Method and device for performing cell reselection for UE in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for providing a higher data transmission rate than the previous 4G communication system, such as LTE. A method for operating a UE according to an embodiment of the present disclosure may comprise the steps of: receiving a radio resource control (RRC) connection release message from a base station; receiving, from the base station, system information comprising cell reselection-related configuration information of a UE supporting LR; determining whether a cell supporting a low power wake-up signal (LP-WUS) satisfies a cell selection criterion on the basis of the cell reselection-related configuration information of the UE supporting LR; and according to the determination, performing cell reselection for the cell supporting the LP-WUS.

Description

Method and device for performing cell reselection of a terminal in a wireless communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method and device for performing cell reselection in a terminal supporting a low-power wake-up receiver in a wireless communication system.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] Embodiments of the present disclosure provide a method and apparatus for a terminal supporting a low-power wake-up receiver to perform cell reselection in order to reduce power consumption of the terminal in a wireless communication system.

[0009] The present disclosure may provide, according to one embodiment, an operating method of a user equipment (UE) supporting a low power wake-up receiver (LR) in a wireless communication system. The operating method may include: receiving, from a base station, an RRC (Radio Resource Control) disconnection message; receiving, from the base station, system information including cell reselection-related configuration information of a UE supporting LR; determining, based on the cell reselection-related configuration information of the UE supporting LR, whether a cell supporting a low power wake-up signal (LP-WUS) satisfies a cell selection criterion; and performing cell reselection on the cell supporting the LP-WUS based on the determination.

[0010] According to one embodiment of the present disclosure, cell reselection related configuration information of a UE supporting LR may include a minimum signal reception level offset value for a cell supporting the LP-WUS; and a minimum signal quality level offset value for a cell supporting the LP-WUS.

[0011] According to one embodiment of the present disclosure, a minimum signal reception level offset value for a cell supporting LP-WUS and a minimum signal quality level offset value for a cell supporting LP-WUS may be signaled for each cell within each frequency and may be signaled together with a physical cell identifier (PCI).

[0012] According to one embodiment of the present disclosure, the method of operating the UE may further include a step of determining a serving frequency with the highest cell reselection priority when the UE supporting LR selects or reselects a cell supporting the LP-WUS.

[0013] According to one embodiment of the present disclosure, the operating method of the UE may further include a step of determining a serving frequency as the highest cell reselection priority when the cell reselection-related configuration information of the UE supporting the LR includes an indicator indicating that the serving frequency supports the LP-WUS.

[0014] According to one embodiment of the present disclosure, the RRC connection release message may include an indicator indicating that, when selecting or reselecting a cell supporting the LP-WUS, the frequency to which the corresponding cell belongs is to be determined as the highest cell reselection priority. According to one embodiment of the present disclosure, the operating method of the UE may further include a step of determining the serving frequency as the highest cell reselection priority based on the indicator.

[0015] According to one embodiment of the present disclosure, cell reselection-related configuration information of a UE supporting LR may include a list of allowed cells. According to one embodiment of the present disclosure, the operating method of the UE may further include a step of considering only cells included in the list of allowed cells as candidate cells for cell reselection.

[0016] According to one embodiment of the present disclosure, cell reselection-related configuration information of a UE supporting LR may include a list of excluded cells. According to one embodiment of the present disclosure, the operating method of the UE may further include a step of excluding cells included in the excluded cell list from candidate cells for cell reselection.

[0017] According to one embodiment of the present disclosure, cell reselection-related configuration information of a UE supporting LR may include an offset value between the serving cell and a neighboring cell supporting LP-WUS within the intra-frequency to which the serving cell belongs. The offset value may be used to derive a rank for each cell.

[0018] According to one embodiment of the present disclosure, cell reselection-related configuration information of a UE supporting LR may include an offset value between the serving cell and a neighboring cell supporting LP-WUS within a different frequency (inter-frequency) from the serving cell. The offset value may be used to derive a rank per cell.

[0019] According to one embodiment of the present disclosure, the RRC connection release message may include an indicator indicating to apply a frequency-specific cell reselection priority value supporting LP-WUS or a frequency-specific cell reselection priority value supporting LP-WUS included in the system information. According to one embodiment of the present disclosure, the operating method of the UE may further include a step of determining a cell reselection priority based on the frequency-specific cell reselection priority value supporting LP-WUS included in the RRC connection release message or the indicator.

[0020] According to one embodiment of the present disclosure, cell reselection-related configuration information of a UE supporting LR may include a frequency-specific cell reselection priority value supporting LP-WUS. According to one embodiment of the present disclosure, the operating method of the UE may further include a step of determining a cell reselection priority based on the frequency-specific cell reselection priority value supporting LP-WUS.

[0021] According to one embodiment of the present disclosure, the method of operating the UE may further include the step of transmitting a UE capability information message to the base station. The UE capability information message may include at least one of an indicator indicating whether LR is supported or an indicator indicating that reselection to a cell supporting the LP-WUS can be performed.

[0022] The present disclosure may provide a user equipment (UE) supporting a low power wake-up receiver (LR) in a wireless communication system according to one embodiment. The UE according to one embodiment may include a memory storing one or more commands; and at least one processor. The at least one processor may, by executing one or more commands, receive an RRC (Radio Resource Control) disconnection message from a base station; receive system information including cell reselection-related configuration information of a UE supporting LR from the base station; determine whether a cell supporting a low power wake-up signal (LP-WUS) satisfies a cell selection criterion based on the cell reselection-related configuration information of the UE supporting LR; and perform cell reselection on the cell supporting the LP-WUS based on the determination.

[0023] The present disclosure may provide a base station in a wireless communication system according to one embodiment. The base station according to one embodiment may include a memory storing one or more commands; and at least one processor. The at least one processor may transmit an RRC (Radio Resource Control) disconnection message to a user equipment (UE) supporting a low power wake-up receiver (LR) by executing one or more commands; and transmit system information including cell reselection-related configuration information of the UE supporting LR to the UE. The cell reselection-related configuration information of the UE supporting LR may be used by the UE to determine whether a cell supporting a low power wake-up signal (LP-WUS) satisfies a cell selection criterion.

[0024] Through embodiments of the present disclosure, a terminal supporting a low-power wake-up receiver (LR) can reduce power consumption by performing cell reselection by determining the priority of a cell supporting a low-power wake-up signal (LP-WUS).

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

[0026] FIG. 1b is a diagram illustrating a wireless protocol structure in an LTE system according to one embodiment.

[0027] FIG. 1c is a diagram illustrating the structure of a next-generation wireless communication system according to one embodiment.

[0028] FIG. 1d is a diagram illustrating a wireless protocol structure of a next-generation wireless communication system according to one embodiment.

[0029] FIG. 1e is a diagram for explaining a method for a terminal in an RRC idle mode (RRC_IDLE) or an RRC inactive state (RRC_INACTIVE) to perform a cell reselection evaluation procedure in a next-generation wireless communication system according to one embodiment.

[0030] FIG. 1f is a diagram illustrating a method for a terminal supporting a low-power wake-up receiver to perform cell reselection in a next-generation wireless communication system according to one embodiment.

[0031] FIG. 1g is a diagram for explaining a method for a terminal supporting a low-power wake-up receiver to perform cell reselection in a next-generation wireless communication system according to one embodiment.

[0032] Figure 1h is a block diagram of a terminal according to one embodiment.

[0033] FIG. 1i is a block diagram of a base station according to one embodiment.

[0034] The operating principles of the present disclosure are described in detail below with reference to the attached drawings. In the following description of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0035] In the following description of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Hereinafter, embodiments of the present disclosure will be described with reference to the attached drawings.

[0036] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are provided for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0037] Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal (User Equipment, UE) may include an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, the downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and the uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station.

[0038] In addition, although the LTE or LTE-A system may be described below as an example, embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in a system to which embodiments of the present disclosure may be applied, and the 5G described below may be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications within a range that does not significantly deviate from the scope of the present disclosure, as determined by a person having skilled technical knowledge.

[0039] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0040] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order depending on the corresponding function. In this case, the term '~unit' used in the present embodiment means software or a hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the '~unit' may perform certain roles. However, the '~unit' is not limited to software or hardware. The '~unit' may be configured to be on an addressable storage medium and may be configured to execute one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~ units' may be implemented to reproduce one or more CPUs within a device or a secure multimedia card. Also, in an embodiment, the '~ unit' may include one or more processors.

[0041] For the convenience of explanation below, this disclosure uses terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard (e.g., 3GPP Technical Specification 36 series). However, this disclosure is not limited to the above terms and names, and may be equally applied to systems conforming to other standards. For example, this disclosure may also be applied to the 3GPP 5GS / NR (5th generation mobile communication standard) standard (e.g., 3GPP Technical Specification 38 series), NR-Advance, 6th generation mobile communication technology (6G), or next-generation mobile communication systems with similar technical backgrounds developed in the future. In this disclosure, eNB may be used interchangeably with gNB for the convenience of explanation. That is, a base station described as an eNB may represent a gNB.

[0042] FIG. 1a is a diagram illustrating the structure of an LTE system according to one embodiment.

[0043] Referring to FIG. 1a, as illustrated, the wireless access network of the LTE system is composed of next-generation base stations (Evolved Node Bs, hereinafter referred to as ENBs, Node Bs or base stations) (1a-05, 1a-10, 1a-15, 1a-20), an MME (1a-25, Mobility Management Entity) and an S-GW (1a-30, Serving-Gateway). A user equipment (UE or terminal) (1a-35) accesses an external network through the ENBs (1a-05 to 1a-20) and the S-GW (1a-30).

[0044] In Fig. 1a, ENBs (1a-05 to 1a-20) correspond to the existing Node B of the UMTS system. ENBs are connected to UEs (1a-35) via a wireless channel and perform a more complex role than the existing Node B. In the LTE system, all user traffic, including real-time services such as VoIP (Voice over IP) via the Internet Protocol, is serviced through a shared channel. Therefore, a device that collects status information such as the buffer status of UEs, available transmission power status, and channel status and performs scheduling is required, and this is handled by the ENBs (1a-05 to 1a-20). One ENB typically controls multiple cells. For example, in order to implement a transmission rate of 100 Mbps, the LTE system uses, for example, orthogonal frequency division multiplexing (OFDM) as a wireless access technology in a 20 MHz bandwidth. In addition, it applies Adaptive Modulation & Coding (AMC) method that determines modulation scheme and channel coding rate according to the channel condition of the terminal. S-GW (1a-30) is a device that provides data bearers and creates or removes data bearers according to the control of MME (1a-25). MME is a device that is responsible for mobility management function for terminals as well as various control functions and is connected to multiple base stations.

[0045] FIG. 1b is a diagram illustrating a wireless protocol structure in an LTE system according to one embodiment.

[0046] Referring to Figure 1b, the wireless protocol of the LTE system consists of PDCP (Packet Data Convergence Protocol 1b-05, 1b-40), RLC (Radio Link Control 1b-10, 1b-35), and MAC (Medium Access Control 1b-15, 1b-30) in the terminal and ENB, respectively. PDCP (Packet Data Convergence Protocol) (1b-05, 1b-40) is responsible for operations such as IP header compression / decompression. The main functions of PDCP are summarized as follows.

[0047] - Header compression and decompression (ROHC only)

[0048] - User data transfer function

[0049] - In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM

[0050] - Order reordering function (For split bearers in DC (only support for RLC AM): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

[0051] - Duplicate detection function (Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM)

[0052] - Retransmission function (Retransmission of PDCP SDUs at handover and, for split bearers in DC, of ​​PDCP PDUs at PDCP data-recovery procedure, for RLC AM)

[0053] - Encryption and decryption functions (Ciphering and deciphering)

[0054] - Timer-based SDU discard in uplink.

[0055] Radio Link Control (RLC) (1b-10, 1b-35) reconfigures PDCP PDUs (Packet Data Units) to an appropriate size and performs ARQ operations, etc. The main functions of RLC are summarized as follows.

[0056] - Data transfer function (Transfer of upper layer PDUs)

[0057] - ARQ function (Error Correction through ARQ (only for AM data transfer))

[0058] - Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer)

[0059] - Re-segmentation of RLC data PDUs (only for AM data transfer)

[0060] - Reordering of RLC data PDUs (only for UM and AM data transfer)

[0061] - Duplicate detection (only for UM and AM data transfer)

[0062] - Error detection function (Protocol error detection (only for AM data transfer))

[0063] - RLC SDU discard function (RLC SDU discard (only for UM and AM data transfer))

[0064] - RLC re-establishment function

[0065] MAC (1b-15, 1b-30) connects to multiple RLC layer devices configured in a single terminal, and multiplexes RLC PDUs into MAC PDUs and demultiplexes RLC PDUs from MAC PDUs. The main functions of MAC are summarized as follows.

[0066] - Mapping function (Mapping between logical channels and transport channels)

[0067] - Multiplexing and demultiplexing function (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)

[0068] - Scheduling information reporting function

[0069] - HARQ function (Error correction through HARQ)

[0070] - Priority handling between logical channels of one UE

[0071] - Priority handling between UEs by means of dynamic scheduling

[0072] - MBMS service identification function

[0073] - Transport format selection function

[0074] - Padding function

[0075] The physical layer (1b-20, 1b-25) performs the operation of channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it over a wireless channel, or demodulating and channel decoding OFDM symbols received over a wireless channel and transmitting them to the upper layer.

[0076] FIG. 1c is a diagram illustrating the structure of a next-generation wireless communication system according to one embodiment.

[0077] Referring to FIG. 1c, as illustrated, a wireless access network of a next-generation wireless communication system (hereinafter referred to as NR or 2g) is composed of a next-generation base station (New Radio Node B, hereinafter referred to as NR gNB or NR base station) (1c-10) and an NR CN (1c-05, New Radio Core Network). A user terminal (New Radio User Equipment, hereinafter referred to as NR UE or terminal) (1c-15) accesses an external network through the NR gNB (1c-10) and the NR CN (1c-05).

[0078] In Fig. 1c, the NR gNB (1c-10) corresponds to the eNB (Evolved Node B) of the existing LTE system. The NR gNB is connected to the NR UE (1c-15) via a wireless channel and can provide a service that is superior to the existing Node B. In the next-generation wireless communication system, all user traffic is serviced through a shared channel, so a device that collects status information such as the buffer status of UEs, available transmission power status, and channel status and performs scheduling is required, and the NR gNB (1c-10) is in charge of this. One NR gNB typically controls multiple cells. In order to implement ultra-high-speed data transmission compared to the current LTE, it can have a bandwidth exceeding the existing maximum, and beamforming technology can be additionally grafted using Orthogonal Frequency Division Multiplexing (OFDM) as a wireless access technology. In addition, it applies the Adaptive Modulation & Coding (AMC) method that determines the modulation scheme and channel coding rate according to the channel condition of the terminal. NR CN (1c-05) performs functions such as mobility support, bearer setup, and QoS setup. NR CN is a device that handles various control functions as well as mobility management functions for terminals and is connected to multiple base stations. In addition, the next-generation wireless communication system can also be linked with the existing LTE system, and NR CN is connected to MME (1c-25) through a network interface. MME is connected to the existing base station, eNB (1c-30).

[0079] FIG. 1d is a diagram illustrating a wireless protocol structure of a next-generation wireless communication system according to one embodiment.

[0080] Referring to FIG. 1d, the wireless protocol of the next-generation wireless communication system is composed of NR SDAP (1d-01, 1d-45), NR PDCP (1d-05, 1d-40), NR RLC (1d-10, 1d-35), and NR MAC (1d-15, 1d-30) in the terminal and NR base station, respectively.

[0081] Key features of NR SDAP (1d-01, 1d-45) may include some of the following:

[0082] - Transfer of user plane data

[0083] - Mapping function between QoS flow and data bearer for both DL and UL

[0084] - QoS flow ID marking function for uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0085] - Ability to map relective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0086] For the above SDAP layer device, the terminal can be configured by RRC message for each PDCP layer device, each bearer, or each logical channel, whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device, and when the SDAP header is configured, the terminal can be instructed to update or reset the mapping information for the QoS flow and data bearer of the uplink and downlink with the NAS QoS reflection configuration 1-bit indicator (NAS reflective QoS) and the AS QoS reflection configuration 1-bit indicator (AS reflective QoS) of the SDAP header. The SDAP header can include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support a smooth service.

[0087] The main functions of NR PDCP (1d-05, 1d-40) may include some of the following functions:

[0088] - Header compression and decompression (ROHC only)

[0089] - User data transfer function

[0090] - In-sequence delivery of upper layer PDUs

[0091] - Out-of-sequence delivery of upper layer PDUs

[0092] - PDCP PDU reordering for reception

[0093] - Duplicate detection of lower layer SDUs

[0094] - Retransmission function (Retransmission of PDCP SDUs)

[0095] - Encryption and decryption functions (Ciphering and deciphering)

[0096] - Timer-based SDU discard in uplink.

[0097] The reordering function of the NR PDCP device above refers to a function of reordering PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order, or may include a function of transmitting data directly without considering the order, may include a function of recording lost PDCP PDUs by reordering the order, may include a function of reporting the status of lost PDCP PDUs to the transmitting side, and may include a function of requesting retransmission of lost PDCP PDUs.

[0098] The main features of NR RLC(1d-10, 1d-35) may include some of the following:

[0099] - Data transfer function (Transfer of upper layer PDUs)

[0100] - In-sequence delivery of upper layer PDUs

[0101] - Out-of-sequence delivery of upper layer PDUs

[0102] - ARQ function (Error Correction through ARQ)

[0103] - Concatenation, segmentation and reassembly of RLC SDUs

[0104] - Re-segmentation of RLC data PDUs

[0105] - Reordering of RLC data PDUs

[0106] - Duplicate detection function

[0107] - Protocol error detection

[0108] - RLC SDU discard function

[0109] - RLC re-establishment function

[0110] The in-sequence delivery function of the NR RLC device above refers to the function of sequentially transmitting RLC SDUs received from a lower layer to an upper layer, and may include a function of reassembling and transmitting RLC SDUs when an RLC SDU is originally received divided into multiple RLC SDUs, may include a function of reordering received RLC PDUs based on RLC SN (sequence number) or PDCP SN (sequence number), may include a function of recording lost RLC PDUs by reordering the sequence, may include a function of reporting the status of lost RLC PDUs to the transmitting side, may include a function of requesting retransmission of lost RLC PDUs, may include a function of sequentially transmitting only RLC SDUs up to the lost RLC SDU to an upper layer when there is a lost RLC SDU, or may include a function of sequentially transmitting all RLC SDUs received before the timer starts when a predetermined timer expires even when there is a lost RLC SDU. Or, even if there are lost RLC SDUs, if a predetermined timer has expired, it may include a function to sequentially deliver all RLC SDUs received up to the upper layer. In addition, the RLC PDUs may be processed in the order they are received (in the order of arrival, regardless of the order of the sequence number) and delivered to the PDCP device out of sequence (out-of-sequence delivery). In the case of segments, the segments stored in the buffer or to be received later may be received, reconstructed into a single complete RLC PDU, processed, and then delivered to the PDCP device.The above NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

[0111] The out-of-sequence delivery function of the NR RLC device above refers to the function of directly delivering RLC SDUs received from a lower layer to an upper layer regardless of the order, and may include a function of reassembling and delivering RLC SDUs when an original RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing the RLC SN or PDCP SN of received RLC PDUs and arranging the order to record lost RLC PDUs.

[0112] NR MAC (1d-15, 1d-30) can be connected to multiple NR RLC layer devices configured in one terminal, and the main functions of NR MAC can include some of the following functions.

[0113] - Mapping function (Mapping between logical channels and transport channels)

[0114] - Multiplexing / demultiplexing of MAC SDUs

[0115] - Scheduling information reporting function

[0116] - HARQ function (Error correction through HARQ)

[0117] - Priority handling between logical channels of one UE

[0118] - Priority handling between UEs by means of dynamic scheduling

[0119] - MBMS service identification function

[0120] - Transport format selection function

[0121] - Padding function

[0122] The NR PHY layer (1d-20, 1d-25) can perform operations such as channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it through a wireless channel, or demodulating and channel decoding OFDM symbols received through a wireless channel and transmitting them to a higher layer.

[0123] FIG. 1e is a diagram for explaining a method for a terminal in an RRC idle mode (RRC_IDLE) or an RRC inactive state (RRC_INACTIVE) to perform a cell reselection evaluation procedure in a next-generation wireless communication system according to one embodiment.

[0124] The cell reselection evaluation procedure may refer to a procedure for determining whether to maintain the current serving cell or reselect a cell to a neighbor cell when the service quality of the serving cell on which the terminal is currently camped becomes lower than the service quality of the neighbor cell due to a predetermined reason or movement, while in the RRC idle mode (RRC_IDLE) or RRC inactive state (RRC_INACTIVE).

[0125] In the case of handover, whether or not to perform a handover is determined by the network (AMF or source gNB), whereas in the case of cell reselection, a terminal in RRC idle mode or RRC inactive state can determine whether or not to perform a cell reselection on its own based on cell measurement values. The cell to be reselected by the terminal may refer to a cell using the same NR frequency (NR intra-frequency or serving NR frequency) as the serving cell on which it is currently camping, a cell using a different NR frequency (NR inter-frequency) from the serving cell, or a cell on a frequency (inter-RAT frequency) using a different radio access technology (RAT).

[0126] Referring to FIG. 1e, the terminal (1e-01) may be in RRC connected mode (RRC_CONNECTED) by establishing an RRC connection with an NR cell (1e-02) (1e-03).

[0127] The NR cell (1e-02) may transmit (1e-04) an RRC connection release message (RRCRelease) to release the RRC connection with the terminal (1e-01) in the RRC connected mode. If the message includes suspension configuration information (suspendConfig), the terminal may transition (1e-05) to an RRC inactive mode (RRC_INACTIVE). If the message does not include suspendConfig, the terminal may transition (1e-05) to an RRC idle mode (RRC_IDLE). The message may include cellReselectionPriorities for the terminal to perform cell reselection. cellReselectionPriorities may store at least one value among freqPriorityListEUTRA, freqPriorityListNR, and t320. If the t320 value is included, the terminal may drive the T320 timer with the corresponding value. Specifically, the setting information included in the RRCRelease message may be as shown in Table 0 below.

[0128] [Table 0]

[0129]

[0130]

[0131]

[0132] In step 1e-13, a terminal (1e-01) in RRC idle mode or RRC deactivation can obtain essential system information from an NR cell (1e-02). In the present disclosure, the Master Information Block (MIB) and System Information Block 1 (SIB1) may be referred to as essential system information.

[0133] In step 1e-15, a terminal (1e-01) in RRC idle mode or RRC inactive state can perform a cell selection procedure based on the essential system information acquired in step 1e-13. That is, the terminal can find an NR suitable cell belonging to the selected PLMN or SNPN and camp on the cell. The cell on which the terminal camps on can be referred to as a serving cell. In the present disclosure, a suitable cell can be defined if the conditions in Table 1 below are satisfied based on the 3GPP standard document "38.304: User Equipment (UE) procedures in Idle mode and RRC Inactive state."

[0134] [Table 1]

[0135]

[0136] For reference, the above terminal can be judged to fulfill the cell selection criteria if the following mathematical expression 1 is satisfied.

[0137] [Mathematical Formula 1]

[0138]

[0139] The definitions of the parameters included in mathematical expression 1 are as follows.

[0140]

[0141] At step 1e-20, a terminal (1e-01) in RRC idle mode or RRC deactivated state can acquire system information (e.g., SIB2, SIB3, SIB4, SIB5) containing cell reselection information from a serving cell (1e-02) to perform a cell reselection evaluation procedure. SIB2 may include information / parameters commonly applied to reselecting NR intra-frequency, NR inter-frequency, and inter-RAT frequency cells by a terminal in RRC idle mode or RRC deactivated state, and NR intra-frequency cell reselection information excluding information related to NR intra-frequency neighboring cells. For example, SIB2 may include one cell reselection priority setting information for a serving NR frequency (the frequency to which the currently camped-on cell belongs). The cell reselection priority setting information may mean cellReselectionPriority and cellReselectionSubPriority. Specifically, cellReselectionPriority can accept an integer value (for example, an integer value from 0 to 7), and cellReselectionSubPriority can accept a decimal value (for example, a decimal value from 0.2, 0.4, 0.6, 0.8). If both cellReselectionPriority and cellReselectionSubPriority are signaled, the terminal can derive a cell reselection priority value by adding the two values. Note that a larger cell reselection priority value indicates a higher priority. Specifically, the cell reselection configuration information broadcasted in SIB2 can be as shown in Table 2 below.

[0142] [Table 2]

[0143]

[0144]

[0145]

[0146] SIB3 may include neighboring cell information / parameters for a UE in RRC idle mode or RRC inactive state to reselect an NR intra-frequency cell. For example, SIB3 may broadcast an NR intra-frequency cell list (intraFreqNeighCellList) for reselecting an NR intra-frequency cell, a cell list for which NR intra-frequency cell reselection is allowed (intraFreqAllowedCellList), and a cell list for which NR intra-frequency cell reselection is not allowed (intraFreqExcludedCellList). Specifically, SIB3 may broadcast the information in Table 3 below.

[0147] [Table 3]

[0148]

[0149]

[0150] SIB4 may include information / parameters for a UE in RRC idle mode or RRC inactive state to reselect an NR inter-frequency cell. For example, SIB4 may broadcast one or more NR inter-frequencies, and may broadcast one cell reselection priority setting information for each NR inter-frequency. The cell reselection priority setting information for each NR inter-frequency means the above-described contents (e.g., cellReselectionPriority and / or cellReselectionSubPriority mapped to each NR inter-frequency), but has the characteristic that one cell reselection priority setting information for each inter-frequency is optionally broadcast. Specifically, SIB4 may broadcast the information in Table 4 below.

[0151] [Table 4]

[0152]

[0153]

[0154]

[0155] SIB5 may include information / parameters for a UE in RRC idle mode or RRC inactive state to reselect an inter-RAT frequency cell. For example, SIB5 may broadcast one or more EUTRA frequencies, and may broadcast one piece of cell reselection priority setting information for each EUTRA frequency. The cell reselection priority setting information for each EUTRA frequency refers to the above-described content (e.g., cellReselectionPriority and / or cellReselectionSubPriority mapped to each EUTRA frequency), but has the characteristic that one piece of cell reselection priority setting information for each EUTRA frequency is optionally broadcast. Specifically, SIB5 may broadcast the information in Table 5 below.

[0156] [Table 5]

[0157]

[0158]

[0159] A terminal in RRC idle mode or RRC deactivation can perform a cell reselection evaluation process. The cell reselection evaluation process can refer to a series of three processes: determining reselection priorities, performing frequency measurements by applying measurement rules for cell reselection, and evaluating cell reselection criteria to reselect a cell.

[0160] At step 1e-25, a terminal in RRC idle mode or RRC disabled state can determine a reselection priority based on an RRC release message received at step 1e-04 or system information received at step 1e-20. If the RRC release message received at step 1e-04 includes cellReselectionPriorities and cellReselectionPriorities does not have a t320 timer value or the t320 timer value is set and the T320 timer is running, the terminal can determine a reselection priority based on the RRC release message. That is, if celllReselectionPriorities included in the RRC release message can be applied, the terminal can determine a reselection priority based on the RRC release message. If the RRC release message does not include cellReselectionPriorities or cellReselectionPriorities is released, the terminal can determine a reselection priority based on the system information received at step 1e-20. The terminal according to the present disclosure can determine, based on the cell reselection priority value mapped to the NR frequency to which the serving cell currently camped-on belongs, whether the cell reselection priority for each NR inter-frequency or inter-RAT frequency has the same cell reselection priority as the NR frequency to which the serving cell belongs, has a cell reselection priority higher than the NR frequency to which the serving cell belongs, or has a cell reselection priority lower than the NR frequency to which the serving cell belongs.For example, if the cell reselection priority value mapped to the NR frequency to which the serving cell currently camped on belongs in the system information acquired at step 1e-20 is 3, the cell reselection priority value of inter NR frequency 1 is 2, the cell reselection priority value of inter NR frequency 2 is 3, the cell reselection priority value of inter NR frequency 3 is 4, and the cell reselection priority value of EUTRA frequency 1 is 2, the terminal may determine inter NR frequency 1 and EUTRA frequency 1 to have lower reselection priorities, determine the cell reselection priorities of inter NR frequency 2 to be equal (equal reselection priority), and determine the cell reselection priority of inter NR frequency 3 to have higher reselection priorities.

[0161] At step 1e-30, a terminal in RRC idle mode or RRC disabled state can perform frequency measurements for cell reselection. At this time, the terminal can perform frequency measurements using the following measurement rules according to the cell reselection priority determined at step 1e-25 to minimize battery consumption.

[0162] - The terminal may not perform NR intra-frequency measurement if the following condition 1 is satisfied. Otherwise (for example, if the following condition 1 is not satisfied), the terminal performs NR intra-frequency measurement.

[0163] ■ Condition 1: The reception level (Srxlev) of the serving cell is greater than the SIntraSearchP threshold and the reception quality (Squal) of the serving cell is greater than the SIntraSearchQ threshold (Serving cell fulfils Srxlev > SIntraSearchP and Squal > SIntraSearchQ).

[0164] - The terminal can perform measurements according to the 3GPP TS 38.133 standard for NR inter-frequency or inter-RAT frequency that has a higher reselection priority than the NR frequency of the current serving cell.

[0165] - For an NR inter-frequency having a reselection priority lower than or equal to the NR frequency of the current serving cell and an inter-RAT frequency having a reselection priority lower than the NR frequency of the current serving cell, the terminal may not perform measurement if Condition 2 below is satisfied. Otherwise (for example, if Condition 2 below is not satisfied), the terminal measures cells in an NR inter-frequency having a reselection priority lower than or equal to the NR frequency or measures cells in an inter-RAT frequency having a reselection priority lower than the NR frequency.

[0166] ■ Condition 2: The reception level (Srxlev) of the serving cell is greater than the SnonIntraSearchP threshold and the reception quality (Squal) of the serving cell is greater than the SnonIntraSearchQ threshold (Serving cell fulfils Srxlev > SnonIntraSearchP and Squal > SnonIntraSearchQ).

[0167] For reference, the aforementioned thresholds (SintraSearchP, SintraSearchQ, SnonIntraSearchP SnonintraSearchQ) can be broadcast in the system information acquired at step 1e-20.

[0168] In step 1e-35, a UE in RRC idle mode or RRC disabled state may decide to reselect a cell satisfying cell reselection criteria based on the measurement value performed in step 1e-30. Different criteria may be applied to the cell reselection criteria depending on the cell reselection priority. If multiple cells satisfying the cell reselection criteria have different cell reselection priorities, reselecting a frequency / RAT cell with a higher cell reselection priority takes precedence over reselecting a frequency / RAT cell with a lower priority. Specifically, the UE's behavior with respect to the reselection criteria of an inter-frequency / inter-RAT cell with a higher priority than that of the current serving cell is as follows.

[0169] - First movement:

[0170] ■ If SIB2 is broadcast with a threshold for threshServingLowQ and 1 second has passed since the terminal camped on the current serving cell, and the signal quality (Squal) of the inter-frequency / inter-RAT cell is greater than the threshold ThreshX,HighQ during a specific time interval TreselectionRAT (Squal > ThreshX,HighQ during a time interval TreselectionRAT), the terminal performs reselection to the inter-frequency / inter-RAT cell.

[0171] - Second movement:

[0172] ■ If the above terminal cannot perform the first operation, it performs the second operation.

[0173] ■ If 1 second has passed since the terminal camped on the current serving cell and the reception level (Srxlev) of the inter-frequency / inter-RAT cell is greater than the threshold ThreshX,HighP during a specific time interval TreselectionRAT (Srxlev > ThreshX,HighP during a time interval Treselection-RAT-), the terminal performs reselection to the inter-frequency / inter-RAT cell.

[0174] Here, the terminal determines the signal quality (Squal), reception level (Srxlev), and threshold values ​​(ThreshX) of the inter-frequency cell. , HighQ, ThreshX, HighP), TreselectionRAT The values ​​perform the first or second operation based on the information included in SIB4 broadcast from the serving cell, and the signal quality (Squal), reception level (Srxlev), and threshold (ThreshX,HighQ) of the inter-RAT cell. , ThreshX,High P ), TreselectionRAT The values ​​perform the first or second action based on the information contained in SIB5 broadcast from the serving cell. For example, in SIB4, value or It includes values, etc., and derives the signal quality (Squal) or reception level (Srxlev) of the inter-frequency cell based on this. If there are multiple cells in the NR frequency that satisfy the high cell reselection priority, the terminal can reselect the highest-ranked cell among the cells that satisfy the intra-frequency / inter-frequency cell reselection criteria that have the same priority as the frequency of the current serving cell described below.

[0175] Additionally, the terminal's operation for the reselection criteria of intra-frequency / inter-frequency cells that have the same priority as the frequency of the current serving cell is as follows.

[0176] - Third movement:

[0177] ■ If the signal quality (Squal) and reception level (Srxlev) of an intra-frequency / inter-frequency cell are greater than 0, the cell-specific rank is derived based on the measured value (RSRP) (The UE shall perform ranking of all cells that fulfill the cell selection criterion S). The ranks of the serving cell and neighboring cells are each calculated using the following mathematical expression 2.

[0178] [Equation 2]

[0179]

[0180] ● Here, Qmeas,s is the RSRP measurement value of the serving cell, Qmeas,n is the RSRP measurement value of the neighboring cells, Qhyst is the hysteresis value of the serving cell, and Qoffset is the offset between the serving cell and the neighboring cells. The Qhyst value is included in SIB2, and the value is commonly used for intra-frequency / inter-frequency cell reselection. In case of intra-frequency cell reselection, Qoffset is signaled per cell, applied only to the indicated cell, and included in SIB3. In case of inter-frequency cell reselection, Qoffset is signaled per cell, applied only to the indicated cell, and included in SIB4. If the Rank of the neighboring cell obtained from the above mathematical expression 2 is greater than the Rank of the serving cell (Rn > Rs), the optimal cell among the neighboring cells is reselected.

[0181] ● Here can mean connEstFailOffset included in ConnEstFailureControld broadcasted in SIB1 as an offset temporarily applied to the cell, and can be applied when RRC connection fails (e.g., when T300 timer expires).

[0182] Additionally, the terminal's behavior with respect to the reselection criteria of an inter-frequency / inter-RAT cell with a lower priority than the frequency of the current serving cell is as follows.

[0183] - 4th movement:

[0184] ■ If SIB2 is broadcast with a threshold for threshServingLowQ and 1 second has passed since the terminal camped on the current serving cell, if the signal quality (Sqaul) of the current serving cell is lower than the threshold ThreshServing,LowQ (Squal < ThreshServing,LowQ) and the signal quality (Squal) of the inter-frequency / inter-RAT cell is higher than the threshold ThreshX,LowQ- during a specific time TreselectionRAT (Squal > ThreshX,LowQ during a time interval TreselectionRAT), the terminal performs reselection to the inter-frequency / inter-RAT cell.

[0185] - Movement 5:

[0186] ■ If the above terminal cannot perform the 4th operation, it performs the 5th operation.

[0187] ■ If 1 second has passed since the terminal camped on the current serving cell, and the reception level (Srxlev) of the current serving cell is less than the threshold ThreshServing,LowP (Srxlev < ThreshServing,LowP) and the reception level (Srxlev) of the inter-frequency / inter-RAT cell is greater than the threshold ThreshX,LowP- during a specific time interval TreselectionRAT (Srxlev > ThreshX,LowP during a time interval TreselectionRAT), the terminal performs reselection to the inter-frequency / inter-RAT cell.

[0188] Here, the fourth or fifth operation for the inter-frequency cell of the terminal is the thresholds (ThreshServing,LowQ, ThreshServing,LowP) included in SIB2 broadcasted in the serving cell and the signal quality (Squal), reception level (Srxlev), and thresholds (ThrehX,LowQ, ThreshServing,LowP) of the inter-frequency cell included in SIB4 broadcasted in the serving cell. ThreshX, LowP), TreselectionRAT, and the fourth or fifth operation for the inter-RAT cell of the terminal is performed based on the thresholds (ThreshServing, LowQ, ThreshServing, LowP) included in SIB2 broadcasted from the serving cell and the signal quality (Squal), reception level (Srxlev), thresholds (ThreshX, LowQ, ThreshX, LowP), TreselectionRAT of the inter-RAT cell included in SIB5 broadcasted from the serving cell. For example, in SIB4 value or It includes values, etc., and derives the signal quality (Squal) or reception level (Srxlev) of the inter-frequency cell based on this. If there are multiple cells in the NR frequency that satisfy the high cell reselection priority, the terminal can reselect the highest ranked cell among the cells that satisfy the reselection criteria of the intra-frequency / inter-frequency cell that has the same priority as the frequency of the current serving cell described below.

[0189] At step 1e-40, a terminal in RRC idle mode or RRC inactive state receives system information (e.g., MIB or SIB1) broadcast from a candidate target cell before finally reselecting a candidate target cell, and determines based on the received system information whether the reception level (Srxlev) and reception quality (Squal) of the candidate target cell satisfy a cell selection criterion called S-criterion (Mathematical Formula 1) (Srxlev > 0 AND Squal > 0). If Mathematical Formula 1 is satisfied and the candidate target cell is suitable, the terminal can reselect the candidate target cell.

[0190] FIG. 1f is a diagram for explaining a method for a terminal supporting a low-power wake-up receiver to perform cell reselection in a next-generation wireless communication system according to an embodiment.

[0191] A terminal (1f-01) according to an embodiment of the present disclosure may be equipped with a Main Radio (MR) and a Low Power Wake-Up Receiver (LR) to perform a predetermined operation. The MR (1f-02) equipped in the terminal may refer to a transceiver module (Tx / Rx module operating for NR signals / channels apart from signals / channels related to low-power wake-up) from a base station via the MR. For example, the terminal may receive a wake-up signal (WUS) transmitted by a base station via the MR, and based on this, the terminal may determine whether to additionally receive a paging message. Alternatively, the terminal may receive a Synchronization Signal / PBCH block (SSB) transmitted by a base station via the MR, and based on this, the terminal may select or reselect a cell. For reference, a terminal according to the embodiment of the aforementioned FIG. 1e refers to a terminal equipped with only an MR. An LR (1f-03) additionally equipped in the terminal may refer to a receiver module (Rx module operating for receiving / processing signals / channels related to low-power wake-up). For example, the terminal may receive a low power wake-up signal (LP-WUS) transmitted by a base station through the LR, and based on this, the terminal may determine whether to turn on or off the MR, and thus determine whether to receive a WUS transmitted by the base station or a paging message.Alternatively, the terminal can receive a low power synchronization signal (LP-SS) transmitted by the base station via LR, and based on this, determine whether to measure surrounding cells or whether LP-WUS reception is possible. Since LP-WUS / LP-SS uses a smaller channel bandwidth and lower complex channel coding than WUS / SSB, the power consumed when using LR is less than that of MR, and thus the terminal can obtain a power saving effect by turning off MR and using LR according to certain conditions. In order to save power, the terminal can determine whether to turn on or off MR based on a signal related to low power wake-up received via LR. For reference, a state in which the MR of the terminal is turned off can be referred to as an ultra-deep-sleep state.

[0192] Referring to FIG. 1f, the terminal (1f-01) may be in RRC connected mode (RRC_CONNECTED) by establishing an RRC connection with an NR cell (1f-05) (1f-06).

[0193] In step 1f-07, the terminal (1f-01) may transmit a terminal capability information message (UECapabilityInformation) at the request of the base station (1f-05). The message may include at least one of an indicator indicating whether LR is supported and / or an indicator indicating that a modified cell reselection procedure (or cell reselection evaluation procedure) may be performed according to LR support.

[0194] In step 1f-08, the NR base station (1f-05) may transmit an RRC connection release message (RRCRelease) to the terminal (1f-01). The message may include an indicator instructing the terminal to determine the frequency to which the cell belongs as the highest cell reselection priority when selecting or reselecting a cell supporting LP-WUS and / or LP-SS.

[0195] In step 1f-10, the terminal (1f-01) may transition to RRC idle mode (RRC_IDLE) or RRC inactive mode (RRC_INACTIVE). This may follow step 1e-05 of the aforementioned embodiment 1e.

[0196] In step 1f-15, the terminal (1f-01) can receive essential system information broadcast by the NR cell (1f-05) via MR (1f-02). In the present disclosure, the Master Information Block (MIB) and System Information Block 1 (SIB1) may be referred to as essential system information. The essential system information (MIB or SIB1) may include certain information applicable / available to a terminal supporting LR. The certain information may include at least one of the following.

[0197] - Indicator of whether to transmit Low-Power Synchronization Signal (LP-SS) or setting information for LP-SS

[0198] - Indicator of whether to transmit Low-Power Wake-up Signal (LP-WUS) or configuration information for LP-WUS

[0199] ■ The above indicators may correspond to indicators indicating that the serving frequency supports LP-WUS and / or LP-SS.

[0200] - : Minimum signal reception level value required when a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS.

[0201] - : Minimum signal quality level value required when a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS.

[0202] - : Minimum signal reception level offset value required when a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS.

[0203] - : Minimum signal quality level offset value required when a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS.

[0204] In step 1f-20, the terminal (1f-01) may perform a cell selection procedure based on the essential system information received in step 1f-15. The terminal may search for an NR suitable cell belonging to the selected PLMN or SNPN and camp on the cell. The definition of a suitable cell may follow the definition mentioned in the aforementioned embodiment 1e. Since a terminal (1f-01) supporting LR can efficiently save power by selecting or reselecting a cell (1f-05) supporting LP-WUS and / or LP-SS, a terminal (1f-01) according to the present disclosure can derive a cell selection reception signal level value (Srxlev) and a cell selection signal quality value (Squal) through at least one of the methods proposed below (i.e., the methods may be combined or only one of the methods may be performed), and if both Srxlev and Squal are greater than 0, it can be determined that a cell selection criterion is fulfilled.

[0205] - Method 1: When a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS, Srxlev and Squal are derived by applying the minimum signal reception level value and minimum quality level value required.

[0206]

[0207] For reference, and The remaining parts, except for applying the above-described embodiment 1e, may follow. At this time, , , , At least one of them may not be applicable to the terminal, in which case the terminal may consider the value as 0 (i.e., the parameter may not be considered in Srxlev and Squal).

[0208] - Method 2: When selecting a cell supporting LP-WUS and / or LP-SS that can be applied by a terminal supporting LR, Srxlev and Squal are derived by applying the minimum signal reception level offset value and the minimum quality level offset value required.

[0209] (Option 1)

[0210]

[0211] (Option 2)

[0212]

[0213] For reference, and The remaining parts, except for the additional application, may follow the aforementioned embodiment 1e.

[0214] The difference between the two proposed options is that they relatively control the extent to which the terminal preferentially selects cells supporting LP-WUS and / or LP-SS (i.e., Option 1 may cause the terminal to select fewer cells supporting LP-WUS and / or LP-SS, while Option 2 may cause the terminal to select more cells supporting LP-WUS and / or LP-SS). Of course, and Depending on how the range of values ​​that can be signaled is defined, Option 1 and Option 2 may be expressed as one. , , , , , At least one of them may not be applicable to the terminal, in which case the terminal may consider the value as 0 (i.e., the parameter may not be considered in Srxlev and Squal).

[0215] - Method 3: When a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS, the minimum signal reception level value and its offset value are applied, and the minimum quality level value and its offset value are applied to derive Srxlev and Squal.

[0216]

[0217] For reference, and Applying Option 2 proposed in Method 2 may also be applied to the above Method 3.

[0218] The terminal can select a cell by deriving Srxlev and Squal through MR (i.e., a signal / message transmitted by the base station through MR) or through LR (i.e., LP-SS or LP-WUS transmitted by the base station through LR). Alternatively, the terminal can determine whether the cell selection criteria are met based on the aforementioned embodiment 1e through MR, and then additionally determine whether the cell selection criteria are met through the method proposed in the present disclosure through LR to select a cell.

[0219] In step 1f-25, the terminal (1f-01) may acquire system information (e.g., SIB2, SIB3, SIB4, SIB5, or a new SIB) containing cell reselection information from the serving cell (1f-05) to perform a cell reselection evaluation procedure. This may follow the aforementioned embodiment 1e. In the present disclosure, the system information may include predetermined information applicable / available to a terminal supporting LR. The predetermined information may include at least one of the following. The predetermined information may also be referred to as cell reselection-related configuration information of a terminal supporting LR.

[0220] - Indicator indicating that the serving frequency supports LP-WUS and / or LP-SS.

[0221] - : Minimum signal reception level value required when a terminal supporting LR reselects a cell supporting LP-WUS and / or LP-SS.

[0222] ■ The above values ​​can be signaled by frequency.

[0223] - : Minimum signal quality level value required when a terminal supporting LR reselects a cell supporting LP-WUS and / or LP-SS.

[0224] ■ The above values ​​can be signaled by frequency.

[0225] - : Minimum signal reception level offset value required when a terminal supporting LR reselects a cell supporting LP-WUS and / or LP-SS.

[0226] ■ The above value can be signaled for each cell within each frequency, and at this time, a physical cell identifier (Physical Cell Id, PhyCellId) representing the cell can be signaled.

[0227] - : Minimum signal quality level offset value required when a terminal supporting LR reselects a cell supporting LP-WUS and / or LP-SS.

[0228] ■ The above value can be signaled for each cell within each frequency, and at this time, a physical cell identifier (Physical Cell Id, PhyCellId) representing the cell can be signaled.

[0229] - List of cells allowed for terminals supporting LP-WUS and / or LP-SS by frequency

[0230] ■ The above terminal can consider only the cells included in the above list as candidate cells for cell reselection.

[0231] - List of cells that must be excluded by terminals supporting LP-WUS and / or LP-SS by frequency

[0232] ■ The above terminal may not consider the cells included in the above list as candidate cells for cell reselection.

[0233] - QoffsetLR value for each neighboring cell supporting LP-WUS and / or LP-SS in the frequency to which the serving cell belongs (intra-frequency)

[0234] ■ The above QoffsetLR value is an offset between the serving cell and the surrounding cells within the frequency to which the serving cell belongs. The above value is used when deriving Rank (Mathematical Formula 2) in the above-described embodiment, and can be applied in at least one of the following ways.

[0235] ◆ Method 1: Rn = Qmeas,n - Qoffset - QoffsetLR- Qoffsettemp

[0236] ◆ Method 2: Rn = Qmeas,n - QoffsetLR- Qoffsettemp

[0237] - QoffsetLR value for each neighboring cell supporting LP-WUS and / or LP-SS on different frequencies (inter-frequency) from the serving cell

[0238] ■ The above QoffsetLR value is an offset between the serving cell and a neighboring cell within a different frequency range. The above value is used when deriving Rank (Mathematical Formula 2) in the above-described embodiment, and can be applied in at least one of the following ways.

[0239] ◆ Method 1: Rn = Qmeas,n - Qoffset - QoffsetLR- Qoffsettemp where Qoffset = + , if is valid, otherwise this equals to

[0240] ◆ Method 2: Rn = Qmeas,n - - QoffsetLR- Qoffsettemp

[0241] ◆ Method 3: Rn = Qmeas,n - QoffsetLR- Qoffsettemp

[0242] The above terminal (1f-01) can perform a cell reselection evaluation process. The cell reselection evaluation process may refer to a series of processes for performing frequency measurements by applying reselection priorities handling and measurement rules for cell reselection, and evaluating cell reselection criteria to reselect a cell.

[0243] In step 1f-30, the terminal (1f-01) according to the present disclosure can determine the cell reselection priority through at least one of the methods proposed below (i.e., the methods may be combined or only one method may be performed).

[0244] - Method 1: When camping on / selecting or reselecting a cell supporting LP-WUS and / or LP-SS, the terminal may determine the serving frequency with the highest cell reselection priority.

[0245] - Method 2: If an indicator that the serving frequency supports LP-WUS and / or LP-SS is broadcast in the received system information (1f-15, 1f-25), the terminal can determine the serving frequency as the highest cell reselection priority.

[0246] - Method 3: If the received RRC connection release message (1f-08) includes an instruction to determine the frequency to which the cell belongs as the highest cell reselection priority when selecting or reselecting a cell supporting LP-WUS and / or LP-SS, the terminal may determine the serving frequency as the highest cell reselection priority.

[0247] In step 1f-35, the terminal (1f-01) may perform frequency measurement for cell reselection. This may follow the aforementioned embodiment 1e.

[0248] In step 1f-40, the terminal (1f-01) may decide to reselect a cell that satisfies the cell reselection criteria based on the measurement value performed in step 1f-35. This may follow the aforementioned embodiment 1e. The terminal (1f-01) according to the present disclosure may derive the signal reception level value (Srxlev) and the signal quality value (Squal) of the neighboring cell by applying the system information received in step 1f-25 according to the method proposed in step 1f-20. The terminal (1f-01) according to the present disclosure may derive the Rank for each cell according to the method proposed in the aforementioned embodiment 1e or step 1f-25.

[0249] In step 1f-45, the terminal (1f-01) receives system information (e.g., MIB or SIB1) broadcast from the candidate target cell before finally reselecting the candidate target cell, and determines based on the received system information whether both the cell selection reception signal level value (Srxlev) and the cell selection signal quality value (Squal) of the candidate target cell are greater than 0 (i.e., the cell selection criterion is satisfied (Srxlev > 0 AND Squal > 0). If the terminal satisfies the cell selection criterion and the candidate target cell is suitable, the terminal can reselect the candidate target cell.

[0250] FIG. 1g is a diagram for explaining a method for a terminal supporting a low-power wake-up receiver to perform cell reselection in a next-generation wireless communication system according to one embodiment.

[0251] A terminal (1g-01) according to an embodiment of the present disclosure may be equipped with a Main Radio (MR) and a Low Power Wake-Up Receiver (LR) to perform a predetermined operation. The MR (1f-02) equipped in the terminal may refer to a transceiver module (Tx / Rx module operating for NR signals / channels apart from signals / channels related to low-power wake-up) from which low-power wake-up signals / channels are transmitted. For example, the terminal may receive a wake-up signal (WUS) transmitted by a base station through the MR, and based on this, the terminal may determine whether to additionally receive a paging message. Alternatively, the terminal may receive a Synchronization Signal / PBCH block (SSB) transmitted by a base station through the MR, and based on this, the terminal may select or reselect a cell. For reference, a terminal following the aforementioned embodiment 1e refers to a terminal equipped only with MR.

[0252] An additionally mounted LR (1f-03) in the terminal may refer to a receiver module (Rx module) operating for receiving / processing signals / channels related to low-power wake-up. For example, the terminal may receive a low power wake-up signal (LP-WUS) transmitted by a base station through the LR, and based on this, the terminal may determine whether to turn on or off the MR, and thus determine whether to receive the WUS transmitted by the base station or a paging message. Alternatively, the terminal may receive a low power synchronization signal (LP-SS) transmitted by the base station through the LR, and based on this, determine whether to measure neighboring cells or whether LP-WUS reception is possible. Since LP-WUS / LP-SS uses less channel bandwidth and low complex channel coding than WUS / SSB, the power consumed when using LR is less than that of MR, and therefore the terminal can achieve power saving by turning off MR and using LR according to certain conditions. To save power, the terminal can determine whether to turn on or off MR based on a signal related to low-power wake-up received through LR. For reference, the state in which the terminal turns off MR can be referred to as an ultra-deep-sleep state.

[0253] Referring to FIG. 1g, a terminal (1g-01) may be in RRC connected mode (RRC_CONNECTED) by establishing an RRC connection with an NR cell (1g-05) (1g-06).

[0254] In step 1g-07, the terminal (1g-01) may transmit a terminal capability information message (UECapabilityInformation) at the request of the base station (1g-05). The message may include at least one of an indicator indicating whether LR is supported or an indicator indicating that a modified cell reselection procedure can be performed according to LR support.

[0255] In step 1g-08, the NR base station (1g-05) may transmit an RRC connection release message (RRCRelease) to the terminal (1g-01). This may follow at least one of step 1e-04 or step 1f-08 of the aforementioned embodiments. The message may include a frequency-specific cell reselection priority value supporting LP-WUS and / or LP-SS (or, it may be referred to as LP-WUS specific frequency priority per frequency). Alternatively, the message may include an indicator indicating to apply the frequency-specific cell reselection priority value supporting LP-WUS and / or LP-SS (or, it may be referred to as LP-WUS specific frequency priority per frequency) broadcasted in the system information. The message may include a t320 value or a new timer value associated with the indicator and / or the priority value. The terminal may start the timer with the corresponding value. For reference, the frequency-specific cell reselection priority values ​​supporting LP-WUS and / or LP-SS may be signaled as in the above-described embodiment (Fig. 1e) or may be signaled as an offset to the cell reselection priority values ​​derived in the above-described embodiment (Fig. 1e), such that the cell reselection priority values ​​derived in the above-described embodiment (Fig. 1e) plus the values ​​signaled in the present disclosure may be the final cell reselection priority values.

[0256] In step 1g-10, the terminal (1g-01) may transition to RRC idle mode (RRC_IDLE) or RRC inactive mode (RRC_INACTIVE). This may follow step 1e-05 or step 1f-10 of the aforementioned embodiment.

[0257] In step 1g-15, the terminal (1g-01) can receive essential system information broadcast by the NR cell (1g-05) through the MR (1g-02). In the present disclosure, the Master Information Block (MIB) and System Information Block 1 (SIB1) may be referred to as essential system information. The essential system information (MIB or SIB1) may include certain information applicable to a terminal supporting LR. The certain information may mean at least one of the following:

[0258] - Indicator of whether to transmit Low-Power Synchronization Signal (LP-SS) or setting information for LP-SS

[0259] - Indicator of whether to transmit Low-Power Wake-up Signal (LP-WUS) or configuration information for LP-WUS

[0260] - : Minimum signal reception level value required when a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS.

[0261] - : Minimum signal quality level value required when a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS.

[0262] - : Minimum signal reception level offset value required when a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS.

[0263] - : Minimum signal quality level offset value required when a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS.

[0264] In step 1g-20, the terminal (1g-01) can perform a cell selection procedure based on the essential system information received in step 1g-15. The terminal can find an NR suitable cell belonging to the selected PLMN or SNPN and camp on the cell. The definition of a suitable cell can follow the definition mentioned in the aforementioned embodiment 1e. Since a terminal (1g-01) supporting LR can efficiently save power by selecting or reselecting a cell (1g-05) supporting LP-WUS and / or LP-SS, a terminal (1g-01) according to the present disclosure can derive a cell selection reception signal level value (Srxlev) and a cell selection signal quality value (Squal) through at least one of the methods proposed below (i.e., the methods may be combined or only one of the methods may be performed), and if both Srxlev and Squal are greater than 0, it can be determined that a cell selection criterion is fulfilled.

[0265] - Method 1: When a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS, Srxlev and Squal are derived by applying the minimum signal reception level value and minimum quality level value required.

[0266]

[0267] For reference, and The remaining parts, except for applying , may follow the above-described embodiment. At this time, , , , At least one of them may not be applicable to the terminal, in which case the terminal may consider the value as 0 (i.e., the parameter may not be considered in Srxlev and Squal).

[0268] - Method 2: When selecting a cell supporting LP-WUS and / or LP-SS that can be applied by a terminal supporting LR, Srxlev and Squal are derived by applying the minimum signal reception level offset value and the minimum quality level offset value required.

[0269] (Option 1)

[0270]

[0271] (Option 2)

[0272]

[0273] For reference, and The remaining parts, except for the additional application, may follow the above-described embodiment.

[0274] The difference between the two proposed options is that they relatively control the extent to which the terminal preferentially selects cells supporting LP-WUS and / or LP-SS (i.e., Option 1 may cause the terminal to select fewer cells supporting LP-WUS and / or LP-SS, while Option 2 may cause the terminal to select more cells supporting LP-WUS and / or LP-SS). Of course, and Depending on how the range of values ​​that can be signaled is defined, Option 1 and Option 2 may be expressed as one. , , , , , At least one of them may not be applicable to the terminal, in which case the terminal may consider the value as 0 (i.e., the parameter may not be considered in Srxlev and Squal).

[0275] - Method 3: When a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS, the minimum signal reception level value and its offset value are applied, and the minimum quality level value and its offset value are applied to derive Srxlev and Squal.

[0276]

[0277] For reference, and Applying Option 2 proposed in Method 2 may also be applied to the above Method 3.

[0278] The terminal can select a cell by deriving Srxlev and Squal through MR (i.e., a signal / message transmitted by the base station through MR) or through LR (i.e., LP-SS or LP-WUS transmitted by the base station through LR). Alternatively, the terminal can determine whether the cell selection criteria are met based on the aforementioned embodiment 1e through MR, and then additionally determine whether the cell selection criteria are met through the method proposed in the present disclosure through LR to select a cell.

[0279] In step 1g-25, the terminal (1g-01) may obtain system information (e.g., SIB2, SIB3, SIB4, SIB5 or a new SIB) containing cell reselection information from the serving cell (1g-05) to perform a cell reselection evaluation procedure. This may follow step 1f-25 of the aforementioned embodiment. In the present disclosure, the system information may include predetermined information applicable to a terminal supporting LR. The predetermined information may mean at least one of the following. The predetermined information may also be referred to as cell reselection-related configuration information of a terminal supporting LR.

[0280] - Frequency-specific cell reselection priority value supporting LP-WUS and / or LP-SS (or, it can be referred to as LP-WUS specific frequency priority per frequency)

[0281] ■ The above value may be signaled as in the above-described embodiment (Fig. 1e) or may be signaled as an offset to the cell reselection priority value derived in the above-described embodiment (Fig. 1e), such that the cell reselection priority value derived in the above-described embodiment (Fig. 1e) plus the value signaled in the present disclosure may be the final cell reselection priority value.

[0282] - : Minimum signal reception level value required when a terminal supporting LR reselects a cell supporting LP-WUS and / or LP-SS.

[0283] ■ The above values ​​can be signaled by frequency.

[0284] - : Minimum signal quality level value required when a terminal supporting LR reselects a cell supporting LP-WUS and / or LP-SS.

[0285] ■ The above values ​​can be signaled by frequency.

[0286] - : Minimum signal reception level offset value required when a terminal supporting LR reselects a cell supporting LP-WUS and / or LP-SS.

[0287] ■ The above value can be signaled for each cell within each frequency, and at this time, a physical cell identifier (Physical Cell Id, PhyCellId) representing the cell can be signaled.

[0288] - : Minimum signal quality level offset value required when a terminal supporting LR selects a cell supporting LP-WUS and / or LP-SS.

[0289] ■ The above value can be signaled for each cell within each frequency, and at this time, a physical cell identifier (Physical Cell Id, PhyCellId) representing the cell can be signaled.

[0290] - List of cells that are acceptable for terminals supporting LP-WUS and / or LP-SS by frequency

[0291] ■ The above terminal can consider only the cells included in the above list as candidate cells for cell reselection.

[0292] - List of cells that terminals supporting LP-WUS and / or LP-SS by frequency must exclude

[0293] ■ The above terminal may not consider the cells included in the above list as candidate cells for cell reselection.

[0294] - QoffsetLR value for each neighboring cell supporting LP-WUS and / or LP-SS in the frequency to which the serving cell belongs (intra-frequency)

[0295] ■ The above QoffsetLR value is an offset between the serving cell and the surrounding cells within the frequency to which the serving cell belongs. The above value is used when deriving Rank (Mathematical Formula 2) in the above-described embodiment, and can be applied in at least one of the following ways.

[0296] ◆ Method 1: Rn = Qmeas,n - Qoffset - QoffsetLR- Qoffsettemp

[0297] ◆ Method 2: Rn = Qmeas,n - QoffsetLR- Qoffsettemp

[0298] - QoffsetLR value for each neighboring cell supporting LP-WUS and / or LP-SS on different frequencies (inter-frequency) from the serving cell

[0299] ■ The above QoffsetLR value is an offset between the serving cell and the surrounding cells within a different NR frequency from the serving cell. The above value is used when deriving Rank (Mathematical Formula 2) in the above-described embodiment, and can be applied in at least one of the following ways.

[0300] ◆ Method 1: Rn = Qmeas,n - Qoffset - QoffsetLR- Qoffsettemp where Qoffset = + , if is valid, otherwise this equals to

[0301] ◆ Method 2: Rn = Qmeas,n - - QoffsetLR- Qoffsettemp

[0302] ◆ Method 3: Rn = Qmeas,n - QoffsetLR- Qoffsettemp

[0303] The above terminal (1g-01) can perform a cell reselection evaluation process. The cell reselection evaluation process may refer to a series of processes for performing frequency measurements by applying reselection priorities handling and measurement rules for cell reselection, and evaluating cell reselection criteria to reselect a cell.

[0304] In step 1g-30, the terminal (1g-01) according to the present disclosure can determine cell reselection priority through at least one of the methods proposed below (i.e., the methods may be combined or only one method may be performed).

[0305] - Method 1: If the RRC connection release message received in step 1g-08 includes a frequency-specific cell reselection priority value supporting LP-WUS and / or LP-SS, the terminal may apply it to determine the cell reselection priority. If the terminal is running a T320 timer value or a new timer, the terminal may perform the above operation until the timer expires or is stopped. That is, the terminal may not apply the cell reselection priority value broadcasted in the system information.

[0306] - Method 2: If the T320 timer value or new timer value driven by the terminal in step 1g-08 expires or is stopped, or if the frequency-specific cell reselection priority value supporting LP-WUS and / or LP-SS is not set in step 1g-08, the terminal may determine the cell reselection priority by applying the frequency-specific cell reselection priority value supporting LP-WUS and / or LP-SS broadcasted in the system information. In this case, the terminal may determine the cell reselection priority by applying only the frequency-specific cell reselection priority values ​​supporting LP-WUS and / or LP-SS. Of course, if the terminal does not have a cell reselection priority value for LP-WUS and / or LP-SS by frequency, it may determine the cell reselection priority by applying the cell reselection priority value described in the above-described embodiment (Fig. 1e) (i.e., if there is a cell reselection priority value for LP-WUS and / or LP-SS for a specific frequency, apply it, otherwise apply the cell reselection priority value described in the above-described embodiment (Fig. 1e)).

[0307] - Method 3: If an instruction to apply the cell reselection priority values ​​by frequency that support LP-WUS and / or LP-SS broadcasted in the system information is received in step 1g-08, the terminal may determine the cell reselection priority by applying the cell reselection priority values ​​by frequency that support LP-WUS and / or LP-SS broadcasted in the system information. At this time, the terminal may determine the cell reselection priority by applying only the cell reselection priority values ​​by frequency that support LP-WUS and / or LP-SS. Of course, if the terminal does not have a cell reselection priority value for LP-WUS and / or LP-SS by frequency, it may determine the cell reselection priority by applying the cell reselection priority value described in the above-described embodiment (Fig. 1e) (i.e., if there is a cell reselection priority value for LP-WUS and / or LP-SS for a specific frequency, apply it, otherwise apply the cell reselection priority value described in the above-described embodiment (Fig. 1e)). For reference, the above operation can be performed when the T320 timer or the new timer is running (of course, the above operation can also be performed regardless of the timer).

[0308] In step 1g-35, the terminal (1g-01) may perform frequency measurement for cell reselection. This may follow at least one of steps 1e-30 or 1f-35 of the aforementioned embodiments.

[0309] In step 1g-40, the terminal (1g-01) may decide to reselect a cell that satisfies the cell reselection criteria based on the measurement values ​​performed in step 1g-35. This may follow step 1g-40 of the embodiment described above. The terminal (1g-01) according to the present disclosure may derive the signal reception level value (Srxlev) and the signal quality value (Squal) of the neighboring cell by applying the system information received in step 1g-25 according to the method proposed in step 1g-20. The terminal (1g-01) according to the present disclosure may derive the Rank for each cell according to the method proposed in step 1f-40 or step 1g-25 of the embodiment described above.

[0310] In step 1g-45, the terminal (1g-01) receives system information (e.g., MIB or SIB1) broadcast from the candidate target cell before finally reselecting the candidate target cell, and determines based on the received system information whether both the cell selection reception signal level value (Srxlev) and the cell selection signal quality value (Squal) of the candidate target cell are greater than 0 (i.e., the cell selection criterion is satisfied (Srxlev > 0 AND Squal > 0). If the terminal satisfies the cell selection criterion and the candidate target cell is suitable, the terminal can reselect the candidate target cell.

[0311] Figure 1h is a block diagram of a terminal according to one embodiment.

[0312] Referring to the above drawing, the terminal includes an RF (Radio Frequency) processing unit (1h-10), a baseband processing unit (1h-20), a storage unit (1h-30), and a control unit (1h-40).

[0313] The RF processing unit (1h-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1h-10) up-converts the baseband signal provided from the baseband processing unit (1h-20) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1h-10) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. In the drawing, only one antenna is illustrated, but the terminal may be equipped with multiple antennas. In addition, the RF processing unit (1h-10) may include multiple RF chains. Furthermore, the RF processing unit (1h-10) may perform beamforming. For the above beamforming, the RF processing unit (1h-10) can adjust the phase and size of each signal transmitted and received through multiple antennas or antenna elements. In addition, the RF processing unit can perform MIMO and receive multiple layers when performing the MIMO operation.

[0314] The baseband processing unit (1h-20) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the baseband processing unit (1h-20) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (1h-20) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (1h-10). For example, in the case of OFDM (orthogonal frequency division multiplexing), when transmitting data, the baseband processing unit (1h-20) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by performing an inverse fast Fourier transform (IFFT) operation and inserting a cyclic prefix (CP). In addition, when receiving data, the baseband processing unit (1h-20) divides the baseband signal provided from the RF processing unit (1h-10) into OFDM symbol units, restores signals mapped to subcarriers through FFT (fast Fourier transform), and then restores the received bit string through demodulation and decoding.

[0315] The baseband processing unit (1h-20) and the RF processing unit (1h-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (1h-20) and the RF processing unit (1h-10) may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. Furthermore, at least one of the baseband processing unit (1h-20) and the RF processing unit (1h-10) may include a plurality of communication modules to support a plurality of different wireless access technologies. In addition, at least one of the baseband processing unit (1h-20) and the RF processing unit (1h-10) may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include a wireless LAN (e.g., IEEE 802.11), a cellular network (e.g., LTE), etc. Additionally, the different frequency bands may include a super high frequency (SHF) (e.g., 2.NRHz, NRhz) band and a millimeter wave (mm wave) (e.g., 60GHz) band.

[0316] The storage unit (1h-30) stores data such as basic programs, application programs, and setting information for the operation of the terminal. In particular, the storage unit (1h-30) can store information related to a second access node that performs wireless communication using a second wireless access technology. In addition, the storage unit (1h-30) provides the stored data upon request from the control unit (1h-40).

[0317] The control unit (1h-40) controls the overall operations of the terminal. For example, the control unit (1h-40) transmits and receives signals through the baseband processing unit (1h-20) and the RF processing unit (1h-10). In addition, the control unit (1h-40) records and reads data in the storage unit (1h-30). For this purpose, the control unit (1h-40) may include at least one processor. For example, the control unit (1h-40) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs.

[0318] FIG. 1i is a block diagram of a base station according to one embodiment.

[0319] As shown in the above drawing, the base station is configured to include an RF processing unit (1i-10), a baseband processing unit (1i-20), a backhaul communication unit (1i-30), a storage unit (1i-40), and a control unit (1i-50).

[0320] The RF processing unit (1i-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1i-10) up-converts the baseband signal provided from the baseband processing unit (1i-20) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1i-10) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. In the drawing, only one antenna is shown, but the first access node may have multiple antennas. In addition, the RF processing unit (1i-10) may include multiple RF chains. Furthermore, the RF processing unit (1i-10) may perform beamforming. For the above beamforming, the RF processing unit (1i-10) can adjust the phase and magnitude of each signal transmitted and received through multiple antennas or antenna elements. The RF processing unit can perform a downlink MIMO operation by transmitting one or more layers.

[0321] The baseband processing unit (1i-20) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the first wireless access technology. For example, when transmitting data, the baseband processing unit (1i-20) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (1i-20) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (1i-10). For example, in the case of OFDM, when transmitting data, the baseband processing unit (1i-20) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols through IFFT operation and CP insertion. In addition, when receiving data, the baseband processing unit (1i-20) divides the baseband signal provided from the RF processing unit (1i-10) into OFDM symbol units, restores the signals mapped to subcarriers through FFT operation, and then restores the received bit string through demodulation and decoding. The baseband processing unit (1i-20) and the RF processing unit (1i-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (1i-20) and the RF processing unit (1i-10) may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

[0322] The above backhaul communication unit (1i-30) provides an interface for performing communication with other nodes within the network. That is, the backhaul communication unit (1i-30) converts a bit string transmitted from the main base station to another node, such as an auxiliary base station or core network, into a physical signal, and converts a physical signal received from the other node into a bit string.

[0323] The storage unit (1i-40) stores data such as basic programs, application programs, and setting information for the operation of the main base station. In particular, the storage unit (1i-40) can store information on bearers assigned to connected terminals, measurement results reported from connected terminals, and the like. In addition, the storage unit (1i-40) can store information that serves as a judgment criterion for whether to provide or terminate multiple connections to a terminal. In addition, the storage unit (1i-40) provides the stored data at the request of the control unit (1i-50).

[0324] The control unit (1i-50) controls the overall operations of the base station. For example, the control unit (1i-50) transmits and receives signals through the baseband processing unit (1i-20) and the RF processing unit (1i-10) or through the backhaul communication unit (1i-30). In addition, the control unit (1i-50) records and reads data in the storage unit (1i-40). For this purpose, the control unit (1i-50) may include at least one processor.

[0325] A specific example for explaining an embodiment according to the present disclosure is only one combination of each criterion, method, detailed method, and operation, and a base station or a terminal can process signals between each other through a combination of at least two or more of the various techniques described. In addition, at this time, signal processing in a wireless communication system including a terminal may be performed according to a method determined through one or a combination of at least two of the aforementioned techniques. For example, it may be possible to perform a portion of the operation of one embodiment in combination with a portion of the operation of another embodiment.

[0326] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0327] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present disclosure.

[0328] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0329] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0330] In the specific embodiments of the present disclosure described above, components included in the invention are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0331] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a method of operating a UE (user equipment) supporting a low power wake-up receiver (LR) in a wireless communication system, A step of receiving an RRC (Radio Resource Control) connection release message from a base station; A step of receiving system information including cell reselection related setting information of a UE supporting LR from the base station; A step of determining whether a cell supporting a low power wake-up signal (LP-WUS) satisfies a cell selection criterion based on cell reselection-related configuration information of a UE supporting the above LR; and A method comprising the step of performing cell reselection for a cell supporting the LP-WUS according to the above decision.

2. In the first paragraph, the cell reselection related setting information of the UE supporting the LR is: A method comprising: a minimum signal reception level offset value for a cell supporting the LP-WUS; and a minimum signal quality level offset value for a cell supporting the LP-WUS.

3. In the second paragraph, the minimum signal reception level offset value for the cell supporting the LP-WUS and the minimum signal quality level offset value for the cell supporting the LP-WUS are, A method in which each frequency is signaled cell by cell, and signaled together with a physical cell identifier (PCI).

4. A method according to claim 1, further comprising a step of determining a serving frequency with the highest cell reselection priority when a UE supporting the LR selects or reselects a cell supporting the LP-WUS.

5. In paragraph 1, A method further comprising the step of determining a serving frequency as the highest cell reselection priority when the cell reselection related configuration information of a UE supporting the above LR includes an indicator indicating that the serving frequency supports the LP-WUS.

6. In paragraph 1, The RRC connection release message includes an indicator that instructs that when selecting or reselecting a cell supporting the LP-WUS, the frequency to which the cell belongs is to be determined as the highest cell reselection priority; and A method further comprising the step of determining a serving frequency with the highest cell reselection priority based on the above indicator.

7. In paragraph 1, The cell reselection related configuration information of the UE supporting the above LR includes a list of allowed cells, A method further comprising the step of considering only cells included in the above allowable cell list as candidate cells for cell reselection.

8. In paragraph 1, The cell reselection related configuration information of the UE supporting the above LR includes a list of excluded cells, A method further comprising the step of excluding cells included in the above-mentioned excluded cell list from candidate cells for cell reselection.

9. In paragraph 1, The cell reselection-related configuration information of the UE supporting the above LR includes an offset value between the serving cell and the surrounding cells supporting LP-WUS within the frequency to which the serving cell belongs (intra-frequency). The above offset value is used to derive the rank per cell.

10. In paragraph 1, The cell reselection related configuration information of the UE supporting the above LR includes an offset value between the serving cell and the neighboring cell supporting LP-WUS within a different frequency (inter-frequency). The above offset value is used to derive the rank per cell.

11. In paragraph 1, The RRC connection release message includes an indicator indicating to apply a frequency-specific cell reselection priority value supporting LP-WUS or a frequency-specific cell reselection priority value supporting LP-WUS included in the system information; and A method further comprising the step of determining a cell reselection priority based on a frequency-specific cell reselection priority value supporting LP-WUS included in the RRC connection release message or the indicator.

12. In paragraph 1, The cell reselection related configuration information of the UE supporting the above LR includes a frequency-specific cell reselection priority value supporting LP-WUS, and A method further comprising the step of determining a cell reselection priority based on a frequency-specific cell reselection priority value supporting the above LP-WUS.

13. In paragraph 1, Further comprising a step of transmitting a UE Capability information message to the base station, A method according to claim 1, wherein the terminal capability information message includes at least one of an indicator indicating whether LR is supported or an indicator indicating that reselection to a cell supporting the LP-WUS can be performed.

14. In a UE (user equipment) supporting a low power wake-up receiver (LR) in a wireless communication system, a memory for storing one or more instructions; and At least one processor; comprising: said at least one processor executing said one or more instructions; Receive an RRC (Radio Resource Control) connection release message from the base station; Receive system information including cell reselection related configuration information of a UE supporting LR from the base station; Based on the cell reselection related configuration information of the UE supporting the above LR, determine whether a cell supporting a low power wake-up signal (LP-WUS) satisfies a cell selection criterion; and A UE that performs cell reselection for a cell supporting the LP-WUS according to the above decision.

15. In a base station in a wireless communication system, a memory for storing one or more instructions; and At least one processor; comprising: said at least one processor executing said one or more instructions; Transmitting an RRC (Radio Resource Control) disconnection message to a UE (user equipment) supporting a Low Power Wake-Up Receiver (LR); and Transmit system information including cell reselection related configuration information of a UE supporting LR to the above UE, The cell reselection related configuration information of the UE supporting the above LR is used by the base station to determine whether a cell supporting a low power wake-up signal (LP-WUS) satisfies the cell selection criterion.

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