Method and device for network energy saving in wireless communication system

Abstract

This network energy saving method is required in consideration of an NCR according to the introduction of the NCR in a next-generation wireless communication system. Accordingly, the present specification proposes a method and device for network energy saving in a wireless communication system.

Description

Method and device for saving network energy in a wireless communication system

[0001] This specification relates to wireless communications, and more particularly, to a method and device for saving network energy in a wireless communication system.

[0002] A network-controlled repeater (NCR) is an enhancement to conventional RF repeaters, capable of receiving and processing side control information from the network. Side control information, or auxiliary control information, can enable the NCR to perform AF operations more efficiently. Potential benefits include mitigation of unnecessary noise amplification, improved spatial directivity for transmission and reception, and simplified network integration.

[0003] Technologies currently being discussed for network energy conservation include turning cells on and off in the time domain, reducing the number of MIMO layers (Multiple-Input and Multiple-Output layers) in the spatial domain, and reducing the power intensity of data channels in the power domain. Furthermore, a technology is being considered in which base station equipment adjusts the transmission and reception bandwidth in the frequency domain to reduce network power consumption. This operation can be referred to as the bandwidth part (BWP) operation of the base station equipment, and can also be referred to as cell-specific BWP.

[0004] With the introduction of NCR in next-generation wireless communication systems, there is a growing demand for network energy-saving methods that take NCR into account. Therefore, this specification proposes a method and device for reducing network energy in wireless communication systems.

[0005] According to one embodiment, a method performed by a network-controlled repeater (NCR) in a wireless communication system is proposed, the method comprising: transmitting capability information to a base station, the capability information including a capability indicator indicating whether the NCR can enter a sleep state; receiving configuration information from the base station, the configuration information including information related to a discontinuous transmission / discontinuous reception (DTX / DRX) operation for the NCR; receiving downlink control information (DCI) from the base station; and performing the DTX / DRX operation based on the DCI, wherein the DTX / DRX operation is characterized in that at least one of transmission and reception by the NCR is not performed.

[0006] Here, transmission and reception by the NCR include transmission and reception for an access link of the NCR, and the access link may be a link between the NCR and a terminal connected to the NCR.

[0007] Here, the DTX / DRX related information may include at least one of information indicating prohibition of cell reselection while the NCR performs the DTX / DRX operation and information on an RNTI (Radio Network Temporary Identifier) ​​that scrambles a PDCCH (Physical Downlink Control Channel) through which the DCI is transmitted.

[0008] Here, the configuration information is transmitted via an RRC (Radio Resource Control) message, the DCI includes information instructing the NCR to perform the DTX / DRX operation, and the capability information can be transmitted via a control link between the NCR and the base station.

[0009] Here, the DTX / DRX operation may include a timer operation, and the timer operation may include an operation in which, after receiving the DCI, the NCR starts a timer, while the timer is operating, the NCR does not perform at least one of transmission and reception by the NCR, and when the timer expires, the NCR resumes at least one of transmission and reception by the NCR.

[0010] Here, the DCI may include information about the duration of the DTX / DRX operation.

[0011] Here, the step of performing the DTX / DRX operation based on the DCI may include the step of receiving a medium access control-control element (MAC-CE) based on the DCI and the step of performing the DTX / DRX operation based on the MAC-CE.

[0012] Here, the MAC-CE can be transmitted through PDSCH (Physical Downlink Shared Channel).

[0013] Here, the DCI may include information for scheduling the PDSCH.

[0014] Here, the DTX / DRX operation may include a timer operation, and the timer operation may include an operation in which, after receiving the MAC-CE, the NCR starts a timer, while the timer is operating, the NCR does not perform at least one of transmission and reception by the NCR, and when the timer expires, the NCR resumes at least one of transmission and reception by the NCR.

[0015] According to another embodiment, a network-controlled repeater (NCR) is proposed, comprising: one or more memories storing commands; one or more transceivers; and one or more processors connecting the one or more memories and the one or more transceivers, wherein the one or more processors execute the commands to transmit capability information to a base station, the capability information including a capability indicator indicating whether the NCR can enter a sleep state; receive configuration information from the base station, the configuration information including information related to a discontinuous transmission / discontinuous reception (DTX / DRX) operation for the NCR; receive downlink control information (DCI) from the base station, and perform the DTX / DRX operation based on the DCI, wherein the DTX / DRX operation is characterized in that at least one of transmission and reception by the NCR is not performed.

[0016] Here, transmission and reception by the NCR include transmission and reception for an access link of the NCR, and the access link may be a link between the NCR and a terminal connected to the NCR.

[0017] Here, the DTX / DRX related information may include at least one of information indicating prohibition of cell reselection while the NCR performs the DTX / DRX operation and information on an RNTI (Radio Network Temporary Identifier) ​​that scrambles a PDCCH (Physical Downlink Control Channel) through which the DCI is transmitted.

[0018] Here, the configuration information is transmitted via an RRC (Radio Resource Control) message, the DCI includes information instructing the NCR to perform the DTX / DRX operation, and the capability information can be transmitted via a control link between the NCR and the base station.

[0019] Here, the DTX / DRX operation may include a timer operation, and the timer operation may include an operation in which, after receiving the DCI, the NCR starts a timer, while the timer is operating, the NCR does not perform at least one of transmission and reception by the NCR, and when the timer expires, the NCR resumes at least one of transmission and reception by the NCR.

[0020] Here, the DCI may include information about the duration of the DTX / DRX operation.

[0021] Here, the step of performing the DTX / DRX operation based on the DCI may include the step of receiving a medium access control-control element (MAC-CE) based on the DCI and the step of performing the DTX / DRX operation based on the MAC-CE.

[0022] Here, the MAC-CE can be transmitted through PDSCH (Physical Downlink Shared Channel).

[0023] Here, the DCI may include information for scheduling the PDSCH.

[0024] Here, the DTX / DRX operation may include a timer operation, and the timer operation may include an operation in which, after receiving the MAC-CE, the NCR starts a timer, while the timer is operating, the NCR does not perform at least one of transmission and reception by the NCR, and when the timer expires, the NCR resumes at least one of transmission and reception by the NCR.

[0025] According to this specification, power consumption of NCR can be reduced, thereby increasing power savings. Furthermore, the overall network can be stabilized.

[0026] The effects that can be achieved through specific examples of this specification are not limited to the effects listed above. For example, a person with ordinary skill in the relevant technical field may understand or derive various technical effects from this specification. Accordingly, the specific effects of this specification are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of this specification.

[0027] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0028] FIG. 1 is a conceptual diagram illustrating a wireless communication system according to one embodiment of the present invention.

[0029] FIG. 2 is an exemplary diagram showing a 5G system to which a data transmission method according to one embodiment of the present invention can be applied.

[0030] FIG. 3 is a diagram for explaining a resource grid supported by a wireless access technology to which the present invention can be applied.

[0031] FIG. 4 is a diagram for explaining a bandwidth part (BWP) supported by a wireless access technology to which the present invention can be applied.

[0032] FIG. 5 is a diagram illustrating an example of a synchronization signal block (SSB: Sync. Signal Block) in a wireless access technology to which the present invention can be applied.

[0033] Figure 6 illustrates an example conceptual model of a network control relay.

[0034] Figure 7 illustrates an example of a procedure in which cell DTX / DRX is applied.

[0035] FIG. 8 illustrates a conditional handover method in a communication system according to one embodiment of the present invention.

[0036] FIG. 9 illustrates an example of a change in the power state of a base station according to one embodiment of the present specification.

[0037] FIG. 10 is a flowchart illustrating an example of an operating method of an NCR according to one embodiment of the present specification.

[0038] FIG. 11 is a flowchart of an example of an NCR control method for network energy saving according to one embodiment of the present specification.

[0039] Figure 12 illustrates an example of the format of a MAC CE that controls the state or state transition of an NCR.

[0040] FIG. 13 illustrates an example of a format of a MAC CE controlling a state or state transition of the NCR when the NCR Access Link Beam Indication MAC CE of index 287 is used for the MAC CE controlling a state or state transition of the NCR.

[0041] FIG. 14 is a flowchart of an example of an operation method performed by an NCR according to one embodiment of the present specification.

[0042] Figure 15 illustrates a terminal and network node in which an embodiment of the present specification is implemented.

[0043] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Throughout the description of each drawing, similar reference numerals have been used to designate similar components.

[0044] Although the terms "first," "second," "A," "B," etc. may be used herein to describe various components, the components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, the first component could be referred to as the second component, and similarly, the second component could also be referred to as the first component. Furthermore, the term "and / or" includes any combination of multiple related listed items or any one of multiple related listed items.

[0045] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0046] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0047] Unless otherwise defined, the terms used herein, including technical or scientific terms, have the same meanings commonly understood by those of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings within the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0048] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0049] FIG. 1 is a conceptual diagram illustrating a wireless communication system according to one embodiment of the present invention.

[0050] Referring to FIG. 1, a wireless communication system (100) may be composed of a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6).

[0051] Each of the plurality of communication nodes can support at least one communication protocol. For example, each of the plurality of communication nodes can support a communication protocol based on CDMA (Code Division Multiple Access), a communication protocol based on WCDMA (Wideband CDMA), a communication protocol based on TDMA (Time Division Multiple Access), a communication protocol based on FDMA (Frequency Division Multiple Access), a communication protocol based on OFDM (Orthogonal Frequency Division Multiplexing), a communication protocol based on OFDMA (Orthogonal Frequency Division Multiple Access), a communication protocol based on SC (Single Carrier)-FDMA, a communication protocol based on NOMA (Non-Orthogonal Multiple Access), a communication protocol based on SDMA (Space Division Multiple Access), etc.

[0052] A wireless communication system (100) may include a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of user equipments (130-1, 130-2, 130-3, 130-4, 130-5, 130-6).

[0053] The first base station (110-1), the second base station (110-2), and the third base station (110-3) can each form a macro cell. The fourth base station (120-1) and the fifth base station (120-2) can each form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) can be within the coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) can be within the coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) may be within the coverage of the third base station (110-3). The first terminal (130-1) may be within the coverage of the fourth base station (120-1). The sixth terminal (130-6) may be within the coverage of the fifth base station (120-2).

[0054] Here, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as a NodeB, an evolved NodeB, a next generation Node B (gNB), a next generation 6G base station, a Base Transceiver Station (BTS), a radio base station, a radio transceiver, an access point, an access node, a road side unit (RSU), a Digital Unit (DU), a Cloud Digital Unit (CDU), a Radio Remote Head (RRH), a Radio Unit (RU), a Transmission Point (TP), a transmission and reception point (TRP), a relay node, etc. Each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as a terminal, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, etc.

[0055] Each of the plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can support cellular communication (e.g., long term evolution (LTE), advanced LTE-A, New Radio (NR), 6G Radio Access Technology, etc. as specified in the 3rd generation partnership project (3GPP) standard). Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can operate in a different frequency band or can operate in the same frequency band. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can be connected to each other via an ideal backhaul or a non-ideal backhaul, and can exchange information with each other via the ideal backhaul or the non-ideal backhaul. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can be connected to a core network (not shown) via an ideal backhaul or a non-ideal backhaul. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit a signal received from the core network to the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6), and can transmit a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) to the core network.

[0056] Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can support downlink transmission based on OFDM. In addition, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can support uplink transmission based on OFDM or DFT-Spread-OFDM. In addition, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can support MIMO (Multiple Input Multiple Output) transmission (e.g., SU (Single User)-MIMO, MU (Multi User)-MIMO, massive MIMO, etc.), CoMP (Coordinated Multipoint) transmission, carrier aggregation transmission, transmission in an unlicensed band, device to device (D2D) communication (or, ProSe (proximity services), etc.). Here, each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can support base stations (110-1, 110-2, 110-3, It is possible to perform operations corresponding to (120-1, 120-2) and / or operations supported by base stations (110-1, 110-2, 110-3, 120-1, 120-2).

[0057] For example, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) based on the SU-MIMO scheme, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) based on the SU-MIMO scheme. Alternatively, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) and the fifth terminal (130-5) based on the MU-MIMO scheme, and each of the fourth terminal (130-4) and the fifth terminal (130-5) can receive a signal from the second base station (110-2) based on the MU-MIMO scheme. Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can transmit a signal to the fourth terminal (130-4) based on the CoMP scheme, and the fourth terminal (130-4) can receive a signal from the first base station (110-1), the second base station (110-2), and the third base station (110-3) based on the CoMP scheme. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit and receive a signal with terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) within its coverage based on the CA scheme.

[0058] Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can coordinate D2D communication between the fourth terminal (130-4) and the fifth terminal (130-5), and each of the fourth terminal (130-4) and the fifth terminal (130-5) can perform D2D communication through coordination by each of the second base station (110-2) and the third base station (110-3).

[0059] Hereinafter, even if a method (e.g., transmitting or receiving a signal) performed by a first communication node among communication nodes is described, a corresponding second communication node can perform a method (e.g., receiving or transmitting a signal) corresponding to the method performed by the first communication node. That is, if an operation of a terminal is described, a corresponding base station can perform an operation corresponding to the operation of the terminal. Conversely, if an operation of a base station is described, a corresponding terminal can perform an operation corresponding to the operation of the base station.

[0060] Also, in the following, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In downlink, the transmitter may be part of the base station, and the receiver may be part of the terminal. In uplink, the transmitter may be part of the terminal, and the receiver may be part of the base station.

[0061] Recently, with the rapid proliferation of smartphones and Internet of Things (IoT) devices, the amount of information exchanged via communications networks is increasing. Accordingly, next-generation wireless access technologies need to consider environments that provide faster services to more users than existing communication systems (or existing radio access technologies), such as enhanced mobile broadband communication. To this end, the design of communication systems that consider Machine Type Communication (MTC), which connects multiple devices and objects to provide services, is being discussed. Furthermore, the design of communication systems that consider services and / or terminals sensitive to communication reliability and / or latency (e.g., Ultra-Reliable and Low Latency Communication (URLLC)) is also being discussed.

[0062] Hereinafter, in this specification, for the convenience of explanation, the next-generation wireless access technology is referred to as New RAT (Radio Access Technology), and the wireless communication system to which the New RAT is applied is referred to as an NR (New Radio) system. In this specification, the frequency, frame, subframe, resource, resource block, region, band, subband, control channel, data channel, synchronization signal, various reference signals, various signals, or various messages related to NR may be interpreted as having the meaning used in the past or present, or as having various meanings used in the future.

[0063] FIG. 2 is an exemplary diagram showing an NR system to which a data transmission method according to one embodiment of the present invention can be applied.

[0064] 5G, standardized by 3GPP, is a radio access technology that can provide improved data transmission rates compared to LTE and satisfy various QoS requirements for each segmented and specific usage scenario. In particular, eMBB (enhanced Mobile Broadband), mMTC (massive MTC), and URLLC (Ultra Reliable and Low Latency Communications) are defined as representative usage scenarios of NR. A flexible frame structure compared to LTE is provided as a method to satisfy the requirements of each scenario. The frame structure of 5G NR supports a frame structure based on multiple subcarriers. The default subcarrier spacing (SCS) is 15 kHz, and a total of five SCS types are supported: 15 kHz * 2^n (n = 0, 1, 2, 3, 4).

[0065] Referring to Figure 2, the NG-RAN (Next Generation-Radio Access Network) consists of gNBs that provide NG-RAN user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocol termination for UE (User Equipment). Here, NG-C represents the control plane interface used for the NG2 reference point between the NG-RAN and the 5th Generation Core (5GC). NG-U represents the user plane interface used for the NG3 reference point between the NG-RAN and the 5GC.

[0066] gNBs are interconnected via the Xn interface and connected to the 5GC via the NG interface. More specifically, gNBs are connected to the Access and Mobility Management Function (AMF) via the NG-C interface and to the User Plane Function (UPF) via the NG-U interface.

[0067] The NR system of FIG. 2 can support multiple numerologies. Here, the numerologies can be defined by subcarrier spacing and cyclic prefix (CP) overhead. Multiple subcarrier spacings can be derived by scaling the basic subcarrier spacing to integers. Furthermore, even if it is assumed that very low subcarrier spacing is not utilized at very high carrier frequencies, the numerologies utilized can be selected independently of the frequency band.

[0068] Additionally, the NR system can support various frame structures according to multiple numerologies.

[0069] Below, the NR waveform, numerology, and frame structure are described.

[0070] NR uses the CP-OFDM waveform with a cyclic prefix for downlink transmission, and CP-OFDM or DFT-S-OFDM for uplink transmission. OFDM technology is easily combined with MIMO (Multiple Input Multiple Output) and offers the advantages of high frequency efficiency and low-complexity receivers.

[0071] Meanwhile, in NR, the requirements for data rates, latency, and coverage differ across the three scenarios mentioned above. Therefore, it is necessary to efficiently satisfy these requirements across the frequency bands that comprise any NR system. To this end, technologies have been proposed to efficiently multiplex radio resources based on multiple different numerologies.

[0072] Specifically, the NR transmission numerator is determined based on the sub-carrier spacing and the cyclic prefix (CP), and is changed exponentially using the μ value as an exponent value of 2 based on 15 kHz, as shown in Table 1 below.

[0073] μSubcarrier spacing (kHz)Cyclic prefixSupported for dataSupported for synch015NormalYesYes130NormalYesYes260Normal, ExtendedYesNo3120NormalYesYes4240NormalNoYes

[0074] As shown in Table 1 above, the numerology of NR can be divided into five types according to the subcarrier spacing. This is different from the fixed 15 kHz subcarrier spacing of LTE, one of the 4G communication technologies. Specifically, the subcarrier spacing used for data transmission in NR is 15, 30, 60, and 120 kHz, and the subcarrier spacing used for synchronization signal transmission is 15, 30, 120, and 240 kHz. In addition, the extended CP is applied only to the 60 kHz subcarrier spacing. Meanwhile, the frame structure in NR is defined as a 10 ms frame consisting of 10 subframes of the same length of 1 ms. One frame can be divided into 5 ms half frames, and each half frame contains 5 subframes. For a 15 kHz subcarrier spacing, one subframe consists of one slot, and each slot consists of 14 OFDM symbols.

[0075] Below, NR physical resources are described.

[0076] In relation to physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, and bandwidth parts are considered.

[0077] Antenna ports are defined such that the channel through which a symbol on an antenna port is carried can be inferred from the channel through which another symbol on the same antenna port is carried. Two antenna ports are said to be quasi co-located (QC / QCL) if the large-scale properties of the channel through which a symbol on one antenna port is carried can be inferred from the channel through which a symbol on the other antenna port is carried. Here, the large-scale properties include one or more of delay spread, Doppler spread, Doppler shift, average delay, and spatial Rx parameters.

[0078] FIG. 3 is a diagram for explaining a resource grid supported by a wireless access technology to which the present invention can be applied.

[0079] Referring to Figure 3, a resource grid may exist for each numeral, as NR supports multiple numerals on the same carrier. Furthermore, resource grids may exist based on antenna ports, subcarrier spacing, and transmission direction.

[0080] A resource block (RB) consists of 12 subcarriers and is defined solely in the frequency domain. Furthermore, a resource element (RE) consists of one OFDM symbol and one subcarrier. Therefore, as shown in Figure 3, the size of a single RB can vary depending on the subcarrier spacing. NR also defines "Point A," which serves as a common reference point for the RB grid, as well as common RBs and physical RBs.

[0081] FIG. 4 is a diagram for explaining a bandwidth part supported by a wireless access technology to which the present invention can be applied.

[0082] Unlike LTE, where the carrier bandwidth is fixed at 20 MHz, NR sets the maximum carrier bandwidth from 50 MHz to 400 MHz for each subcarrier interval. Therefore, it is not assumed that all terminals will use the entire carrier bandwidth. Accordingly, NR allows terminals to designate bandwidth parts (BWPs) within the carrier bandwidth, as illustrated in Figure 4. Furthermore, bandwidth parts are associated with a single numerology, consist of a subset of consecutive common resource blocks, and can be dynamically activated over time. Each terminal is configured with up to four bandwidth parts for both the uplink and downlink, and data is transmitted and received using the bandwidth parts activated at a given time.

[0083] In the case of a paired spectrum, the uplink and downlink bandwidth parts are set independently, and in the case of an unpaired spectrum, the downlink and uplink bandwidth parts are set in pairs so that they can share a center frequency to prevent unnecessary frequency re-tuning between downlink and uplink operations.

[0084] Below, the initial connection to NR is described.

[0085] In NR, a terminal performs cell search and random access procedures to connect to a base station and perform communication.

[0086] Cell search is a procedure in which a terminal synchronizes to the cell of a corresponding base station, obtains a physical layer cell ID, and obtains system information using a synchronization signal block (SSB) transmitted by the base station.

[0087] FIG. 5 is a diagram illustrating an example of a synchronization signal block in a wireless access technology to which the present invention can be applied.

[0088] Referring to FIG. 5, SSB is composed of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS), each occupying one symbol and 127 subcarriers, and a PBCH spanning three OFDM symbols and 240 subcarriers.

[0089] The terminal receives SSB by monitoring SSB in the time and frequency domain.

[0090] SSB can be transmitted up to 64 times in 5ms. Multiple SSBs are transmitted in different transmission beams within 5ms, and the terminal performs detection assuming that SSBs are transmitted every 20ms based on a specific beam used for transmission. The number of beams that can be used for SSB transmission within 5ms can increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted below 3GHz, up to 8 in the frequency band between 3GHz and 6GHz, and up to 64 different beams can be used for SSB transmission in the frequency band above 6GHz.

[0091] SSB contains two symbols in one slot, and the starting symbol and number of repetitions within the slot are determined as follows depending on the subcarrier spacing.

[0092] Meanwhile, unlike SS in conventional LTE, SSB is not transmitted at the center frequency of the carrier bandwidth. This means that SSB can be transmitted even in locations other than the center of the system bandwidth, and when supporting wideband operation, multiple SSBs can be transmitted in the frequency domain. Accordingly, the terminal monitors SSB using the synchronization raster, which is a candidate frequency location for monitoring SSB. The carrier raster, which is the center frequency location information of the channel for initial access, and the synchronization raster are newly defined in NR. The synchronization raster has a wider frequency interval than the carrier raster, which can support the terminal's fast SSB search.

[0093] A UE can obtain the MIB through the PBCH of the SSB. The MIB (Master Information Block) includes the minimum information required for the UE to receive the remaining system information (RMSI, Remaining Minimum System Information, or SIB1 (System Information Block 1)) broadcast by the network. In addition, the PBCH may include information on the position of the first DM-RS (demodulation reference signal) symbol in the time domain, information for the UE to monitor SIB1 (e.g., SIB1 numerology information, information related to SIB1 CORESET, search space information, PDCCH (physical downlink control channel) related parameter information, etc.), offset information between the common resource block and the SSB (the absolute position of the SSB within the carrier is transmitted through SIB1), etc. Here, the SIB1 numerology information is also applied equally to some messages used in the random access procedure for the UE to access the base station after completing the cell search procedure. For example, the numerology information of SIB1 may be applied to at least one of messages 1 to 4 for a random access procedure.

[0094] The aforementioned RMSI may refer to SIB1 (System Information Block 1), and SIB1 is broadcast periodically (e.g., every 160 ms) in the cell. SIB1 contains information necessary for the UE to perform the initial random access procedure and is periodically transmitted via PDSCH. In order for the UE to receive SIB1, it must receive numerology information used for SIB1 transmission and CORESET (Control Resource Set) information used for SIB1 scheduling via PBCH. The UE checks scheduling information for SIB1 using SI-RNTI in CORESET and acquires SIB1 on PDSCH according to the scheduling information. The remaining SIBs, excluding SIB1, may be transmitted periodically or upon request of the UE.

[0095] Below, a network-controlled repeater (NCR) is described.

[0096] Coverage is a fundamental aspect of cellular network deployment. Mobile operators rely on different types of network nodes to provide uniform coverage during deployment. While deploying standard full-stack cells is an option, it may not always be feasible (e.g., due to unavailability of backhaul) or economically viable.

[0097] One way to improve coverage is to use relay nodes. Relay nodes can receive signals from a base station or a Transmission and Reception Point (TRP) and forward them to a terminal, or conversely, receive signals from a terminal and forward them to a base station or a TRP. The received signal of the relay node can be amplified or beamformed and then retransmitted to the other node, thereby expanding the signal's coverage. Relay nodes can be classified into various types depending on their function. An amplify-and-forward (AF) relay can simply amplify the received signal and retransmit it. An AF relay can be referred to as an L1 (layer 1) relay or a repeater. A decode-and-forward (DF) relay can decode the received signal to receive data and then re-encode and transmit it. DF relays can include L2 (layer 2) relays and L3 (layer 3) relays. An integrated access and backhaul (IAB) node can be functionally classified as an L3 relay.

[0098] Among the relay node types listed above, repeaters have a simple structure and operation, allowing for low-cost production and delivering high efficiency relative to the investment. Basic repeaters typically do not distinguish between uplink and downlink and may not perform beamforming. However, to maximize coverage expansion, it may be desirable for repeaters to support beamforming.

[0099] As a result, new types of network nodes have been considered to increase the flexibility of mobile operators' network construction. For example, Integrated Access and Backhaul (IAB) has been introduced, strengthening a new type of network node that does not require wired backhaul. Another type of network node is the Radio Frequency (RF) repeater, which simply amplifies and forwards all the signals it receives. RF repeaters have been widely deployed in various wireless communication systems to supplement the coverage provided by conventional full-stack cells. In NR, RF and electromagnetic compatibility (EMC) requirements for RF repeaters targeting both FR1 and FR2 have been specified.

[0100] RF repeaters offer a cost-effective means of extending network coverage, but they have limitations. They simply perform amplify-and-forward (AF) operation, failing to consider various factors that could enhance performance. These factors may include information about semi-static and / or dynamic downlink / uplink configurations, adaptive transceiver spatial beamforming, and ON-OFF states.

[0101] A network-controlled repeater (NCR) is an enhancement to conventional RF repeaters, capable of receiving and processing side control information from the network. Side control information, or auxiliary control information, can enable the NCR to perform AF operations more efficiently. Potential benefits include mitigation of unnecessary noise amplification, improved spatial directivity for transmission and reception, and simplified network integration.

[0102] Figure 6 illustrates an example conceptual model of a network control relay.

[0103] The network control relay can be modeled as shown in Figure 6, including NCR-MT (Mobile Termination) and NCR-Fwd (Forwarding). NCR-MT can be defined as a functional entity that communicates with the base station / gNB via the C-link (Control Link) to enable information exchange (e.g., side control information for NCR-Fwd control). The C-link can be based on the NR Uu interface.

[0104] NCR-Fwd can be defined as a functional entity that performs AF operations for UL / DL RF signals between the gNB and the terminal via the backhaul link and access link. The operation of NCR-Fwd can be controlled based on side control information received from the gNB.

[0105] NCR-MT performs communication between the base station and the NCR. The control link is a link formed between the base station and the NCR-MT, and performs the configuration and control of the NCR's access link and / or backhaul link. The backhaul link is a link formed between the NCR-Fwd and the base station, and a signal transmitted from the base station to the terminal through this link can be transmitted and amplified by the NCR-Fwd, and a signal received from the terminal to the NCR-Fwd can be amplified and transmitted to the base station through this link. The access link is a link formed between the NCR-Fwd and the terminal / UE, and a signal between the base station and the UE can be amplified through this link.

[0106] For example, in NCR, the access link of NCR-Fwd can be turned on / off implicitly. For example, when resources are allocated for a specific beam, the operation / procedure can implicitly instruct to turn on the access link. Furthermore, when an error / failure occurs in the NCR-Fwd link due to reasons such as a radio link failure (RLF) with the base station, the operation / procedure can implicitly instruct to turn off the link.

[0107] With respect to network energy saving, the DRX operation of the terminal may be considered. The DRX cycle of the terminal may utilize an active mode for data exchange processing and an inactive sleep mode. The terminal may utilize the active mode for processing at defined intervals to perform measurements related to network conditions or to transmit and receive signals / channels. The period during which the terminal may be scheduled to receive may be referred to as an on period or DRX active time for the DRX cycle. If an on period is not scheduled during the DRX cycle, the terminal may utilize the inactive sleep mode and have the opportunity to save power. This period may be referred to as a DRX inactive time or an off period.

[0108] Technologies currently being discussed for network energy conservation include turning cells on and off in the time domain, reducing the number of MIMO layers (Multiple-Input and Multiple-Output layers) in the spatial domain, and reducing the power intensity of data channels in the power domain. Furthermore, a technology is being considered in which base station equipment adjusts the transmission and reception bandwidth in the frequency domain to reduce network power consumption. This operation can be referred to as the bandwidth part (BWP) operation of the base station equipment, and can also be referred to as cell-specific BWP.

[0109] In particular, a method of controlling a base station by turning it on or off for a specific period of time may be considered, and the method may be named cell DTX / DRX (discontinuous transmission / discontinuous reception). Cell DTX / DRX may utilize on periods during which the base station can transmit / receive signals / channels and off periods during which the base station can disable some or all types of signal reception / transmission processing and save power. Here, the method may be periodic, i.e., applied periodically, or applied aperiodically.

[0110] Figure 7 illustrates an example of a procedure in which cell DTX / DRX is applied.

[0111] Referring to FIG. 7, the base station may transmit RRC signaling to terminal(s) (S710). Here, for example, the RRC signaling may be a message related to RRC connection / configuration / reconfiguration, such as RRC reconfiguration. Here, the RRC signaling may include at least some of cell DTX / DRX configuration information, conditional handover (CHO) configuration information, and RNTI (Radio Network Temporary Identifier) ​​for indicating cell DTX / DRX operation (in this specification, the RNTI may be referred to as cellDTRX-RNTI). For example, the base station may transmit cell DTX / DRX configuration information to terminal(s) capable of performing cell DTX / DRX operation. Here, the cell DTX / DRX configuration information may include information about a cycle for cell DTX / DRX, an offset of the cycle compared to a reference time, an on-duration timer (e.g., a timer indicating the time that the terminal or base station / cell is awake), etc. In addition, when there is no signal transmission as the cell DTX / DRX operation is performed, the terminal may need to perform a handover operation to another cell due to the disappearance of the signal of the serving cell. In this case, the terminal may need to perform a conditional handover in which the handover is performed by determining a target cell without connectivity with the serving cell. Therefore, for such a case, a separate conditional handover triggering condition may be set, and a function / setting capable of performing CHO may be required when performing the cell DTX / DRX operation via PDCCH. Therefore, the base station may transmit parameters related to at least some of the cell DTX / DRX operation and CHO to the terminal(s) capable of performing the cell DTX / DRX operation.

[0112] For example, cell DTX / DRX configuration information can be configured as shown in Tables 2 and 3 below. Meanwhile, Tables 2 and 3 are only examples of cell DTX / DRX configuration information, and the cell DTX / DRX configuration information proposed in this specification is not limited to Tables 2 and 3.

[0113]

[0114]

[0115] Table 4 shows an example of CHO-related parameters that can be set in relation to cell DTX / DRX operations. Table 4 is only an example, and the CHO-related parameters proposed in this specification are not limited to Table 4.

[0116]

[0117] For example, a specific DCI format (e.g., DCI format 2_9, a newly defined DCI format, etc.) may be used for cell DTX / DRX, CHO activation / deactivation. To distinguish the DCI format, the base station may use a special RNTI, which may be named cellDTRX-RNTI. The cellDTRX-RNTI may be applied to only one terminal or to multiple terminals.

[0118] Thereafter, the base station can transmit a PDCCH to the terminal(s) (S720). Here, as an example, the base station can transmit information related to the specific DCI format (e.g., DCI format 2_9, a newly defined DCI format, etc.) through the PDCCH scrambled via cellDTRX-RNTI. The specific DCI format can include information indicating activation / deactivation of cell DTX / DRX, information indicating activation of conditional handover according to cell DTX / DRX activation, etc. Here, as an example, the cellDTRX-RNTI can be commonly set to a plurality of terminals, and information related to the specific DCI format can be transmitted to the plurality of terminals via one PDCCH.

[0119] Thereafter, the base station can perform cell DTX / DRX operation (S730). Here, the base station can transmit activation / deactivation information for cell DTX / DRX to the terminal, and then deactivate / activate transmission and reception based on the cycle and on-duration timer determined in step S710.

[0120] Thereafter, the terminal can perform the terminal DTX / DRX operation (S740). Here, the terminal can deactivate / activate transmission and reception based on the cycle and on-duration timer determined in step S710. For example, when the terminal DRX operation is activated, the terminal may turn off RF or not perform an operation to receive PDCCH in order to prevent power consumption due to reception. As another example, when the terminal DTX operation is activated, the terminal may turn off RF or not perform transmission of PRACH (physical random access channel), SR (scheduling request), PUCCH (physical uplink control channel), etc. in order to prevent power consumption due to transmission. Here, the terminal DTX / DRX operation may correspond to the DTX / DRX operation described below.

[0121] Below, Conditional Handover (CHO) is explained.

[0122] Conditional Handover (CHO) is defined as a handover initiated by a terminal (UE) when one or more handover conditions are met. After receiving the configuration of a conditional handover, the UE begins evaluating the execution conditions and, once the handover is executed, stops evaluating the execution conditions (either legacy handover or conditional handover execution).

[0123] FIG. 8 illustrates a conditional handover method in a communication system according to one embodiment of the present invention.

[0124] Referring to FIG. 8, the communication system may include a terminal (810), a source base station (or cell) (830), a first neighbor / target base station (or cell) (850), and a second neighbor / target base station (or cell) (870).

[0125] The terminal (810) may be one of the terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) illustrated in FIG. 1, and the source base station (830), the first neighboring base station (850), and the second neighboring base station (870) may each be one of the base stations (110-1, 110-2, 110-3, 120-1, 120-2) illustrated in FIG. 1.

[0126] The terminal (810) may be connected to the source base station (830). For example, the terminal (810) may operate in an RRC (radio resource control) connected state and may transmit and receive data with the source base station (830).

[0127] Referring to FIG. 8, the source base station (S830) transmits a measurement configuration message to the terminal (810) (S810).

[0128] At this time, the measurement configuration message may include a threshold for triggering a measurement report message for determining a target cell for handover. The measurement configuration message may also include further measurement event criteria.

[0129] At this time, the measurement configuration message transmitted from the source base station (830) to the terminal (810) may be an RRC message (e.g., an RRC connection reconfiguration message) including measurement configuration information.

[0130] At this time, the terminal (810) can confirm the measurement configuration information by receiving an RRC message from the source base station (830).

[0131] Meanwhile, the terminal (810) performs measurements on the cell and can determine whether the measurement event criteria are met based on the measurement results and the threshold. If the measurement event criteria are met, the terminal transmits a measurement report message to the source base station (830) (S820). For example, the terminal (810) can transmit a measurement report to the source base station (830) when the serving cell quality of the source base station (830) falls below a pre-configured threshold.

[0132] Meanwhile, the source base station (830) determines conditional handover after receiving a measurement report from the terminal (810) (S830).

[0133] The source base station (830) that has decided on a conditional handover transmits a handover request message to each of the first and second neighboring base stations (850, 870) (S840, S845).

[0134] The first and second neighboring base stations (850, 870) each perform approval control procedures (S850, S855).

[0135] Next, when the first and second neighboring base stations (850, 870) accept the handover request from the source base station (830), they transmit an acknowledgement message to the source base station (830) (S860, S865).

[0136] Next, the source base station (830) transmits a conditional handover (CHO) command message to the terminal (810) (S870).

[0137] Next, the terminal (810) starts evaluating the trigger conditions to determine whether the trigger conditions for the conditional handover command message received from the source base station (830) are met (S880).

[0138] If the terminal (810) determines that the trigger condition is met, it applies the corresponding conditional handover command to connect to the target cell (S890). For example, if it decides to handover to the first neighboring base station (850), it performs a handover to the first neighboring base station (850) and connects.

[0139] FIG. 9 illustrates an example of a change in the power state of a base station according to one embodiment of the present specification. The example of FIG. 9 may be an example of cell DTX / DRX (discontinuous transmission / discontinuous reception) or DTX / DRX disclosed in the present specification.

[0140] Referring to FIG. 9, a base station performing wireless communication with a user equipment (UE), terminal, and / or NCR may be powered on or powered off depending on the time. That is, the base station may be in an on state / wake-up state or an off state / sleep state depending on the time. The base station of FIG. 9 may be capable of communicating with the user equipment only when it is in an on state. Here, the off state may correspond to the cell sleep state described above.

[0141] If a base station equipment is off for a long period of time, the NCR-MT cannot accurately determine the time the base station has been off. In this case, the NCR-MT or NCR may remain on, and even if the NCR-MT or NCR remains on, it may reselect a cell other than the original cell (or the original base station). Therefore, a method is needed for the NCR to obtain information about the time the base station is on and to prevent cell reselection to a different base station.

[0142] Below, the methods proposed through this specification are described.

[0143] This specification proposes a method for more efficient power savings by synchronizing an NCR with a base station when the base station performs on / off operations to save network power. If the access link of NCR-Fwd is turned on / off using the existing implicit method, the initial access procedure will be performed frequently according to the cycle, which may waste NCR power consumption. In addition, if the serving base station of the NCR is turned off, the NCR will connect to another base station, which may hinder overall network stability.

[0144] Hereinafter, the method proposed in this specification will be described with reference to the drawings. Fig. 10 is a flowchart illustrating an example of an operating method of an NCR according to one embodiment of the present specification. Specifically, Fig. 10 illustrates a process of controlling an access link BWP of an NCR through a medium access control-control element (MAC-CE) indicated by an NCR-G (group)-RNTI or C (cell)-RNTI proposed in this specification.

[0145] Referring to Figure 10, NCR MT(s) can transmit capability information to the base station (S1010). Here, the NCR can transmit information indicating that it is an NCR to the base station through the capability information. Additionally, if the NCR-Fwd supports multiple frequency bands (or bands), information regarding possible combinations of bands can be included in the capability information.

[0146] The base station may transmit RRC signaling to the NCR-MT(s) (S1020). Here, for example, the RRC signaling may be a message related to RRC connection / establishment / reestablishment, such as RRC reconfiguration. For example, the base station may configure at least some of the following information to the NCR-MT via the RRC reconfiguration message.

[0147] - Information about cellDTRX-RNTI: When the base station performs cell DTX / DRX operation to save energy, cellDTRX-RNTI can be used when scrambling the PDCCH used to inform the terminal whether to activate / deactivate the cell DTX / DRX operation. Here, as an example, the PDCCH can include DCI format 2_9 information.

[0148] - Cell DTX / DRX configuration information: The cell DTX / DRX configuration information may include time configuration information for performing the cell DTX / DRX operation. For example, the cell DTX / DRX configuration information may include information about an on-duration timer. This refers to a time during which the cell DTX / DRX is not performed. That is, during that time, the RF is turned on and the cell performs TX / RX. Therefore, the terminal may also need to be ready to communicate with the base station during that time.

[0149] For example, the cell DTX / DRX configuration information may include information about a periodicity. Cell DTX / DRX operations may have a period, i.e., may be performed periodically. In this case, the on-duration timer may indicate the minimum time for which the cell remains awake within the period.

[0150] For example, the cell DTX / DRX configuration information may include information about an offset. Here, the offset may indicate a start time at which a cycle of cell DTX / DRX operation begins based on a system frame number (SFN).

[0151] At this time, the period during which transmission and reception are possible in the cell through HARQ (hybrid automatic repeat request) retransmission, etc., while being awake at least through the on-duration timer, can be named an on period, and conversely, the period during which transmission and reception are not possible in the cell can be named an off period.

[0152] - Information about CHO settings: Network power saving triggering condition indicator information can be transmitted through information about the CHO settings. If information about the CHO settings is included in the RRC signaling, the NCR-MT can perform a measurement report for conditional handover at the moment when cell DTX / DRX operation is activated.

[0153] - Information about the Temporary Access Barring indicator: For NCR-MT, this indicator can be set to prevent access to another serving cell for network stabilization. When this indicator is set, NCR-MT may not attempt to camp / access to another base station even if there is no signal if the current serving base station is not transmitting due to cell DTX / DRX operation. Therefore, power consumption may not occur. In addition, unnecessary waste of resources such as PRACH and PUCCH can be prevented.

[0154] - Information about On-durationExt-RNTI: The On-durationExt-RNTI may be an RNTI used when scrambling a PDCCH that includes information for extending the on period of a cell DTX / DRX operation.

[0155] Thereafter, the base station can transmit a PDCCH to the NCR-MT(s) (S1030). Here, the NCR-MT(s) can receive a PDCCH scrambled with cellDTRX-RNTI from the base station. Here, the PDCCH can include information on DCI format 2_9, and the information on the DCI format 2_9 can include an activation / deactivation indicator of cell DTX / DRX and / or CHO. Based on the PDCCH, the base station can activate or deactivate the cell DTX / DRX operation set to the NCR-MT(s) through step S1020.

[0156] Thereafter, a DTX / DRX operation may be performed based on the PDCCH (S1040). Here, the DTX / DRX operation may include an NCR-MT DTX / DRX operation. Depending on the cell DTX / DRX setting, the NCR-MT may also perform a DRX / DTX operation (i.e., an NCR-MT DTX / DRX operation) periodically or aperiodically for communication with the base station. For example, when the cell DTX operation is performed, the NCR-MT performs a DRX operation, and therefore, the NCR-MT may not monitor the PDCCH, etc. during the off period. As another example, when the cell DRX operation is performed, the NCR-MT may not transmit a PUCCH, a PRACH, an SR, etc. during the off period.

[0157] In addition, the DTX / DRX operation may include an NCR-Fwd access link DTX / DRX operation. The NCR-Fwd may perform the DTX / DRX operation (i.e., the NCR-Fwd access link DTX / DRX operation) periodically or aperiodically depending on the cell DTX / DRX configuration for the access link (i.e., the link between the NCR-Fwd and the terminal). For example, when the cell performs the DTX operation and thus has an off period, the NCR-Fwd may turn off the access link. That is, the NCR-Fwd may turn off the transmit RF for the access link and not perform transmission. In another example, when the cell performs the DRX operation and thus has an off period, the NCR-Fwd may turn off the receive RF for the access link and not perform reception.

[0158] For example, a cell DTX / DRX operation may include activation of a base station for transmitting and receiving signals during an on period (i.e., a cell-on period) associated with the cell DTX / DRX operation on a cell on which the NCR has camped (i.e., cell-activation) and deactivation of a base station for transmitting and receiving signals during an off period (i.e., a cell-off period) associated with the cell DTX / DRX operation on a cell on which the NCR has camped (i.e., cell-deactivation). Furthermore, a DTX / DRX operation performed by the NCR may include activation of an access link based on activation of a base station for transmitting and receiving signals during an on period associated with the DTX / DRX operation (i.e., cell-activation) and deactivation of a access link based on deactivation of a base station for transmitting and receiving signals during an off period associated with the DTX / DRX operation (i.e., cell-deactivation). Here, the cell-on period and the on period associated with the DTX / DRX operation may be identical. In addition, the cell-off period and the off period associated with the DTX / DRX operation may be identical. Alternatively, the cell-on period and the cell-off period and the on period and off period associated with the DTX / DRX operation may be different from each other.

[0159] Here, when the NCR-Fwd access link supports multiple bands, the DTX / DRX operation for the NCR-Fwd access link can be adjusted for each band. In addition to the on-duration timer, the on-duration of the base station can be extended by HARQ retransmission using drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, drx-RetransmissionTimerSL, etc., RACH resolution or RACH contention resolution using ra-ContentionResolutionTimer, msgB-ResponseWindow, etc. With regard to the extension of the on-duration, at least some of the following methods can be applied.

[0160] - Method 1: Extend the on period for the maximum extendable time.

[0161] For example, if the number of HARQ retransmissions is maximum, i.e., the on period may be extended based on the maximum number of HARQ retransmissions performed. For example, if the maximum number of HARQ retransmissions is set to 8, the on period may be extended by the amount of time corresponding to the completion of the 8 retransmissions.

[0162] Here, for example, the on period can be extended by a time indicated by a specific parameter or information element (IE), for example, Ra-ContentionResolutionTimer, msgB-ResponseWindow, etc.

[0163] - Method 2: A method of extending the on period by the retransmission time and RACH resolution time, and then further extending the on period after monitoring the PDCCH signal.

[0164] For example, after extending the on period by default by the time indicated by a specific parameter or information element (IE), such as RetransmissionTimer (DL / UL / SL), ra-ContentionResolutionTimer, msgB-ResponseWindow timer, etc., the NCR-MT may monitor the PDCCH and, if a PDCCH is present, may additionally extend the on period by the time indicated by the PDCCH.

[0165] At this time, the PDCCH may not be a PDCCH scrambled by the C-RNTI or cellDTRX-RNTI corresponding to the NCR-MT. In other words, the PDCCH may be a PDCCH of another terminal.

[0166] - Method 3: Extending the on period by a new PDCCH.

[0167] Extension of the on-duration may be performed by a new PDCCH. Here, as an example, the new PDCCH may be a PDCCH scrambled by an RNTI defined to extend the on-duration. Here, the RNTI may be named "on-durationExt-timer-RNTI." Additionally, the PDCCH may be scrambled by the on-durationExt-timer-RNTI set through step S1020.

[0168] The PDCCH may be configured in a new DCI format (e.g., DCI format 2_10). Here, at least one of the following pieces of information may be included in the PDCCH.

[0169] - Information about the extension timer: The above information can indicate the time to be extended.

[0170] - Retransmission Indicator or Retransmission Information: An indicator / information indicating the presence of a HARQ retransmission may be included in the corresponding PDCCH. Upon receipt of this indicator / information, the retransmission timer may be restarted, extending the on period.

[0171] - Ra-Contention Indicator: An indicator indicating that Ra-Contention has occurred may be included in the PDCCH. Upon receiving this information, the Ra-ContentionResolutionTimer may be restarted, extending the on period.

[0172] - msgB-Response Indicator: An indicator indicating that a msgB response has occurred may be included in the PDCCH. Upon receipt of this information, a new msgB-ResponseWindow may be started, extending the on period.

[0173] For example, NCR-MT may operate based on the indication / signal of temporary access suppression through step S1010. As another example, NCR-MT may perform the operation by default. NCR-MT may not perform the initial cell camping operation depending on the operation during the off period in cell DTX / DRX. That is, during the off period, NCR-MT maintains its serving cell and performs DTX / DRX operation only for NCR-Fwd, and may detect connectivity with the serving base station during the on period to check whether RLF, etc. occurs. That is, even if there is no signal from the serving base station during the off period, NCR-MT may not declare RLF and may not perform reestablishment to another cell.

[0174] Meanwhile, as another example of network energy saving, a method of controlling a base station by turning it on or off for a specific period of time can be considered, and the method can be named cell DTX / DRX (discontinuous transmission / discontinuous reception) or DTX / DRX. Cell DTX / DRX can utilize on periods during which the base station can transmit / receive signals / channels and off periods during which the base station can disable some or all types of signal reception / transmission processing and save power. Here, the method can be periodic, i.e., applied periodically, or applied aperiodically.

[0175] As an example for saving network energy, when the amount of traffic decreases, such as during the early morning hours, the base station device and / or the RF of the base station may be turned off for a long period of time. In addition, in the case of a store visited by many customers, such as a department store or a large mart, the base station device and / or the RF of the base station serving the store may be turned off for a long period of time outside of the store's business hours. Here, in this specification, the state in which the base station is turned off as described above is referred to as a cell sleep state or sleep state. That is, the off period of the cell DTX / DRX may correspond to the sleep state.

[0176] Referring to FIG. 10, NCR MT(s) can transmit capability information to a base station (S1010). Here, the capability information can be transmitted via a control link (or control link) between the NCR-MT and the base station. In addition, the capability information can include information or an indicator indicating that the entity transmitting the capability information is an NCR. In addition, the capability information can include an indicator / information indicating that the NCR has the capability to enter a sleep state and / or an indicator / information indicating that the NCR can perform a sleep operation.

[0177] The base station may transmit RRC signaling to the NCR-MT(s) (S1020). Here, for example, the RRC signaling may be a message related to RRC connection / establishment / reestablishment, such as RRC reconfiguration. Alternatively, the RRC signaling may be a newly defined RRC message for network energy conservation. For example, in step S1020, the base station may set at least some of the following information to the NCR-MT through the RRC reconfiguration message.

[0178] - Indicator / information indicating prohibition of cell reselection for NCR sleep state: In case of NCR, it is necessary to prevent cell reselection to another serving cell for network stabilization. To this end, an indicator or information indicating prohibition of cell reselection for NCR sleep state can be defined / set. When the indicator / information is set, the terminal may not attempt camping / cell reselection to another base station even if there is no signal transmitted from the serving base station if the current serving base station is in sleep state and thus not transmitting. Therefore, unnecessary power consumption may be prevented. In addition, unnecessary waste of resources such as PRACH (Physical Random Access Channel) and PUCCH (Physical Uplink Control Channel) can also be prevented.

[0179] - Information about NCR-Sleep-RNTI: The NCR-Sleep-RNTI may be an RNTI used to scramble a PDCCH containing an indicator / information for causing the NCR to enter a sleep state or an off state.

[0180] - Information about sleep time: When the NCR enters sleep mode, information about the sleep time during which the NCR should maintain sleep mode may be included in the RRC message.

[0181] Thereafter, the base station can transmit a PDCCH to the NCR-MT(s) (S1030). Here, the PDCCH can be scrambled based on the NCR-Sleep-RNTI. In addition, a format for controlling the NCR (e.g., DCI format 2_8, etc.) or a newly defined DCI format can be used for the PDCCH. In addition, as an example, the PDCCH can include an indicator or information that instructs the NCR receiving the PDCCH to enter a sleep state. In addition, the PDCCH can include an indicator or information that indicates a time for maintaining the sleep state. The NCR receiving the indicator or information can not perform communication via NCR-Fwd from the moment of entering the sleep state (or the moment the sleep state is activated) to the time for maintaining the sleep state.

[0182] Thereafter, a DTX / DRX operation may be performed based on the PDCCH (S1040). Here, the DTX / DRX operation may include at least one of the following operations.

[0183] (Action 1) Transition to sleep state of NCR-MT: NCR-MT may also transition / enter into sleep state according to the transition of the cell to sleep state. For example, when the cell transitions to sleep state, i.e., when cell sleep is performed, the terminal performs DRX operation, and in this case, the terminal may not monitor PDCCH, etc. during the off period. As another example, when cell sleep is performed, the terminal may not transmit PUCCH, PRACH, SR (Scheduling Request), etc. during the off period.

[0184] (Action 2) Transition to sleep state for the access link of NCR-Fwd: The access link of NCR-Fwd may transition to sleep state in the same manner as the NCR-MT transitions to sleep state. For example, according to the above-mentioned action 2, NCR-Fwd may turn off the transmit RF for the access link and may not perform transmission on the access link. As another example, NCR-Fwd may turn off the receive RF for the access link and may not perform reception on the access link.

[0185] (Action 3) Returning NCR-MT from sleep state to active state: When NCR-MT transitions from sleep state to active state, at least one of the following actions may be performed.

[0186] (Operation 3-1) Timer operation: The NCR that receives the RRC message through step S1020 can obtain information about transition to sleep mode (e.g., information about sleep time, NCR-Sleep-RNTI, etc.). Here, the NCR that receives the PDCCH through step S1030 can perform a timer operation. That is, after receiving the PDCCH, the timer of the NCR starts, and when the sleep time expires (i.e., when the timer is terminated), the NCR can transition from the sleep mode (or sleep state) to the wake-up mode (or active mode / state). In other words, the NCR that receives the RRC message through step S1020 can obtain information about transition to sleep mode, and the NCR that receives the PDCCH through step S1030 can enter the sleep mode for NCR-MT.

[0187] (Action 3-2) Adjusting Cell Reselection Priority: When the mode / state of the NCR switches from sleep to active, the NCR-MT will perform an operation to find a cell to perform repeating / reselection. At this time, the NCR-MT may adjust the cell reselection priority to preferentially reselect the cell that was in service before the sleep state in order to prevent unnecessary changes in cell topology due to the sleep state. Here, at least one of the following operations may be performed to adjust the priority.

[0188] (Action 3-2-1) Setting cell priority: When NCR-MT returns to the active state after entering the sleep state, NCR can decide which cell to reselect first, the order / priority of the cells, etc. based on the cell information stored before the sleep state (e.g., frequency information for the cell, physical cell ID (PCID), E-UTRAN Cell Global ID (ECGI), NR Cell Global ID (NCGI), etc.).

[0189] (Action 3-2-2) Temporarily prohibit reselection of other cells: When NCR-MT returns to active state after entering sleep state, NCR can decide which cell to reselect based on cell information stored before entering sleep state (e.g., frequency information for cell, physical cell ID (PCID), E-UTRAN Cell Global ID (ECGI), NR Cell Global ID (NCGI), etc.). Here, if the transition of a specific cell from sleep state to active state is relatively later than the time point of entry of NCR-MT into active state, NCR-MT will not be able to find the specific cell based on the stored cell information during cell reselection, and thus, cell reselection to another cell may be performed due to cell reselection failure. To prevent this, NCR-MT can have an additional timer, i.e., a timer for prohibiting reselection to another cell, and while the timer is running, NCR can maintain cell reselection priority for the stored cell.

[0190] FIG. 11 is a flowchart of an example of an NCR control method for network energy saving according to one embodiment of the present specification.

[0191] Referring to Fig. 11, the NCR-MT transmits capability information to the base station (S1110). Here, the capability information may be transmitted via a control link (or control link) between the NCR-MT and the base station. In addition, the capability information may include information or an indicator indicating that the entity transmitting the capability information is the NCR. In addition, the capability information may include an indicator / information indicating that the NCR has the capability to enter a sleep state and / or an indicator / information indicating that the NCR can perform a sleep operation.

[0192] The base station transmits an RRC message to the NCR-MT (S1120). Here, the RRC message may be a previously defined RRC message, such as an RRC reconfiguration message, an RRC connection-related message, or an RRC resume message, or may be a newly defined RRC message for network energy conservation. Here, the RRC message may include at least one of the following information.

[0193] - Indicator / information indicating prohibition of cell reselection for NCR sleep state: In case of NCR, it is necessary to prevent cell reselection to another serving cell for network stabilization. To this end, an indicator or information indicating prohibition of cell reselection for NCR sleep state can be defined / set. When the indicator / information is set, the terminal may not attempt camping / cell reselection to another base station even if there is no signal transmitted from the serving base station if the current serving base station is in sleep state and thus not transmitting. Therefore, unnecessary power consumption may be prevented. In addition, unnecessary waste of resources such as PRACH (Physical Random Access Channel) and PUCCH (Physical Uplink Control Channel) can also be prevented.

[0194] - Information about NCR-Sleep-RNTI: The NCR-Sleep-RNTI may be an RNTI used to scramble a PDCCH containing an indicator / information for causing the NCR to enter a sleep state or an off state.

[0195] - Information about sleep time: When the NCR enters sleep mode, information about the sleep time during which the NCR should maintain the sleep mode may be included in the RRC message.

[0196] The base station transmits a PDCCH to the NCR-MT (S1130). Here, the PDCCH may be scrambled by the C(cell)-RNTI or the NCR-Sleep-RNTI. In addition, the PDCCH may include control information for controlling the NCR.

[0197] The base station transmits a medium access control-control element (MAC-CE) to the NCR-MT (S1140). Here, the MAC-CE may be transmitted via a PDSCH. At this time, the NCR-MT may receive information for receiving the PDSCH via the PDCCH of step S1130. In addition, the MAC-CE may include information indicating the state of the NCR (e.g., the on-off state or wake-up-sleep state described above) or the transition of the NCR state.

[0198] For example, the MAC-CE may include an indicator or information that instructs the NCR receiving the MAC-CE to enter a sleep state. In addition, the MAC-CE may include an indicator or information that indicates the time for which the sleep state will be maintained. The NCR receiving the indicator or information may not perform communication via NCR-Fwd from the moment of entering the sleep state (or the moment the sleep state is activated) to the time for which the sleep state will be maintained.

[0199] The above NCR (i.e., NCR-MT and / or NCR-Fwd) performs operations related to the sleep state of the NCR (S1150). In step S1150, the NCR may perform at least one of the following operations.

[0200] (Action 1) Transition to sleep state of NCR-MT: NCR-MT may also transition / enter into sleep state according to the transition of the cell to sleep state. For example, when the cell transitions to sleep state, i.e., when cell sleep is performed, the terminal performs DRX operation, and in this case, the terminal may not monitor PDCCH, etc. during the off period. As another example, when cell sleep is performed, the terminal may not transmit PUCCH, PRACH, SR (Scheduling Request), etc. during the off period.

[0201] (Action 2) Transition to sleep state for the access link of NCR-Fwd: The access link of NCR-Fwd may transition to sleep state in the same manner as the NCR-MT transitions to sleep state. For example, according to the above-mentioned action 2, NCR-Fwd may turn off the transmit RF for the access link and may not perform transmission on the access link. As another example, NCR-Fwd may turn off the receive RF for the access link and may not perform reception on the access link.

[0202] (Action 3) Returning NCR-MT from sleep state to active state: When NCR-MT transitions from sleep state to active state, at least one of the following actions may be performed.

[0203] (Operation 3-1) Timer operation: The NCR that receives the RRC message through step S1120 can obtain information about transition to sleep mode (e.g., information about sleep time, NCR-Sleep-RNTI, etc.). Here, the NCR that receives the PDCCH through step S1130 can receive information for scheduling PDSCH. Thereafter, the NCR can receive the PDSCH and perform a timer operation based on the MAC-CE included in the PDSCH. That is, after receiving the MAC-CE, the timer of the NCR starts, and when the sleep time expires (i.e., when the timer is terminated), the NCR can transition from the sleep mode (or sleep state) to the wake-up mode (or active mode / state).

[0204] Specifically, the NCR that receives the RRC message through step S1120 can obtain information about transition to sleep mode and can receive PDCCH through step S1130. Here, the PDCCH can include information indicating MAC-CE for controlling the NCR. The NCR that receives the PDCCH can obtain the MAC-CE transmitted through the PDSCH through NCR-Fwd in step S1140. The NCR that obtains the MAC-CE can enter the sleep mode for NCR-MT.

[0205] (Action 3-2) Adjusting Cell Reselection Priority: When the mode / state of the NCR switches from sleep to active, the NCR-MT will perform an operation to find a cell to perform repeating / reselection. At this time, the NCR-MT may adjust the cell reselection priority to preferentially reselect the cell that was in service before the sleep state in order to prevent unnecessary changes in cell topology due to the sleep state. Here, at least one of the following operations may be performed to adjust the priority.

[0206] (Action 3-2-1) Setting cell priority: When NCR-MT returns to the active state after entering the sleep state, NCR can decide which cell to reselect first, the order / priority of the cells, etc. based on the cell information stored before the sleep state (e.g., frequency information for the cell, physical cell ID (PCID), E-UTRAN Cell Global ID (ECGI), NR Cell Global ID (NCGI), etc.).

[0207] (Action 3-2-2) Temporarily prohibit reselection of other cells: When NCR-MT returns to active state after entering sleep state, NCR can decide which cell to reselect based on cell information stored before entering sleep state (e.g., frequency information for cell, physical cell ID (PCID), E-UTRAN Cell Global ID (ECGI), NR Cell Global ID (NCGI), etc.). Here, if the transition of a specific cell from sleep state to active state is relatively later than the time point of entry of NCR-MT into active state, NCR-MT will not be able to find the specific cell based on the stored cell information during cell reselection, and thus, cell reselection to another cell may be performed due to cell reselection failure. To prevent this, NCR-MT can have an additional timer, i.e., a timer for prohibiting reselection to another cell, and while the timer is running, NCR can maintain cell reselection priority for the stored cell.

[0208] Meanwhile, for example, a Logical Channel Identifier (LCID) or an extended LCID (eLCID) may be used to distinguish the MAC-CE. Here, the LCID and / or eLCID may be included in the MAC header or MAC subheader and used to identify the logical channel instance of the corresponding MAC SDU (Service Data Unit) or the type of the corresponding MAC-CE. For example, an eLCID may be defined for a MAC-CE that controls the state or state transition of the NCR. The codepoint and index of the MAC-CE that controls the state or state transition of the NCR may be defined as shown in Table 5 below. However, Table 5 described below is merely an example, and the codepoint and index of the MAC-CE that controls the state or state transition of the NCR may be defined in various ways.

[0209]

[0210] Fig. 12 illustrates an example of the format of a MAC CE that controls the state or state transition of an NCR. Here, the index of the MAC CE of Fig. 12 may be a newly defined index as shown in Table 5.

[0211] Referring to Fig. 12, the MAC CE (or NCR Sleep state control MAC CE) that controls the state or state transition of the NCR that received the MAC CE may include a field indicating the time for which the sleep state is to be maintained (in this specification, the field is referred to as a sleep duration field). The sleep duration field indicates the time for which the NCR maintains the sleep state, and the unit of the time may include minutes, seconds, etc. In addition, the field indicated by R may be a reserved field.

[0212] Alternatively, a previously defined LCID or eLCID may be used for the LCID or eLCID used for the MAC-CE controlling the state or state transition of the NCR. For example, it may be considered that the NCR Access Link Beam Indication MAC CE of index 287 of Table 2 is also used for the MAC-CE controlling the state or state transition of the NCR.

[0213] FIG. 13 illustrates an example of a format of a MAC CE controlling a state or state transition of the NCR when the NCR Access Link Beam Indication MAC CE of index 287 is used for the MAC CE controlling a state or state transition of the NCR.

[0214] Referring to Fig. 13, the left side of Fig. 13 illustrates the format of the existing NCR Access Link Beam Indication MAC CE of index 287. Here, the field indicated by S on the right side of Fig. 13 is an indicator indicating entry into a sleep state of the NCR (in this specification, the indicator is named an NCR-Sleep indicator or sleep bit). The NCR receiving the MAC-CE can check the sleep bit to determine that the MAC-CE is a MAC CE (or NCR Sleep state control MAC CE) that controls the state or state transition of the NCR. In this case, the NCR can interpret the MAC-CE as in the format shown on the right side of Fig. 13. Here, the MAC CE (or NCR Sleep state control MAC CE) that controls the state or state transition of the NCR may include a field indicating a time for maintaining the sleep state (in this specification, the field is named a sleep duration field). The above sleep period field indicates the time for which the NCR remains in a sleep state, and the unit of the time may include minutes, seconds, etc.

[0215] FIG. 14 is a flowchart of an example of an operation method performed by an NCR according to one embodiment of the present specification.

[0216] Referring to Figure 14, the NCR transmits capability information to the base station (S1410). Here, the capability information may include a capability indicator indicating whether the NCR can enter a sleep state. Furthermore, the base station may be a serving base station for the NCR. Furthermore, the capability information may be transmitted via a control link between the NCR and the base station.

[0217] The NCR receives an RRC message from the base station (S1420). Here, the RRC message may be a previously defined RRC message, such as an RRC reconfiguration message, an RRC connection-related message, or an RRC resume message, or may be a newly defined RRC message for network energy conservation. Here, the RRC message may be transmitted through a control link between the NCR and the base station.

[0218] Additionally, the RRC message may include at least one of the following information:

[0219] - Indicator / information indicating prohibition of cell reselection for NCR sleep state: In case of NCR, it is necessary to prevent cell reselection to another serving cell for network stabilization. To this end, an indicator or information indicating prohibition of cell reselection for NCR sleep state can be defined / set. When the indicator / information is set, the terminal may not attempt camping / cell reselection to another base station even if there is no signal transmitted from the serving base station if the current serving base station is in sleep state and thus not transmitting. Therefore, unnecessary power consumption may be prevented. In addition, unnecessary waste of resources such as PRACH (Physical Random Access Channel) and PUCCH (Physical Uplink Control Channel) can also be prevented.

[0220] - Information about NCR-Sleep-RNTI: The NCR-Sleep-RNTI may be an RNTI used to scramble a PDCCH containing an indicator / information for causing the NCR to enter a sleep state or an off state.

[0221] - Information about sleep time: When the NCR enters sleep mode, information about the sleep time during which the NCR should maintain sleep mode may be included in the RRC message.

[0222] The NCR receives a PDCCH from the base station (S1430). Here, the PDCCH may be scrambled by C(cell)-RNTI or NCR-Sleep-RNTI. In addition, the PDCCH may include control information for controlling the NCR. In addition, the PDCCH may be transmitted through a control link between the NCR and the base station.

[0223] The NCR receives a medium access control-control element (MAC-CE) from the base station (S1440). Here, the MAC-CE may be transmitted via a PDSCH. At this time, the NCR-MT may receive information for receiving the PDSCH via a PDCCH in step S1430. In addition, the MAC-CE may include information indicating a state of the NCR (e.g., the on-off state or wake-up-sleep state described above) or a transition of the NCR state. In addition, the MAC-CE may be transmitted via a backhaul link between the NCR and the base station.

[0224] For example, the MAC-CE may include an indicator or information that instructs the NCR receiving the MAC-CE to enter a sleep state. In addition, the MAC-CE may include an indicator or information that indicates the time for which the sleep state will be maintained. The NCR receiving the indicator or information may not perform communication via NCR-Fwd from the moment of entering the sleep state (or the moment the sleep state is activated) to the time for which the sleep state will be maintained.

[0225] The above NCR (i.e., NCR-MT and / or NCR-Fwd) performs an operation related to the sleep state of the NCR (S1450). Here, the operation may include an operation that does not perform transmission and reception based on NCR-Fwd. In addition, the operation of S1450 may include at least some of the operations described through step S1150 of FIG. 11. Furthermore, the methods proposed in this specification may be combined within a range in which they are not overlapping with each other. Therefore, redundant descriptions are omitted. For example, in the case of FIG. 14, step S1440 may correspond to step S1140 of the example of FIG. 11. If, unlike FIG. 11, the example of FIG. 10 is implemented or performed, operations related to FIG. 10 may be implemented, and in this case, step S1140 may be omitted.

[0226] Figure 15 illustrates a terminal and network node implementing an embodiment of the present specification. The terminal of Figure 15 may include a user device and / or an NCR. Additionally, the network node of Figure 15 may include an NCR.

[0227] Referring to FIG. 15, the terminal (1000) includes a processor (1010), a memory (1020), and a transceiver (1030). The processor (1010) may be configured to implement the functions, processes, and / or methods described herein. Layers of the wireless interface protocol may be implemented in the processor (1010).

[0228] The memory (1020) is connected to the processor (1010) and stores various information for driving the processor (1010). The transceiver (1030) is connected to the processor (1010) and transmits a wireless signal to a network node (1050) or receives a wireless signal from the network node (1050).

[0229] The network node (1050) includes a processor (1060), a memory (1070), and a transceiver (1080). In the present embodiment, the network node (1050) is a node of a non-terrestrial network and may include an artificial satellite performing a wireless access procedure according to the present specification. Alternatively, the network node (1050) in the present embodiment may be a node of a terrestrial network and may include a base station performing a wireless access procedure according to the present specification.

[0230] The processor (1060) may be configured to implement the functions, processes, and / or methods described herein. Layers of a wireless interface protocol may be implemented in the processor (1060). A memory (1070) is connected to the processor (1060) and stores various information for driving the processor (1060). A transceiver (1080) is connected to the processor (1060) and transmits a wireless signal to the terminal (1000) or receives a wireless signal from the terminal (1000).

[0231] The processor (1010, 1060) may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. The memory (1020, 1070) may include a read-only memory (ROM), a random access memory (RAM), flash memory, a memory card, a storage medium, and / or other storage devices. The transceiver (1030, 1080) may include a baseband circuit for processing radio frequency signals. When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) that performs the above-described function. The module may be stored in the memory (1020, 1070) and executed by the processor (1010, 1060). The memory (1020, 1070) may be internal or external to the processor (1010, 1060) and may be connected to the processor (1010, 1060) by various well-known means.

[0232] In the exemplary system described above, methods that can be implemented according to the features of the present invention have been described based on a flowchart. For convenience, the methods have been described as a series of steps or blocks. However, the claimed features of the present invention are not limited to the order of the steps or blocks, and some steps may occur in a different order or simultaneously with other steps than described above. Furthermore, those skilled in the art will understand that the steps depicted in the flowchart are not exclusive, and other steps may be included, or one or more steps in the flowchart may be deleted without affecting the scope of the present invention.

[0233] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined to implement a device, and the technical features of the device claims of this specification may be combined to implement a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined to implement a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined to implement a method. Furthermore, the embodiments set forth in this specification may be combined as long as they are not mutually incompatible.

Claims

1. A method performed by a network-controlled repeater (NCR) in a wireless communication system, Transmit capability information to a base station, wherein the capability information includes a capability indicator indicating whether the NCR can enter a sleep state; Receive configuration information from the base station, wherein the configuration information includes information related to discontinuous transmission / discontinuous reception (DTX / DRX) operation for the NCR, Receive downlink control information (DCI) from the base station, and Perform the DTX / DRX operation based on the above DCI, A method characterized in that the above DTX / DRX operation does not perform at least one of transmission and reception by the NCR.

2. In paragraph 1, Transmission and reception by the above NCR include transmission and reception for the access link of the above NCR, A method characterized in that the above access link is a link between the NCR and a terminal connected to the NCR.

3. In paragraph 1, A method characterized in that the above DTX / DRX related information includes at least one of information instructing the NCR to prohibit cell reselection while performing the DTX / DRX operation and information on an RNTI (Radio Network Temporary Identifier) ​​for scrambling a PDCCH (Physical Downlink Control Channel) through which the DCI is transmitted.

4. In paragraph 1, The above setting information is transmitted via RRC (Radio Resource Control) messages, The above DCI includes information instructing the NCR to perform the DTX / DRX operation, A method characterized in that the above capability information is transmitted through a control link between the NCR and the base station.

5. In paragraph 1, The above DTX / DRX operation includes a timer operation, A method characterized in that the timer operation includes an operation in which, after receiving the DCI, the NCR starts a timer, while the timer is operating, the NCR does not perform at least one of transmission and reception by the NCR, and when the timer expires, the NCR resumes at least one of transmission and reception by the NCR.

6. In paragraph 1, A method characterized in that the DCI includes information about the duration of the DTX / DRX operation.

7. In paragraph 1, A method characterized in that the step of performing the DTX / DRX operation based on the DCI includes the step of receiving a medium access control-control element (MAC-CE) based on the DCI and the step of performing the DTX / DRX operation based on the MAC-CE.

8. In paragraph 7, A method characterized in that the above MAC-CE is transmitted through a PDSCH (Physical Downlink Shared Channel).

9. In paragraph 7, A method characterized in that the DCI includes information for scheduling the PDSCH.

10. In paragraph 7, The above DTX / DRX operation includes a timer operation, A method characterized in that the timer operation includes an operation in which, after receiving the MAC-CE, the NCR starts a timer, while the timer is operating, the NCR does not perform at least one of transmission and reception by the NCR, and when the timer expires, the NCR resumes at least one of transmission and reception by the NCR.

11. Network-controlled repeater (NCR) One or more memories that store instructions; one or more transmitters and receivers; and One or more processors connecting the one or more memories and the one or more transceivers, wherein the one or more processors execute the instructions, Transmit capability information to a base station, wherein the capability information includes a capability indicator indicating whether the NCR can enter a sleep state; Receive configuration information from the base station, wherein the configuration information includes information related to discontinuous transmission / discontinuous reception (DTX / DRX) operation for the NCR, Receive downlink control information (DCI) from the base station, and Perform the DTX / DRX operation based on the above DCI, An NCR characterized in that the above DTX / DRX operation does not perform at least one of transmission and reception by the NCR.

12. In paragraph 11, Transmission and reception by the above NCR include transmission and reception for the access link of the above NCR, An NCR characterized in that the above access link is a link between the NCR and a terminal connected to the NCR.

13. In paragraph 11, An NCR characterized in that the above DTX / DRX related information includes at least one of information for instructing the NCR to prohibit cell reselection while performing the DTX / DRX operation and information for an RNTI (Radio Network Temporary Identifier) ​​for scrambling a PDCCH (Physical Downlink Control Channel) through which the DCI is transmitted.

14. In paragraph 11, The above setting information is transmitted via RRC (Radio Resource Control) messages, The above DCI includes information instructing the NCR to perform the DTX / DRX operation, An NCR characterized in that the above capability information is transmitted through a control link between the NCR and the base station.

15. In paragraph 11, The above DTX / DRX operation includes a timer operation, An NCR characterized in that the timer operation includes an operation in which, after receiving the DCI, the NCR starts a timer, while the timer is operating, the NCR does not perform at least one of transmission and reception by the NCR, and when the timer expires, the NCR resumes at least one of transmission and reception by the NCR.

16. In paragraph 11, NCR characterized in that the DCI includes information on the duration of the DTX / DRX operation.

17. In paragraph 11, An NCR characterized in that the step of performing the DTX / DRX operation based on the DCI includes the step of receiving a medium access control-control element (MAC-CE) based on the DCI and the step of performing the DTX / DRX operation based on the MAC-CE.

18. In paragraph 17, NCR characterized in that the above MAC-CE is transmitted through PDSCH (Physical Downlink Shared Channel).

19. In paragraph 17, NCR, characterized in that the DCI includes information for scheduling the PDSCH.

20. In paragraph 17, The above DTX / DRX operation includes a timer operation, An NCR characterized in that the timer operation includes an operation in which, after receiving the MAC-CE, the NCR starts a timer, while the timer is operating, the NCR does not perform at least one of transmission and reception by the NCR, and when the timer expires, the NCR resumes at least one of transmission and reception by the NCR.

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