Method and apparatus for performing cell reselection for cell supporting wake-up radio in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a terminal in a wireless communication system comprises: a step of receiving, from a base station, wake-up signaling (WUS) resource configuration information for WUS; a step in which a terminal in an idle or inactive state transmits the WUS to the base station on the basis of the WUS resource configuration information; and a step of receiving a signal for cell reselection from the base station.

Description

Method and device for performing cell reselection for a cell supporting wake-up radio in a wireless communication system

[0001] The present disclosure relates to operations of terminals and base stations in wireless communication systems. More specifically, in a Network Energy Saving (NES) system supporting power saving technology, when a base station or a cell's transceiver terminal enters sleep mode, the present disclosure relates to a cell reselection procedure of a terminal for reselecting a base station or cell in sleep mode, and a method and device for transmitting and receiving signals.

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

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

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

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

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

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

[0008] Meanwhile, in a non-terrestrial network system, methods and devices for supporting mobility using location information of terminals have been proposed, and for terminals that can utilize these, the need for a mobility support method that utilizes relative location measurement between the terminal and the network, which is different from the existing signal strength-based method, has emerged.

[0009] The present disclosure provides a method and device for improving handover performance of a terminal by utilizing power saving mode operation information of a network in a wireless communication system.

[0010] The present disclosure proposes a method and device for transmitting wake up signaling (WUS) for the purpose of cell reselection in a terminal of a wireless communication system.

[0011] The present disclosure proposes a method and device for cell reselection based on a low power synchronization signal block (LP-SSB) and a general synchronization signal block (SSB).

[0012] The technical problems to be achieved in the embodiments of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0013] According to one embodiment of the present disclosure, a method performed by a terminal in a wireless communication system is proposed. More specifically, the method comprises the steps of: receiving, from a base station, WUS resource configuration information for wake-up signaling; transmitting, by a terminal in an idle or inactive state, a WUS to the base station based on the WUS resource configuration information; and receiving, from the base station, a signal for cell reselection.

[0014] According to another embodiment of the present disclosure, a method performed by a terminal in a wireless communication system is proposed. More specifically, the method comprises the steps of: receiving a low power synchronization signal block (LP-SSB) from a first base station; receiving an SSB from a second base station; and reselecting a cell based on the LP-SSB received from the first base station and the SSB received from the second base station.

[0015] According to another embodiment of the present disclosure, a method performed by a base station in a wireless communication system is proposed. More specifically, the method comprises the steps of: transmitting wake-up signaling (WUS) resource configuration information for WUS to a terminal; acquiring WUS from a terminal in an idle or inactive state based on the WUS resource configuration information; and transmitting a signal for cell reselection to the terminal.

[0016] According to another embodiment of the present disclosure, a terminal in a wireless communication system is proposed. More specifically, the terminal includes a transceiver for transmitting and receiving signals; and a control unit, wherein the control unit receives, from a base station, WUS resource configuration information for wake-up signaling (WUS), and, based on the WUS resource configuration information, causes a terminal in an idle or inactive state to transmit a WUS to the base station, and receives a signal for cell reselection from the base station.

[0017] According to another embodiment of the present disclosure, a terminal in a wireless communication system is proposed. More specifically, the terminal includes a transceiver for transmitting and receiving signals; and a control unit, wherein the control unit receives a low power synchronization signal block (LP-SSB) from a first base station, receives an SSB from a second base station, and reselects a cell based on the LP-SSB received from the first base station and the SSB received from the second base station.

[0018] According to another embodiment of the present disclosure, a base station in a wireless communication system is proposed. More specifically, the base station includes a transceiver for transmitting and receiving signals; and a control unit, wherein the control unit is characterized in that it transmits wake-up signaling (WUS) resource configuration information for WUS to a terminal, acquires WUS from a terminal in an idle or inactive state based on the WUS resource configuration information, and transmits a signal for cell reselection to the terminal.

[0019] A method for a terminal to perform a conditional handover by utilizing power saving mode operation information of a network according to an embodiment of the present disclosure may include an operation in which a first base station sets a handover condition for a conditional handover to the terminal according to power saving mode operations of adjacent base stations including the first base station, an operation in which the terminal determines power saving mode state information of adjacent base stations including the first base station, an event in which the terminal determines an event based on the information, for example, an adjacent base station to which the terminal will trigger a handover, and an operation in which the handover is performed to the adjacent base station when the condition of the event is satisfied.

[0020] According to one embodiment of the present disclosure, in a wireless communication system, handover of a terminal can be performed more quickly by effectively utilizing information on the network's power saving mode operation.

[0021] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0022] FIG. 1 is a diagram illustrating the structure of a new radio (NR) system according to one embodiment of the present disclosure.

[0023] FIG. 2 is a diagram for explaining the network energy saving (NES) mode concept of a base station or cell according to one embodiment of the present disclosure.

[0024] FIG. 3 is a diagram illustrating a procedure for transmitting and receiving a wake up signal (WUS) signal between a terminal and a base station according to one embodiment of the present disclosure.

[0025] FIG. 4 is a diagram illustrating a procedure in which a terminal and a base station transmit and receive a wake up signal (WUS) signal according to another embodiment of the present disclosure.

[0026] FIG. 5 is a diagram illustrating a procedure for a terminal and a base station to transmit and receive a wake up signal (WUS) signal according to another embodiment of the present disclosure.

[0027] FIG. 6 is a diagram illustrating a procedure for transmitting and receiving a wake up signal (WUS) signal between a terminal and a base station according to another embodiment of the present disclosure.

[0028] FIG. 7 is a diagram illustrating a procedure in which a terminal receives different synchronization system blocks (SSBs) and selects a cell in an environment in which Deep Sleep Cells and Awake Cells (MR On) coexist according to one embodiment of the present disclosure. (Cell Selection using different SSBs)

[0029] FIG. 8 is a diagram illustrating a modified radio resource management (RRM) measurement model to which various offsets can be applied, according to one embodiment of the present disclosure.

[0030] FIG. 9 is a diagram illustrating a procedure for a terminal to perform a cell reselection procedure according to an embodiment of the present disclosure.

[0031] FIG. 10 is a diagram illustrating a procedure for a terminal to report terminal capability information according to an embodiment of the present disclosure.

[0032] FIG. 11 is a diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0033] FIG. 12 is a diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

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

[0035] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, and terms referring to various identification information are provided for convenience of explanation. Therefore, the present invention is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0036] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included in a system to which the embodiments of the present disclosure may be applied, and 5G below may also be a concept that includes existing LTE, LTE-A, and other similar services. Furthermore, the present disclosure may be applied to other communication systems with some modifications, as determined by a person skilled in the art, without significantly departing from the scope of the present disclosure. It will be appreciated that each block of the processing flow diagrams and combinations of the flow diagrams can be executed by computer program instructions.

[0037] These computer program instructions may be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, so that the instructions executed by the processor of the computer or other programmable data processing apparatus create means for performing the functions described in the flowchart block(s). These computer program instructions may also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing apparatus to implement functions in a particular manner, so that the instructions stored in the computer-available or computer-readable memory can produce an article of manufacture that includes instruction means for performing the functions described in the flowchart block(s). The computer program instructions may also be installed on a computer or other programmable data processing apparatus, so that a series of operational steps are performed on the computer or other programmable data processing apparatus to create a computer-implemented process, so that the instructions executing on the computer or other programmable data processing apparatus can provide steps for performing the functions described in the flowchart block(s).

[0038] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order depending on the corresponding function. In this case, the term '~unit' used in the present embodiment means software or a hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the '~unit' may perform certain roles. However, the '~unit' is not limited to software or hardware. The '~unit' may be configured to be on an addressable storage medium and may be configured to execute one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~ units' may be implemented to reproduce one or more CPUs within a device or a secure multimedia card. Also, in an embodiment, the '~ unit' may include one or more processors.

[0039] For convenience of explanation, this disclosure uses terms and names defined in the 5GS and NR standards, which are standards defined by the 3rd Generation Partnership Project (3GPP). However, the present invention is not limited to these terms and names and can be equally applied to wireless communication networks that comply with other standards. For example, the present invention can be applied to the 3GPP 5GS / NR (5th generation mobile communication standard).

[0040] NES-WUR based cell selection / reselection

[0041] In order to evaluate adjacent cells other than the serving cell for the purpose of cell reselection, the terminal can calculate the Srxlev value and the Squal value using the variable values ​​received from the serving cell, and determine whether they meet the cell selection criterion received from the serving cell.

[0042] When a terminal is in the RRC Idle or RRC Inactive state, it can determine and select a suitable cell. Among the suitable cells selected in this manner, the terminal can camp on the cell with the highest priority.

[0043] A terminal camping on a cell must periodically check for a better cell based on cell reselection criteria. If a better cell is found, the terminal can select that cell.

[0044] Cell selection procedure:

[0045] The cell selection procedure can be one of the following two procedures:

[0046] a) Initial cell selection (when there is no prior information about the frequency and channel usage system)

[0047] A. The terminal scans all radio frequency (RF) channels within the available system frequency band to find a suitable cell.

[0048] B. For each frequency, the terminal only needs to find the strongest cell. Exceptionally, when using shared spectrum channel access, the terminal may sequentially search for the strongest cell(s).

[0049] C. If a suitable cell is found, that cell is selected.

[0050] b) Cell selection using prior information

[0051] A. Pre-stored information on frequencies is required. Optionally, information on cell parameters contained in previously received measurement control information elements or information on previously detected cells may also be included.

[0052] B. If a suitable cell is found, that cell is selected.

[0053] C. If no suitable cell is found, the cell selection procedure of a) is initiated.

[0054] Priorities between frequencies provided as system information broadcast to the terminal or dedicated signaling, or priorities between Radio Access Technology (RAT) are not used in the cell selection procedure.

[0055] The cell selection condition S is satisfied when the following conditions are met:

[0056] Srxlev > 0 AND Squal > 0

[0057] Here:

[0058] Srxlev = Q rxlevmeas - (Qrxlevmin + Q rxlevminoffset )- P compensation - Qoffset NESWUR - Qoffset temp

[0059] Squal = Q qualmeas - (Q qualmin + Q qualminoffset ) - Qoffset NESWUR - Qoffset temp

[0060] where:

[0061]

[0062] The new offset value above is Qoffset NESWUR is operating in Deep Sleep mode and may be an offset applicable to NES WUR operating cells transmitting LP-SSB.

[0063] The new offset value above is Qoffset NESWUR may be an offset applicable to LP-SSB transmitted to any WUR.

[0064] The signalled values ​​Q rxlevminoffset and Q qualminoffset are only applied when a cell is evaluated for cell selection as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN (TS 23.122 [9]). During this periodic search for higher priority PLMN, the UE may check the S criteria of a cell using parameter values ​​stored from a different cell of this higher priority PLMN.

[0065] Cell reselection procedure:

[0066] The cell reselection procedure is as follows [Table 1]:

[0067] [Table 1]

[0068]

[0069] The terminal can perform cell reselection evaluation only for frequencies included in the system information and frequencies for which priority has been provided.

[0070] [Table 2]

[0071]

[0072] The measurement rules for cell reselection are to ensure that the terminal performs only the measurements that are absolutely necessary, and are as follows [Table 3]:

[0073] [Table 3]

[0074]

[0075] If the serving cell is a NES-WUR cell and reselection is performed via a WUR signal, the following parameters can be applied, and in this case, the procedure is as follows [Table 4]:

[0076] [Table 4]

[0077]

[0078]

[0079] In order to compare cell quality and select a good cell during cell selection and reselection, the terminal can measure each cell to determine its ranking. - Variation B: Introduce NES-WUR cell or frequency specific offset for cell ranking criterion R

[0080] - It can be broadcasted or dedicated signaled

[0081] The cell ranking criterion Rs for the serving cell and the cell ranking criterion Rn for the adjacent cell are defined as follows:

[0082] R s = Q meas,s +Q hyst - Qoffset NESWUR - Qoffset temp

[0083] R n = Q meas,n -Qoffset - Qoffset NESWUR - Qoffset temp

[0084] where:

[0085]

[0086] The terminal ranks cells that satisfy the cell selection criterion S.

[0087] The cell is Q as stated above meas,n Value and Q meas,s The average RSRP value is used to calculate the R value, and the ranking is determined accordingly.

[0088] If rangeToBestCell is not set, the terminal performs cell reselection to the cell with the highest rank.

[0089] If rangeToBestCell is set, the terminal performs cell reselection among the cells whose R value is within the rangeToBestCell difference from the R value of the highest-ranked cell, and the cell with the largest number of beams exceeding the threshold (ieabsThreshSS-BlocksConsolidation).

[0090] In all cases, the terminal performs reselection to a new cell only when the following conditions are satisfied:

[0091] - Treselection at regular intervals RATWhen a new cell is better than the current serving cell according to the cell reselection criteria specified above.

[0092] - When at least 1 second has passed since the terminal camped on the current serving cell.

[0093] If rangeToBestCell is set for a frequency but absThreshSS-BlocksConsolidation is not set, the terminal assumes that there is one beam that exceeds the threshold for each cell in that frequency band.

[0094] FIG. 1 is a diagram illustrating the structure of a new radio (NR) system according to one embodiment of the present disclosure.

[0095] Referring to Figure 1, the wireless access network of the NR system may be composed of a next-generation base station (g Node B, hereinafter referred to as gNB, Node B or base station) and a CN (Core Network). User equipment (UE) or terminals may access an external network through the gNB and CN.

[0096] In Figure 1, the gNB corresponds to the existing Node B of the UMTS system or the existing Enhanced Node B (ENB) of the LTE system. The gNB is connected to the UE via a wireless channel and can perform a more complex role than the existing ENB. In the NR system, all user traffic, including real-time services such as VoIP (Voice over IP) via the Internet Protocol, is serviced through a shared channel. Therefore, a device that collects status information such as the buffer status of the UEs, the available transmission power status, and the channel status and performs scheduling is required, and this is handled by the gNB. A single gNB typically controls multiple cells. For example, to implement a transmission rate of 100 Mbps, the NR system uses, for example, orthogonal frequency division multiplexing (OFDM) as a radio access technology in a 20 MHz bandwidth. In addition, the adaptive modulation and coding (AMC) method is applied, which determines the modulation scheme and channel coding rate according to the channel status of the UE.

[0097] The NR CN can perform functions such as mobility support, bearer setup, and quality of service (QoS) settings. The CN is a device that handles various control functions as well as mobility management for terminals and can be connected to multiple base stations. Furthermore, the next-generation mobile communication system can be interoperable with the existing LTE system, and the CN can be connected to the mobility management entity (MME) via a network interface. The MME can also be connected to existing base stations, such as eNBs.

[0098] FIG. 2 is a diagram for explaining the network energy saving (NES) mode concept of a base station or cell according to one embodiment of the present disclosure.

[0099] Referring to FIG. 2, a base station supporting a Wake Up Radio (WUR) function may be referred to as a WUR BS, and a terminal supporting the Wake Up Radio (WUR) function may be referred to as a WUR UE. The WUR BS may include a Main Radio (MR) for performing wireless communication with a WUR UE and a WUR for performing a Wake Up operation, and the WUR UE may include a Main Radio (MR) for performing wireless communication with the WUR BS and a WUR for performing a Wake Up operation. In this case, the MR of the WUR BS may perform wireless communication with the MR of the WUR UE or other UE, and the WUR of the WUR BS may perform wireless communication with the WUR of the WUR UE.

[0100] According to one embodiment of the present disclosure, the WUR may be a single but logically distinct module, rather than two physically different modules as part of the MR.

[0101] According to one embodiment of the present disclosure, the WUR may be a part of the MR, both physically and logically.

[0102] WUR BS and WUR UE can have the following operational configuration states.

[0103] 1. Full On state with both MR and WUR turned on

[0104] 2. MR On state where only MR is on and WUR is off

[0105] 3. Deep Sleep state where MR is off and only WUR is on

[0106] 4. Full Off state with both MR and WUR turned off

[0107] FIG. 3 is a diagram illustrating a procedure for transmitting and receiving a wake up signal (WUS) signal between a terminal and a base station according to an embodiment of the present disclosure.

[0108] More specifically, FIG. 3 illustrates a procedure in which a terminal transmits a Wake Up Signal (WUS) signal to a base station according to an embodiment of the present disclosure, and the base station, upon receiving the signal, wakes up from sleep mode. (WUS Basics)

[0109] Hereinafter, the terminal may include a Main Radio (MR) and a wake up radio user equipment (WUR UE), and the base station may include a Main Radio (MR) and a wake up radio base station (WUR BS) as a gNB.

[0110] Referring to FIG. 3, in step 310, a WUR UE (terminal, 301) can transmit a Wake Up Signal (WUS) to a WUR BS (base station, gNB, 302) operating in a Deep Sleep state, and the WUR BS (302) can receive the WUS. At this time, the WUS can be received through the WUR receiver of the WUR BS.

[0111] In step 320, the base station (302) that received the WUS can wake up from the Deep Sleep state and transition to the MR On state or the Full On state.

[0112] According to one embodiment of the present disclosure, the WUR may be a single but logically distinct module, rather than two physically different modules as part of the MR.

[0113] According to one embodiment of the present disclosure, the WUR may be a part of the MR, both physically and logically.

[0114] FIG. 4 is a diagram illustrating a procedure in which a terminal and a base station transmit and receive a wake up signal (WUS) signal according to another embodiment of the present disclosure.

[0115] More specifically, FIG. 4 illustrates a procedure in which a terminal transmits a Wake Up Signal (WUS) signal based on information received from a base station according to an embodiment of the present disclosure, and the base station receiving the WUS signal wakes up from sleep mode. (WUS info Basics)

[0116] Hereinafter, the terminal may include a Main Radio (MR) and a wake up radio user equipment (WUR UE), and the base station may include a Main Radio (MR) and a wake up radio base station (WUR BS) as a gNB.

[0117] Referring to FIG. 4, in step 410, the base station (402) may be configured to transmit a signal to the terminal (401) to enable transmission of WUS. For example, the signal may mean WUS information. More specifically, the base station (402) may transmit a signal containing all or part of the following WUS resource information to the terminal (401).

[0118] - Any resource information such as time / frequency at which WUS can be transmitted,

[0119] ■ For example, resource information including subframe / raioframe / slot time information that has some rule that repeats periodically.

[0120] ■ For example, resource information including WUS transmission time duration as absolute time, number of slots, number of frames, etc.

[0121] ■ For example, resource information including the interval until the start time, such as absolute time, number of slots, number of frames, timer, etc., to indicate a start time that can be transmitted after a certain period of time after receiving the signal.

[0122] ■ For example, resource information including the id of a frequency band that refers to a certain frequency band.

[0123] ■ Resource information including, for example, the ID of the resource block indicating a starting frequency, the bandwidth indicating the frequency bandwidth, the number of unit resource block frequency bandwidths, etc.

[0124] ■ For example, resource information including the ID of the reference frequency to indicate the starting frequency from a certain reference frequency, the bandwidth indicating the difference between the reference frequency and the starting frequency, the number of unit resource block frequency bandwidths, etc.

[0125] - A sequence ID or list of sequence IDs that can specify sequences that can be transmitted to WUS.

[0126] - An ID of information or a list of information IDs that indicate the type of information that can be transmitted to WUS.

[0127] - A list of condition IDs or condition IDs that indicate the type of condition that can transmit WUS.

[0128] - An indication that the terminal can transmit WUS when the base station is operating in Deep Sleep mode.

[0129] - The above information may be information about the base station transmitting the signal.

[0130] - The above information may be information of a base station (or cell) adjacent to the base station transmitting the signal, and in this case, may include a base station ID or cell ID or a base station ID list or cell ID list.

[0131] - The above information may be applied to one or more base stations or cells, and may include a list of base station IDs or cell IDs that can use the corresponding WUS transmission information.

[0132] - The above information may be applied equally to all adjacent base stations or cells (cell common information), in which case it may include an indicator (e.g., 1 bit indication) that notifies the terminal of the relevant information.

[0133] - The above information may have a structure and format similar to or identical to PRACH (Physical Random Access Channel) configuration information.

[0134] The above signal may be included in a broadcast signal transmitted by the base station to the terminal, for example, a master information block (MIB) included in an SSB, or in any system information block (SIB).

[0135] Alternatively, the signal may be transmitted by being included in a unicast signal transmitted by the base station to a specific terminal, such as a radio resource control (RRC) signal, a medium access control (MAC) signal, or a PHY signal.

[0136] In step 420, the WUR UE (terminal, 401) can transmit a Wake Up Signal (WUS) to the WUR BS (base station, gNB, 402) operating in a Deep Sleep state, and the WUR BS can receive the WUS. At this time, the WUS can be received through the WUR receiver of the WUR BS (402).

[0137] In step 430, the base station (402) that receives the WUS can wake up from the Deep Sleep state and transition to the MR On state or the Full On state.

[0138] According to one embodiment of the present disclosure, the WUR may be a single but logically distinct module, rather than two physically different modules as part of the MR.

[0139] According to one embodiment of the present disclosure, the WUR may be a part of the MR, both physically and logically.

[0140] In the above scenarios, the terminal may be an idle terminal operating in IDLE / Inactive mode. Alternatively, the terminal may be a terminal connected to another gNB and operating in Connected mode.

[0141] In the case of a terminal operating in Connected mode, the WUS info may be received from the gNB to which the terminal is connected through a broadcast signal (e.g., MIB, SIB) or a Unicast signal (e.g., RRC signal, MAC-CE, PHY signal) and used to transmit the WUS to another adjacent base station.

[0142] FIG. 5 is a diagram illustrating a procedure for a terminal and a base station to transmit and receive a wake up signal (WUS) signal according to another embodiment of the present disclosure.

[0143] More specifically, FIG. 5 illustrates a procedure in which a base station sets a Wake Up Signal (WUS) signal to a terminal according to an embodiment of the present disclosure, the terminal transmits the Wake Up Signal (WUS) signal to the base station, and the base station, upon receiving the WUS signal, wakes up from sleep mode and then transmits a synchronization signal block (SSB) to the terminal (WUS to wake-up cells to receive SSBs).

[0144] Hereinafter, the terminal may include a Main Radio (MR) and a wake up radio user equipment (WUR UE), and the base station may include a Main Radio (MR) and a wake up radio base station (WUR BS) as a gNB.

[0145] Referring to FIG. 5, in step 510, the base station (502) can set WUS resource information for transmitting WUS to the terminal (501).

[0146] The above WUS resource information may be transmitted by the base station (502) to the MR. In this case, the base station sets the WUS resource information to the terminal when the MR is turned on, and can receive the WUS transmitted by the terminal with the corresponding WUS resource when the MR is turned off. The WUS resource information may also be transmitted by the base station to the WUR.

[0147] The above WUS resource information may include all or part of the WUS resource information described above in FIG. 4. The WUS resource information may be transmitted through unicast transmission, such as a radio resource control (RRC) message or a medium access control (MAC) message. Alternatively, it may be transmitted through broadcast transmission, such as a master information block (MIB) or a system information block (SIB).

[0148] The above WUS resource information may include an indicator indicating a WUS transmission condition that causes the terminal to transmit a WUS when it wants to receive information and signals of the corresponding base station, for example, a Synchronization Signal, MIB, or SIB.

[0149] In step 520, the WUR UE (terminal, 501) can transmit a Wake Up Signal (WUS) to the WUR BSs (base stations, gNBM, 502) operating in a Deep Sleep state, and the WUR BSs can receive the WUS. At this time, the WUS can be received through the WUR receiver of the WUR BS.

[0150] In step 530, the base station (502) that received the WUS can wake up from the Deep Sleep state and transition to the MR On state or the Full On state.

[0151] In step 540, base stations that have woken up from the Deep Sleep state and have their MR turned on can transmit SSBs via MRs. According to one embodiment of the present disclosure, various signals for cell reselection can be used instead of the SSB. Various signals for cell reselection can include a system information block (SIB) (e.g., SIB1).

[0152] A terminal receiving SSB can perform random access by selecting the optimal base station and / or cell.

[0153] Afterwards, the terminal can connect to the cell according to the random access procedure and perform wireless data communication.

[0154] According to one embodiment of the present disclosure, the WUR may be a single but logically distinct module, rather than two physically different modules as part of the MR.

[0155] According to one embodiment of the present disclosure, the WUR may be a part of the MR, both physically and logically.

[0156] FIG. 6 is a diagram illustrating a procedure for transmitting and receiving a wake up signal (WUS) signal between a terminal and a base station according to another embodiment of the present disclosure.

[0157] More specifically, FIG. 6 illustrates a procedure in which a serving base station sets a Wake Up Signal (WUS) signal to a terminal according to an embodiment of the present disclosure, the terminal transmits the Wake Up Signal (WUS) signal to another neighboring base station, and the base station that receives the WUS wakes up from sleep mode and then transmits an SSB to the terminal. (WUS for neighbor gNB)

[0158] Hereinafter, the terminal may include a Main Radio (MR) and a wake up radio user equipment (WUR UE), and the base station may include a Main Radio (MR) and a wake up radio base station (WUR BS) as a gNB.

[0159] Referring to FIG. 6, in step 610, the serving base station (602) can set WUS resource information for transmitting WUS to the terminal (601).

[0160] The above WUS resource information may be transmitted by the serving base station (602) to the MR. The above WUS resource information may be transmitted by the serving base station (602) to the WUR. The above WUS resource information may include all or part of the WUS resource information described above in FIG. 4.

[0161] The above WUS resource information may be transmitted as a unicast transmission, such as a radio resource control (RRC) message or a medium access control (MAC) message. Alternatively, it may be transmitted as a broadcast transmission, such as a master information block (MIB) or a system information block (SIB).

[0162] The above WUS resource information may include an indicator indicating a WUS transmission condition that causes the terminal to transmit a WUS when it wants to receive information and signals of the corresponding base station, for example, a Synchronization Signal, MIB, or SIB.

[0163] In step 620, the WUR UE (terminal) can transmit a Wake Up Signal (WUS) to neighboring WUR BSs (base stations, 603) operating in a Deep Sleep state, and the neighboring WUR BSs can receive the WUS. At this time, the WUS can be received through the WUR receiver of the WUR BS.

[0164] In step 630, the adjacent base station (603) that received the WUS can wake up from the Deep Sleep state and transition to the MR On state or the Full On state.

[0165] In step 640, base stations that have woken up from the Deep Sleep state and have their MR turned on can transmit SSBs via MRs. According to one embodiment of the present disclosure, various signals for cell reselection can be used instead of the SSB. Various signals for cell reselection can include a system information block (SIB) (e.g., SIB1).

[0166] A terminal receiving SSB can perform random access by selecting the optimal base station and / or cell.

[0167] Afterwards, the terminal can connect to the cell according to the random access procedure and perform wireless data communication.

[0168] According to one embodiment of the present disclosure, the WUR may be a single but logically distinct module, rather than two physically different modules as part of the MR.

[0169] According to one embodiment of the present disclosure, the WUR may be a part of the MR, both physically and logically.

[0170] FIG. 7 is a diagram illustrating a procedure in which a terminal receives different synchronization system blocks (SSBs) and selects a cell in an environment in which Deep Sleep Cells and Awake Cells (MR On) coexist according to one embodiment of the present disclosure. (Cell Selection using different SSBs)

[0171] Hereinafter, the terminal may include a Main Radio (MR) and a wake up radio user equipment (WUR UE), and the base station may include a Main Radio (MR) and a wake up radio base station (WUR BS) as a gNB.

[0172] Referring to FIG. 7, in step 710, the terminal (701) can receive different types of synchronization signals or reference signals from gNB1 (702) operating in Deep Sleep mode and gNB2 (703) operating in Awake mode (or normal mode).

[0173] Here, the signal transmitted by gNB1 (702) operating in Deep Sleep mode may be a low-power synchronization signal, not a general synchronization signal, and a low-power synchronization system block (SSB) including a master information block (MIB) and / or a system information block (SIB), or a low power synchronization system block (LP-SSB). According to one embodiment of the present disclosure, a low-power signal for cell reselection may be used instead of the LP-SSB.

[0174] A terminal (701) that receives different types of synchronization signals, for example, LP-SSB and SSB, may perform the following procedure for equality comparison. According to one embodiment of the present disclosure, a low-power signal for cell reselection may be used instead of LP-SSB, and a signal for cell reselection may be used instead of SSB.

[0175] According to one embodiment of the present disclosure, the terminal (701) can compensate for and compare differences between different signals by adding or multiplying an offset to the received signal strength of a specific type of synchronization signal or reference signal (e.g., reference signals received power (RSRP), reference signal received quality (RSRQ), channel quality indicator (CQI), signal to noise ratio (SNR), signal to interference-plus-noise ratio (SINR), etc.).

[0176] For example, the terminal can multiply the RSRP value of LP-SSB by a certain offset-1 value and calculate the representative value of the cell that transmitted the LP-SSB using the radio resource management (RRM) measurement model.

[0177] Alternatively, for example, the terminal can add an offset-2 value to the RSRQ value of SSB and calculate a representative value of the cell that transmitted the SSB using the value through the RRM measurement model.

[0178] According to another embodiment of the present disclosure, a terminal can compensate for and compare differences between different signals by adding or multiplying an offset to a representative value of a corresponding cell calculated through an RRM measurement model according to a specific type of synchronization signal or reference signal transmitted by a cell.

[0179] For example, the terminal can multiply the RSRP value of LP-SSB by a certain offset-1 value and calculate the representative value of the cell that transmitted the LP-SSB using the RRM measurement model.

[0180] Alternatively, for example, the terminal can add an offset-2 value to the RSRQ value of SSB and calculate a representative value of the cell that transmitted the SSB using the value through the RRM measurement model.

[0181] It goes without saying that the above offset values ​​and various numerical values ​​used in the RRM measurement model may be included in the radio resource control (RRC) signal, medium access control (MAC) signal, PHY signal transmitted unicast by the base station to the terminal, or in the MIB or SIB transmitted as a broadcast.

[0182] In step 730, the terminal (701) that has compared different types of synchronization signals can perform Random Access by selecting (or reselecting) the optimal base station and / or cell.

[0183] FIG. 8 is a diagram illustrating a modified radio resource management (RRM) measurement model that can apply various offsets according to an embodiment of the present disclosure. (FIG. 8 RRM measurement model)

[0184] Referring to FIG. 8, the base station can set some or all of various offsets for various measurement values, and the terminal can derive a representative value of the cell according to the settings.

[0185] Offset 1 in Fig. 8 is an offset value that is directly multiplied or added to the reference signals received power (RSRP), reference signal received control (RSRQ), channel quality indicator (CQI), signal to noise ratio (SINR), signal to interference-plus-noise ratio (SNR), etc., which are the measurement values ​​of each reference signal or synchronization signal measured by the terminal, before L1 filtering.

[0186] Offset 2 in Fig. 8 is an offset value that is multiplied or added to the value derived after L1 filtering the measured values ​​of each reference signal or synchronization signal measured by the terminal, such as RSRP, RSRQ, CQI, SINR, and SNR.

[0187] Offset 3 in Fig. 8 is an offset value that is multiplied or added to the representative value of the cell derived through beam consolidation and selection (for example, taking the average of the measurement values ​​of the N best beams among beams having a signal strength higher than a threshold set by the base station) after L1 filtering the measurement values ​​of each reference signal or synchronization signal measured by the terminal, such as RSRP, RSRQ, CQI, SINR, and SNR.

[0188] Offset 4 in Fig. 8 is an offset value that is multiplied or added to the representative value of the cell derived through beam consolidation and selection (for example, taking the average of the measurement values ​​of the N best beams among beams with signal strengths higher than a threshold set by the base station) after L1 filtering the measurement values ​​of each reference signal or synchronization signal measured by the terminal, such as RSRP, RSRQ, CQI, SINR, and SNR, and then L3 filtering.

[0189] The above offset values ​​and various numerical values ​​used in the RRM measurement model may be included in a radio resource control (RRC) signal, a medium access control (MAC) signal, a PHY signal transmitted unicast by the base station to the terminal, or a master information block (MIB) or system information block (SIB) transmitted as a broadcast.

[0190] The offset values ​​and the process of applying the offset values ​​within the above RRM measurement model may be partially omitted. It goes without saying that the offset values ​​may not be set, or may be set to 1, so as not to have any influence on the process of deriving the cell representative value of the terminal.

[0191] The above offset values ​​can be calculated using any formula using all or part of the components below.

[0192] - Bandwidths, Tx powers, Frequencies, Pathlosses of the signal (LP-SSB, SSB, LP-CSI-RS, CSI-RS, …)

[0193] FIG. 9 is a diagram illustrating a procedure for a terminal to perform a cell reselection procedure according to an embodiment of the present disclosure.

[0194] Referring to Fig. 9, when a terminal performs cell selection (or reselection), a method for determining frequency priority for base stations in Deep Sleep mode may be as follows. (frequency priority handling when some gNBs are in Deep Sleep)

[0195] Hereinafter, the terminal may include a Main Radio (MR) and a wake up radio user equipment (WUR UE), and the base station may include a Main Radio (MR) and a wake up radio base station (WUR BS) as a gNB.

[0196] At step 910, the terminal (UE, 901) may be in RRC connected mode (RRC_CONNECTED) by establishing a radio resource control (RRC) connection with a base station (gNB, 902).

[0197] In step 920, the base station (902) can transmit an RRC release message (RRCRelease message) to the terminal (901).

[0198] At this time, the terminal (901) can be set a frequency priority for determining which frequency band to perform cell reselection on first through the RRCRelease message. Thereafter, the terminal (901) can operate by applying the set frequency priority.

[0199] The above message may include a frequency-specific cell reselection priority value supporting NES-WUR and / or LP-SSB. Alternatively, the message may include an instruction to apply a frequency-specific cell reselection priority value supporting NES-WUR and / or LP-SSB broadcasted in system information. The message may include a t320 value or a new timer value associated with the instruction or the priority value. The terminal may start the timer with the corresponding value.

[0200] For reference, the frequency-specific cell reselection priority values ​​supporting NES-WUR and / or LP-SSB may be signaled as in the cell reselection procedure embodiment described above, or may be signaled as an offset to the cell reselection priority values ​​derived in the cell reselection procedure embodiment described above, such that the cell reselection priority values ​​derived in the cell reselection procedure embodiment described above plus the values ​​signaled in the present disclosure may become the final cell reselection priority values.

[0201] Thereafter, in step 930, the terminal (902) may disconnect from the serving cell or perform cell reselection after receiving the RRCRelease message. For example, if the terminal receives the RRCRelease message containing the suspension configuration information (suspendConfig), the terminal may transition to RRC inactive mode, and otherwise, transition to RRC idle mode.

[0202] At step 940, a terminal (901) in RRC idle mode or RRC deactivation mode can receive essential system information broadcast by a cell or gNB (902) via MR or WUR. In the present disclosure, the Master Information Block (MIB) and System Information Block 1 (SIB1) may be referred to as essential system information. The essential system information (MIB or SIB1) may include predetermined information applicable to a terminal supporting WUR. The predetermined information may mean at least one of the following:

[0203] - Indicator of whether to transmit Low-Power Synchronization Signal (LP-SSB) or setting information for LP-SSB

[0204] - Indicates whether to transmit a Low-Power Wake-up Signal (WUS) or configuration information for WUS.

[0205] - Q rxlevminWUR : Minimum signal reception level value required when a terminal supporting WUR selects a cell supporting NES-WUR and / or LP-SSB.

[0206] - Q qualminWUR : Minimum signal quality level value required when a terminal supporting WUR selects a cell supporting NES-WUR and / or LP-SSB.

[0207] - Q rxlevminoffsetWUR : Minimum signal reception level offset value required when a terminal supporting WUR selects a cell supporting NES-WUR and / or LP-SSB.

[0208] - Q qualminoffsetWUR : Minimum signal quality level offset value required when a terminal supporting WUR selects a cell supporting NES-WUR and / or LP-SSB.

[0209] In step 950, a terminal (901) in RRC idle mode or RRC deactivation mode can perform a cell selection procedure based on system information received in the previous step.

[0210] The above terminal can find a suitable cell belonging to the selected PLMN or SNPN and camp on the cell. The definition of a suitable cell may follow the above-described embodiment. Since a terminal supporting WUR can efficiently save power by selecting or reselecting a cell supporting WUS and / or LP-SSB, a terminal following the present disclosure can derive a cell selection reception signal level value (Srxlev) and a cell selection signal quality value (Squal) through at least one of the proposed methods below (i.e., the methods below may be combined or only one of the methods below may be performed), and if both Srxlev and Squal are greater than 0, it can be determined that a cell selection criterion is fulfilled.

[0211] - Method 1: When a terminal supporting WUR selects a cell supporting NES-WUR and / or LP-SSB, Srxlev and Squal are derived by applying the minimum signal reception level value and minimum quality level value required.

[0212] Srxlev = Q rxlevmeas - (Q rxlevminWUR + Q rxlevminoffset ) - P compensation - -Qoffset temp,

[0213] Squal = Q qualmeas - (Q qualminWUR + Q qualminoffset ) - Qoffset temp.

[0214] For reference, Q rxlevminWUR Wow Q qualminWURThe remaining parts, except for applying Q, may follow the above-described embodiment. At this time, Q rxlevminoffset , P compensation , Qoffset temp , Q qualminoffset At least one of them may not be applicable to the terminal, in which case the terminal may consider the value as 0, i.e., the terminal may not consider the parameter in Srxlev and Squal.

[0215] - Method 2: When selecting a cell supporting NES-WUR and / or LP-SSB that can be applied by a terminal supporting WUR, Srxlev and Squal are derived by applying the minimum signal reception level offset value and the minimum quality level offset value required.

[0216] (Option 1)

[0217] Srxlev = Q rxlevmeas - (Q rxlevmin + Q rxlevminoffsetWUR + Q rxlevminoffset ) - P compensation -Qoffset temp

[0218] Squal = Q qualmeas - (Q qualmin + Q qualminoffsetWUR + Q qualminoffset ) - Qoffset temp

[0219] (Option 2)

[0220] Srxlev = Q rxlevmeas - (Q rxlevmin - Q rxlevminoffsetWUR + Q rxlevminoffset ) - P compensation -Qoffset temp

[0221] Squal = Q qualmeas - (Q qualmin - Q qualminoffsetWUR + Q qualminoffset ) - Qoffset temp

[0222] For reference, Q rxlevminoffsetWUR Wow Q qualminoffsetWUR The remaining parts, except for the additional application, may follow the above-described embodiment.

[0223] The difference between the two proposed options is that they relatively control the extent to which the terminal preferentially selects cells supporting NES-WUR and / or LP-SSB. In other words, Option 1 may cause the terminal to select fewer cells supporting NES-WUR and / or LP-SSB, while Option 2 may cause the terminal to select more cells supporting NES-WUR and / or LP-SSB. Of course, Q rxlevminoffsetWUR Wow Q qualminoffsetWUR Depending on how the range of values ​​that can be signaled is defined, Option 1 and Option 2 may be expressed as one.

[0224] Q rxlevminoffset , Q rxlevminoffsetcell , QrxlevminoffsetcellSUL, P compensation , Qoffset temp , Q qualminoffset At least one of them may not be applicable to the terminal, in which case the terminal may consider the value as 0 (i.e., the parameter may not be considered in Srxlev and Squal).

[0225] Q rxlevminoffset , Q rxlevminoffsetcell , QrxlevminoffsetcellSUL, P compensation , Qoffset temp , Q qualminoffset At least one of them may not be applicable to the terminal, in which case the terminal may consider the value as 0. That is, the parameter may not be considered in Srxlev and Squal.

[0226] - Method 3: When a terminal supporting WUR selects a cell supporting NES-WUR and / or LP-SSB, the minimum signal reception level value and its offset value are applied, and the minimum quality level value and its offset value are applied to derive Srxlev and Squal.

[0227] Srxlev = Q rxlevmeas - (Q rxlevminWUR + Q rxlevminoffsetWUR + Q rxlevminoffset ) - P compensation -Qoffset temp,

[0228] Squal = Q qualmeas - (Q qualminWUR + Q qualminoffsetWUR + Q qualminoffset ) - Qoffset temp.

[0229] For reference, Q rxlevminoffsetWUR Wow Q qualminoffsetWUR Applying Option 2 proposed in Method 2 may also be applied to the above Method 3.

[0230] - Method 4: When a terminal supporting WUR selects a cell supporting NES-WUR and / or LP-SSB, the minimum signal reception level value and its offset value are required, and the minimum quality level value and its offset value are applied to derive Srxlev and Squal.

[0231] Srxlev = Q rxlevmeas - (Q rxlevminWUR + Q rxlevminoffset ) - P compensation - Qoffset NESWUR -Qoffset temp,

[0232] Squal = Q qualmeas - (Q qualminWUR + Q qualminoffset ) - Qoffset NESWUR - Qoffset temp.

[0233] - Method 5: When a terminal supporting WUR selects a cell supporting NES-WUR and / or LP-SSB, the minimum signal reception level value and its offset value are applied, and the minimum quality level value and its offset value are applied to derive Srxlev and Squal.

[0234] Srxlev = Q rxlevmeas - (Q rxlevminWUR + Q rxlevminoffsetWUR + Q rxlevminoffset ) - P compensation - Qoffset NESWUR - Qoffset temp,

[0235] Squal = Q qualmeas - (Q qualminWUR + Q qualminoffsetWUR + Q qualminoffset ) - Qoffset NESWUR - Qoffset temp.

[0236] For reference, Q rxlevminoffsetWUR Wow Q qualminoffsetWUR Applying Option 2 proposed in Method 2 may also be applied to the above Method 5.

[0237] In the above methods, the Q rxlevminoffset , Q rxlevminoffsetWUR , Q rxlevminoffsetcell , QrxlevminoffsetcellSUL, P compensation , Qoffset NESWUR , Qoffset temp , Q qualminWUR, Q qualminoffsetWUR, Q qualminoffset At least one of them may not be applicable to the terminal, in which case the terminal may consider the value as 0. That is, the parameter may not be considered in Srxlev and Squal.

[0238] The terminal can select a cell by deriving Srxlev and Squal through MR (i.e., a signal / message transmitted by the base station through MR) or WUR (i.e., LP-SSB or WUS transmitted by the base station through WUR). Alternatively, the terminal can determine whether the cell selection criteria are met based on the aforementioned embodiment through MR, and then additionally determine whether the cell selection criteria are met through the method proposed in the present disclosure through WUR to select a cell.

[0239] In step 960, a terminal (901) in an RRC idle mode or an RRC deactivation mode can obtain system information (e.g., SIB2, SIB3, SIB4, SIB5, SIBx) containing cell reselection information from a serving cell to perform a cell reselection evaluation procedure.

[0240] In the present disclosure, the system information may include certain information applicable to a terminal supporting WUR. The certain information may mean at least one of the following:

[0241] - Frequency-specific cell reselection priority values ​​supporting NES-WUR and / or LP-SSB

[0242] ■ The above value may be signaled as in the above-described embodiment, or may be signaled as an offset to the cell reselection priority value derived in the above-described embodiment, so that the cell reselection priority value derived in the above-described embodiment plus the value signaled in the present disclosure may become the final cell reselection priority value.

[0243] - Q rxlevminLP : Minimum signal reception level value required when a terminal supporting WUR reselects a cell supporting NES-WUR and / or LP-SSB.

[0244] ■ The above values ​​can be signaled by frequency.

[0245] - QqualminLP : Minimum signal quality level value required when a terminal supporting WUR reselects a cell supporting NES-WUR and / or LP-SSB.

[0246] ■ The above values ​​can be signaled by frequency.

[0247] - Q rxlevminoffsetLP : Minimum signal reception level offset value required when a terminal supporting WUR reselects a cell supporting NES-WUR and / or LP-SSB.

[0248] ■ The above value can be signaled for each cell within each frequency, and at this time, a physical cell identifier (Physical Cell Id, PhyCellId) representing the cell can be signaled.

[0249] - Q qualminoffsetLP : Minimum signal quality level offset value required when a terminal supporting WUR selects a cell supporting NES-WUR and / or LP-SSB.

[0250] ■ The above value can be signaled for each cell within each frequency, and at this time, a physical cell identifier (Physical Cell Id, PhyCellId) representing the cell can be signaled.

[0251] - List of acceptable cells for terminals supporting NES-WUR and / or LP-SSB by frequency

[0252] ■ The above terminal can consider only the cells included in the above list as candidate cells for cell reselection.

[0253] - List of cells that terminals supporting NES-WUR and / or LP-SSB by frequency must exclude

[0254] ■ The above terminal may not consider the cells included in the above list as candidate cells for cell reselection.

[0255] - QoffsetWUR value for each neighboring cell supporting NES-WUR and / or LP-SSB in the frequency to which the serving cell belongs (intra-frequency).

[0256] ■ The above QoffsetWUR value is an offset between the serving cell and the surrounding cells within the frequency to which the serving cell belongs. The above value is used when deriving Rank (Mathematical Formula 2) in the above-described embodiment, and can be applied in at least one of the following ways.

[0257] ◆ Method 1: Rn = Qmeas,n - Qoffset - QoffsetWUR- Qoffsettemp

[0258] ◆ Method 2: Rn = Qmeas,n - QoffsetWUR- Qoffsettemp

[0259] - QoffsetWUR value for each neighboring cell supporting NES-WUR and / or LP-SSB on a different frequency (inter-frequency) than the serving cell.

[0260] ■ The above QoffsetWUR value is an offset between the serving cell and a neighboring cell within a different NR frequency from the serving cell. The above value is used when deriving the Rank in the above-described embodiment, and can be applied in at least one of the following ways.

[0261] ◆ Method 1: Rn = Qmeas,n - Qoffset - QoffsetWUR- Qoffsettemp where Qoffset = Qoffset s,n + Qoffset frequency , if Qoffset s,n is valid, otherwise this equals to Qoffset frequency

[0262] ◆ Method 2: Rn = Qmeas,n - Qoffset frequency - QoffsetWUR- Qoffsettemp

[0263] ◆ Method 3: Rn = Qmeas,n - QoffsetWUR- Qoffsettemp

[0264] In step 970, the terminal (901) in the RRC idle mode or RRC deactivation mode may perform a cell reselection evaluation process. The cell reselection evaluation process may refer to a series of processes for determining reselection priorities (reselection priorities handling), performing frequency measurement by applying measurement rules for cell reselection according to the determined reselection priorities, and evaluating cell reselection criteria accordingly to reselect a cell.

[0265] The terminal (901) according to the present disclosure can determine cell reselection priority through at least one of the methods proposed below. That is, the terminal may perform a combination of the following methods or may perform only one method.

[0266] - Method 1: If the received RRC connection release message includes a frequency-specific cell reselection priority value that supports NES-WUR and / or LP-SSB, the terminal may apply it to determine the cell reselection priority. If the terminal is running a T320 timer value or a new timer, the terminal may perform the above operation until the timer expires or is stopped. That is, the terminal may not apply the cell reselection priority value broadcasted in the system information.

[0267] - Method 2: If the T320 timer value or new timer value driven by the terminal expires or is stopped, or if the frequency-specific cell reselection priority value supporting NES-WUR and / or LP-SSB is not set, the terminal may determine the cell reselection priority by applying the frequency-specific cell reselection priority value supporting NES-WUR and / or LP-SSB broadcasted in the system information. In this case, the terminal may determine the cell reselection priority by applying only the frequency-specific cell reselection priority values ​​supporting NES-WUR and / or LP-SSB. Of course, if the terminal does not have a cell reselection priority value for NES-WUR and / or LP-SSB by frequency, it may determine the cell reselection priority by applying the cell reselection priority value described in the above-described embodiment (i.e., if there is a cell reselection priority value for NES-WUR and / or LP-SSB for a specific frequency, apply it, otherwise apply the cell reselection priority value described in the above-described embodiment).

[0268] - Method 3: If an instruction to apply a frequency-specific cell reselection priority value supporting NES-WUR and / or LP-SSB broadcasted in the system information is received, the terminal may determine the cell reselection priority by applying the frequency-specific cell reselection priority value supporting NES-WUR and / or LP-SSB broadcasted in the system information. At this time, the terminal may determine the cell reselection priority by applying only the frequency-specific cell reselection priority values ​​supporting NES-WUR and / or LP-SSB. Of course, if there is no frequency-specific cell reselection priority value for NES-WUR and / or LP-SSB, the terminal may determine the cell reselection priority by applying the cell reselection priority value described in the above-described embodiment. That is, if there is a cell reselection priority value for NES-WUR and / or LP-SSB for a specific frequency, it may be applied, and otherwise, the cell reselection priority value described in the above-described embodiment may be applied. Note that the above operation can be performed when the T320 timer or a new timer is running. Of course, the above operation can also be performed independently of the timer.

[0269] The above terminal may perform frequency measurement for cell reselection. This may follow at least one of the embodiments described above.

[0270] The terminal may determine to reselect a cell that satisfies cell reselection criteria based on the measurement value. This may follow the embodiment described above. The terminal according to the present disclosure may derive the signal reception level value (Srxlev) and the signal quality value (Squal) of a neighboring cell by applying the received system information according to the proposed method described above. The terminal according to the present disclosure may derive the Rank for each cell according to the method proposed in the embodiment described above.

[0271] In step 980, the terminal (901) receives system information (e.g., MIB or SIB1) broadcast from the candidate target cell before finally reselecting the candidate target cell, and determines based on the received system information whether the cell selection reception signal level value (Srxlev) and the cell selection signal quality value (Squal) of the candidate target cell are both greater than 0 (i.e., the cell selection criterion is satisfied (Srxlev > 0 AND Squal > 0). If the cell selection criterion is satisfied and the candidate target cell is suitable, the terminal can reselect the candidate target cell.

[0272] When the terminal (901) performs cell selection (or reselection), the method for determining frequency priority may be as follows.

[0273] First, if the terminal (901) supports NES-WUR operation and / or is camped on a cell capable of operating with NES-WUR, the terminal (901) can consider the frequency to which the serving cell belongs as the frequency with the highest priority.

[0274] Alternatively, the terminal (901) may receive a list of frequencies supporting NES-WUR from the base station, and if the list of frequencies supporting NES-WUR is received, the terminal (901) may perform cell reselection using the corresponding frequencies. If the terminal (901) cannot find a suitable cell in the frequencies supporting NES-WUR or cannot find a better cell than the serving cell, the terminal may try to find a suitable cell in the frequencies that do not support NES-WUR.

[0275] Alternatively, the terminal (901) may receive a list of frequencies that do not support NES-WUR from the base station, and when the list of frequencies that do not support NES-WUR is received, the terminal may perform cell reselection on frequencies excluding the frequencies, i.e., on frequencies that support NES-WUR. Thereafter, if the terminal (901) cannot find a suitable cell on the frequencies that support NES-WUR or cannot find a better cell than the serving cell, the terminal may try to find a suitable cell on the frequencies that do not support NES-WUR.

[0276] The terminal may receive a signal including a list of frequencies supporting NES-WUR from a serving cell. The signal may be an RRC signal (e.g., an RRC Release signal), or any MAC signal including MAC-CE, or a PHY signal such as downlink control information (DCI).

[0277] The terminal may receive a signal including an indicator, for example, a 1-bit indicator, for performing cell reselection by giving priority to frequencies supporting NES-WUR from a serving cell. The signal may be an RRC signal (for example, an RRC Release signal), or any MAC signal including MAC-CE, or a PHY signal such as DCI.

[0278] The parameters set by the terminal to perform cell selection (or reselection) may be as shown in [Table 5] to [Table 7] below.

[0279] [Table 5]

[0280]

[0281] [Table 6]

[0282]

[0283] [Table 7]

[0284]

[0285] The above [Table 5] to [Table 7] are examples of RRCRelease messages, but the embodiments of the present invention are not limited thereto. For example, a list of frequencies supporting NES-WUR, a list of frequencies not supporting NES-WUR, or an instruction to perform cell reselection with priority on frequencies supporting NES-WUR can be received through any MAC signal including MAC-CE, or a PHY signal such as downlink control information (DCI).

[0286] ◇ Introduce allowed and / or excluded NES-WUR cell list per frequency.

[0287] - To re-select the cell supporting NES-WUR.

[0288] - UE re-selects best or highest ranked cell among allowed NES-WUR cell list (or not within excluded NES-WUR cell list) on the concerned frequency(ies)

[0289] - It can be broadcast signaling or dedicated signaling.

[0290] FIG. 10 is a diagram illustrating a procedure for a terminal to report terminal capability information according to an embodiment of the present disclosure.

[0291] Figure 10 illustrates a procedure for a terminal to report terminal capability information during cell selection (or reselection) to a base station in Deep Sleep mode (frequency priority handling when some gNBs are in Deep Sleep).

[0292] Hereinafter, the terminal may include a Main Radio (MR) and a wake up radio user equipment (WUR UE), and the base station may include a Main Radio (MR) and a wake up radio base station (WUR BS) as a gNB.

[0293] Referring to FIG. 10, in step 1010, a terminal (UE, 1001) may transmit a terminal capability information message to a base station (gNB, 1002). The message may report, through an indicator or the like, that the terminal has the capability to support network energy saving wake-up signaling (NES-WUR). (Introduce NES-WUR capable UE)

[0294] According to one embodiment of the present disclosure, the terminal capability information message may include information or an indicator of whether the terminal supports network energy saving wake up radio (NES-WUR) and / or NES-WUR. (Add the capability of UE that the UE supports NES-WUR, and / or NES-WUR)

[0295] According to another embodiment of the present disclosure, the UE capability information message may include information or an indicator related to whether the UE can transmit WUS to the network and / or wake up a sleeping cell. (Add the capability of the UE that the UE can transmit WUS to the network and wake up a sleeping cell.)

[0296] According to another embodiment of the present disclosure, the UE capability information message may include information or an indicator regarding whether the UE can camp on an NES-WUR cell that is in a deep sleep mode. (Add the capability of the UE that the UE can camp on an NES-WUR cell that could be in a deep sleep mode.)

[0297] According to another embodiment of the present disclosure, the terminal capability information message may include information or an indicator as to whether the terminal can perform a modified cell reselection procedure as it supports NES-WUR.

[0298] According to another embodiment of the present disclosure, the UE capability information message may include information or an indicator regarding whether the UE can receive a low power synchronization system block (LP-SSB) from a NES-WUR cell for various purposes. (Add the capability of UE that the UE can receive LP-SSB from NES-WUR cell for various purposes) The various purposes may include at least one of synchronization, radio resource management (RRM), camping, cell selection (or re-selection), mobility (handover), beam management, and beam failure recovery.

[0299] The base station (1002) that receives the above terminal capability information can perform the above-described series of procedures based on the above terminal capability information. For example, the base station can transmit WUS information based on the terminal capability information, and can set WUS resource information for transmitting WUS. Alternatively, the base station (1002) can transmit a synchronization signal and / or a reference signal.

[0300] FIG. 11 is a diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0301] Referring to FIG. 11, the base station may include a transceiver (1110), a control unit (1120), and a storage unit (1130). The transceiver (1110), the control unit (1120), and the storage unit (1130) may operate according to the communication method of the base station described above. In addition, the network device may also correspond to the structure of the base station. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. For example, the base station may include a transceiver and a control unit. In addition, the transceiver, the control unit, and the storage unit may be implemented in the form of a single chip.

[0302] The transceiver (1110) is a general term for the receiver and transmitter of the base station, and can transmit and receive signals with terminals, other base stations, or other network devices. At this time, the transmitted and received signals may include control information and data. For example, the transceiver (1110) can transmit system information to the terminal, and can transmit a synchronization signal or a reference signal. To this end, the transceiver (1110) may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and the RF receiver.

[0303] The above-described transceiver (1110) may include a wired or wireless transceiver, and may include various configurations for transmitting and receiving signals. In addition, the transceiver (1110) may receive a signal through a communication channel (e.g., a wireless channel) and output it to the control unit (1120), and transmit the signal output from the control unit (1120) through the communication channel. In addition, the transceiver (1110) may receive a communication signal and output it to the processor, and transmit the signal output from the processor to a terminal, another base station, or another entity through a wired or wireless network.

[0304] The storage unit (1130) can store programs and data required for the operation of the base station. In addition, the storage unit (1130) can store control information or data included in a signal acquired from the base station. The storage unit (1120) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, the storage unit (1120) can store at least one of information transmitted and received through the transceiver unit (1110) and information generated through the control unit (1120).

[0305] In the present disclosure, the control unit (1120) may be defined as a circuit or application-specific integrated circuit, or at least one processor. The processor may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs. The control unit (1120) may control the overall operation of the base station according to the embodiment proposed in the present disclosure. For example, the control unit (1120) may control the signal flow between each block to perform operations according to the flowchart described above.

[0306] FIG. 12 is a diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0307] Referring to FIG. 12, the terminal may include a transceiver (1210), a terminal control unit (1220), and a storage unit (1230). The transceiver (1210), the control unit (1220), and the storage unit (1230) may operate according to the communication method of the terminal described above. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the components described above. For example, the terminal may include a transceiver and a control unit. In addition, the transceiver, the control unit, and the storage unit may be implemented in the form of a single chip.

[0308] The transceiver (1210) is a general term for the receiver and transmitter of a terminal, and can transmit and receive signals with a base station, another terminal, or a network entity. The signals transmitted and received with the base station may include control information and data. For example, the transceiver (1210) may receive system information from the base station and may receive a synchronization signal or a reference signal. To this end, the transceiver (1210) may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts the received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver. In addition, the transceiver may include a wired or wireless transceiver, and may include various configurations for transmitting and receiving signals. In addition, the transceiver can receive a signal through a wireless channel and output it to the control unit (1220), and transmit the signal output from the control unit (1220) through the wireless channel. In addition, the transceiver can receive a communication signal and output it to the processor, and transmit the signal output from the processor to a network entity through a wired or wireless network.

[0309] The storage unit (1230) can store programs and data necessary for the operation of the terminal. In addition, the memory can store control information or data included in signals obtained from the terminal. The storage unit (1230) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD.

[0310] In the present disclosure, the control unit (1220) may be defined as a circuit or application-specific integrated circuit, or at least one processor. The processor may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs. The control unit (1220) may control the overall operation of the terminal according to the embodiment proposed in the present disclosure. For example, the control unit (1220) may control the signal flow between each block to perform operations according to the flowchart described above.

[0311] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0312] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present invention.

[0313] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0314] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present invention via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present invention.

[0315] In the specific embodiments of the present disclosure described above, components included in the invention are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present invention is not limited to singular or plural components. Even components expressed in the plural form may be composed of singular elements, or even components expressed in the singular form may be composed of plural elements.

[0316] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. A method performed by a terminal in a wireless communication system, A step of receiving, from a base station, WUS resource setting information for wake up signaling (WUS); A step of transmitting WUS to the base station by a terminal in an idle or inactive state based on the above WUS resource setting information; and A method characterized by comprising the step of receiving a signal for cell reselection from the base station.

2. In paragraph 1, A method characterized in that the signal for the above cell reselection includes at least one of a system information block (SIB) or a synchronization signal block (SSB).

3. In a method performed by a terminal in a wireless communication system, A step of receiving a low power - synchronization signal block (LP-SSB) from a first base station; A step of receiving SSB from a second base station; and A method characterized by comprising a step of reselecting a cell based on the LP-SSB received from the first base station and the SSB received from the second base station.

4. In paragraph 3, A method characterized by applying different offset values ​​between the LP-SSB received from the first base station and the SSB received from the second base station.

5. In paragraph 3, A method further comprising the step of obtaining a radio resource control (RRC) release message including cell reselection priority information related to the LP-SSB.

6. In paragraph 3, A method characterized in that the first base station is in deep sleep mode and the second base station is in awake mode or normal mode.

7. A method performed by a base station in a wireless communication system, A step of transmitting WUS resource configuration information for wake up signaling (WUS) to a terminal; A step of acquiring WUS from a terminal in an idle or inactive state based on the above WUS resource setting information; and A method characterized by comprising a step of transmitting a signal for cell reselection to the terminal.

8. In paragraph 7, A method characterized in that the signal for the above cell reselection includes at least one of a system information block (SIB) or a synchronization signal block (SIB).

9. In a terminal in a wireless communication system, A transceiver for transmitting and receiving signals; and A control unit is included, wherein the control unit comprises: Receive WUS resource configuration information for wake up signaling (WUS) from the base station, Based on the above WUS resource setting information, a terminal in an idle or inactive state transmits a WUS to the base station. A terminal characterized by receiving a signal for cell reselection from the above base station.

10. In paragraph 9, A terminal characterized in that the signal for cell reselection includes at least one of a system information block (SIB) or a synchronization signal block (SSB).

11. In a terminal in a wireless communication system, A transceiver for transmitting and receiving signals; and A control unit is included, wherein the control unit comprises: From the first base station, a low power synchronization signal block (LP-SSB) is received, From the second base station, SSB is received, A terminal characterized in that a cell is reselected based on the LP-SSB received from the first base station and the SSB received from the second base station.

12. In paragraph 11, Applying different offset values ​​between the LP-SSB received from the first base station and the SSB received from the second base station, A terminal characterized in that the first base station is in deep sleep mode and the second base station is in awake mode or normal mode.

13. In paragraph 11, the control unit, A terminal characterized by obtaining a radio resource control (RRC) release message including cell reselection priority information related to the above LP-SSB.

14. In a base station in a wireless communication system, A transceiver for transmitting and receiving signals; and A control unit is included, wherein the control unit comprises: Transmits WUS resource configuration information for wake up signaling (WUS) to the terminal, Based on the above WUS resource setting information, WUS is acquired from a terminal in an idle or inactive state. A base station characterized by transmitting a signal for cell reselection to the above terminal.

15. In paragraph 14, A base station, characterized in that the signal for cell reselection includes at least one of a system information block (SIB) or a synchronization signal block (SIB).

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