired is received from a lower layer), or an indication that a beam failure has been detected is received from a lower layer (or a beam failure occurs), or a beam failure detection procedure or RLM procedure related to the deactivated cell group is not configured, or a radio connection failure procedure is detected in the RLM procedure (or the second timer (T310) expires, or the radio connection with the SCG is not valid), or if the reconfigurationWithSync configuration information is not included in the spCellConfig of the SCG in the message,

[0500] 4> The terminal performs (or triggers or initiates) a random access procedure for the SpCell (or SCG or PSCell).

[0501] 4> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure is performed after the terminal determines whether or not to perform a random access procedure, triggers the random access procedure, successfully completes the random access procedure (or after completion), activates the cell group without a random access procedure, or successfully activates the cell group without a random access procedure (e.g., successfully receives a PDCCH or receives transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group or PTAG (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). Alternatively, a partial MAC reset is performed instead of the MAC layer initialization procedure. The MAC layer initialization procedure or partial MAC layer initialization procedure will be described in detail below in this disclosure.

[0502] 3> Otherwise (else),

[0503] 4> Complete the terminal execution procedure.

[0504] 1> If the UE's MCG (or MN (master node)) is configured to NR and its SCG (or SN (secondary node)) is configured to NR (i.e., E-UTRA nr-secondarycellgroupConfig is configured), or the UE is configured to NR-DC (NR-Dual connectivity connected to 5GC), or the UE receives an RRCReconfiguration message via SRB1 in the nr-SCG of mrdc-secondary cell group configuration information, or receives mrdc-secondary cell group configuration information via SRB1 in an RRCReconfiguration or RRCResume message,

[0505] 2> In the message, if the reconfigurationWithSync setting information is included in the spCellConfig of the nr-SCG, or the cell group state of the SCG is not set to the deactivated state, or the TAT (time alignment timer) timer (a timer that determines the validity of the TA (timing advance) value for synchronizing the terminal and the base station) running in the MAC layer is not running (or expires, or an indication that it has expired is received from a lower layer), or an indication that a beam failure has been detected is received from a lower layer (or a beam failure occurs), or a beam failure detection procedure or RLM procedure related to the deactivated cell group is not configured, or a radio connection failure procedure is detected in the RLM procedure (or the second timer (T310) expires, or the radio connection with the SCG is not valid),

[0506] 3> The terminal performs (or triggers or initiates) a random access procedure for the SpCell (or SCG or PSCell).

[0507] 3> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure is performed after the terminal determines whether or not to perform a random access procedure, triggers the random access procedure, successfully completes the random access procedure (or after completion), activates the cell group without a random access procedure, or successfully activates the cell group without a random access procedure (e.g., successfully receives a PDCCH or receives transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group or PTAG (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). Alternatively, a partial MAC reset is performed instead of the MAC layer initialization procedure. The MAC layer initialization procedure or partial MAC layer initialization procedure will be described in detail below in this disclosure.

[0508] 2> Otherwise, if (else if) the cell group state of the SCG is not set to a deactivated state, or a new indicator (e.g., RACH-less indication) is included in the message and instructs not to perform the random access procedure, or the TAT (time alignment timer) timer (a timer that determines the validity of the TA (timing advance) value for synchronizing the terminal and the base station) running in the MAC layer is running (or has not expired, or an indication that it has expired has not been received from a lower layer), or an indication that a beam failure has been detected has not been received from a lower layer (or a beam failure has not occurred), or a beam failure detection procedure or RLM procedure related to the deactivated cell group is configured, or if the reconfigurationWithSync setting information is not included in the spCellConfig of the SCG in the message, or a radio connection failure procedure has not been detected in the RLM procedure (or if the second timer (T310) has not expired, or if the radio connection with the SCG is valid),

[0509] 3> The terminal does not perform (or trigger or initiate) a random access procedure for the SpCell (or SCG or PSCell).

[0510] 3> The terminal activates the SpCell without a random access procedure, or starts PDCCH monitoring or PDSCH reception for the SpCell.

[0511] 4> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure is performed after the terminal determines whether or not to perform a random access procedure, triggers the random access procedure, successfully completes the random access procedure (or after completion), activates the cell group without a random access procedure, or successfully activates the cell group without a random access procedure (e.g., successfully receives a PDCCH or receives transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group or PTAG (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). Alternatively, a partial MAC reset is performed instead of the MAC layer initialization procedure. The MAC layer initialization procedure or partial MAC layer initialization procedure will be described in detail below in this disclosure.

[0512] 2> Otherwise, if (else if) the cell group state of the SCG is not set to a deactivated state, or a new indicator (e.g., RACH-less indication) is included in the message and instructs not to perform the random access procedure, or the TAT (time alignment timer) timer (a timer that determines the validity of the TA (timing advance) value for synchronizing the terminal and the base station) running in the MAC layer is not running (or expires, or an indication that it has expired is received from a lower layer), or an indication that a beam failure has been detected is received from a lower layer (or a beam failure occurs), or a beam failure detection procedure or RLM procedure related to the deactivated cell group is not configured, or a radio connection failure procedure is detected in the RLM procedure (or the second timer (T310) expires, or the radio connection with the SCG is not valid), or if the reconfigurationWithSync configuration information is not included in the spCellConfig of the SCG in the message,

[0513] 3> The terminal performs (or triggers or initiates) a random access procedure for the SpCell (or SCG or PSCell).

[0514] 3> If a cell group (e.g., a secondary cell group) is configured (or instructed) to be activated (or if the state of the cell group is not set to a deactivated state), or if the previous state of the cell group was a deactivated state, or if the terminal was in a connected mode, the terminal initializes the MAC layer (MAC reset). The MAC layer initialization (MAC reset) procedure can be performed after the terminal determines whether or not to perform a random access procedure, after triggering the random access procedure, when the random access procedure is successfully completed (or after completion), or when the terminal activates a cell group without a random access procedure, or when the terminal successfully activates a cell group without a random access procedure (e.g., successful reception of a PDCCH or reception of transmission resources). This is because if the MAC layer is initialized first when activating a cell group, the TAT (time alignment timer) associated with the cell group or PTAG (or PSCell) is considered to have expired, and the procedure for activating the cell group cannot be performed without the random access procedure proposed in this disclosure (i.e., the cell group can be activated without the random access procedure only if the TAT timer is running). ...

Claims

1. 1. A method for performing dual access by a first base station in a wireless communication system, comprising: sending a request message for the dual access to a second base station; receiving a response message from the second base station, the response message including configuration information of a second cell group (SCG) for the dual access; identifying whether the response message includes information regarding the status of the SCG; transmitting a radio resource control (RRC) message to a terminal, the RRC message including configuration information of the SCG and information about a state of the SCG; A method characterized in that the SCG configuration information includes information that does not perform QoS flow remapping on a data radio bearer (DRB) associated with the SCG if the RRC message includes an indicator indicating deactivation of the SCG.

2. The information about the state of the SCG includes a current state of the SCG; 2. The method of claim 1, wherein the configuration information of the SCG includes information that indicates that the QoS flow remapping is not performed on the DRB associated with the SCG if the current state of the SCG is deactivated.

3. The information about the state of the SCG includes an indicator indicating deactivation of the SCG; The method of claim 1 , wherein the configuration information of the SCG includes information that does not perform the QoS flow remapping on the DRB associated with the SCG.

4. The step of transmitting the RRC message to the terminal comprises: transmitting configuration information for the QoS flow remapping to the terminal; and transmitting the RRC message to the terminal, the RRC message including information about a state of the SCG.

5. sending an RRC message including configuration information of an SDAP layer to the terminal; transmitting the RRC message to the terminal, the RRC message including an indicator indicating deactivation of the SCG; The method of claim 1, wherein the RRC message including the SDAP layer configuration information includes default bearer configuration information.

6. The method of claim 5, wherein the default bearer configuration information resets the default bearer to a bearer included in a deactivated cell group.

7. 1. A method for a terminal to perform dual access in a wireless communication system, comprising: receiving a radio resource control (RRC) message including configuration information of a second cell group (SCG) and information regarding a state of the SCG based on a message from a second base station constituting the second cell group; transmitting an RRC response message including information on whether the SCG configuration is successful; A method characterized in that the SCG configuration information includes information that does not perform QoS flow remapping on a data radio bearer (DRB) associated with the SCG if the RRC message includes an indicator indicating deactivation of the SCG.

8. The information about the state of the SCG includes a current state of the SCG; The method of claim 7, wherein the configuration information of the SCG includes information that does not perform the QoS flow remapping on the DRB associated with the SCG if the current state of the SCG is deactivated.

9. The information about the state of the SCG includes an indicator indicating deactivation of the SCG; The method of claim 7 , wherein the configuration information of the SCG includes information that does not perform the QoS flow remapping on the DRB associated with the SCG.

10. The step of receiving an RRC message comprises: receiving configuration information for the QoS flow remapping from a first base station; and receiving the RRC message from the first base station, the RRC message including information regarding the status of the SCG.

11. receiving an RRC message from a first base station, the RRC message including configuration information for an SDAP layer; receiving the RRC message from the first base station, the RRC message including an indicator indicating deactivation of the SCG; The method of claim 7, wherein the RRC message including the SDAP layer configuration information includes default bearer configuration information.

12. The method of claim 11, wherein the default bearer configuration information resets the default bearer to a bearer included in a deactivated cell group.

13. 1. A first base station for implementing dual access in a wireless communication system, comprising: The first base station a transmitter / receiver; at least one processor coupled to the transceiver; The at least one processor Sending a request message for the dual access to a second base station; receiving a response message from the second base station, the response message including configuration information regarding a second cell group (SCG) for the dual access; Identifying whether the response message includes information about the status of the SCG; Transmitting a radio resource control (RRC) message including configuration information of the SCG and information about the status of the SCG to a terminal; The first base station is characterized in that the SCG configuration information includes information that does not perform QoS flow remapping on a data radio bearer (DRB) associated with the SCG when the RRC message includes an indicator indicating deactivation of the SCG.

14. The information about the state of the SCG includes a current state of the SCG; Furthermore The first base station of claim 13, characterized in that the configuration information of the SCG includes the information that does not perform the QoS flow remapping on the DRB associated with the SCG when the current state of the SCG is deactivated.

15. The information about the state of the SCG includes an indicator indicating deactivation of the SCG; The first base station according to claim 13, wherein the configuration information of the SCG includes information not to perform the QoS flow remapping on the DRB associated with the SCG.

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