WO2024172627A1 - Procédé et dispositif de détection d'une défaillance de faisceau dans un système de communication sans fil - Google Patents

Procédé et dispositif de détection d'une défaillance de faisceau dans un système de communication sans fil Download PDF

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Publication number
WO2024172627A1
WO2024172627A1 PCT/KR2024/095350 KR2024095350W WO2024172627A1 WO 2024172627 A1 WO2024172627 A1 WO 2024172627A1 KR 2024095350 W KR2024095350 W KR 2024095350W WO 2024172627 A1 WO2024172627 A1 WO 2024172627A1
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WIPO (PCT)
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bfd
base station
beam failure
bfr
configuration information
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PCT/KR2024/095350
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English (en)
Korean (ko)
Inventor
이영대
김선욱
강지원
양석철
명세창
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엘지전자 주식회사
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Publication of WO2024172627A1 publication Critical patent/WO2024172627A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/08—Testing, supervising or monitoring using real traffic
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/20—Control channels or signalling for resource management
    • H04W72/23—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal
    • H04W72/231—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal the control data signalling from the layers above the physical layer, e.g. RRC or MAC-CE signalling
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/20—Control channels or signalling for resource management
    • H04W72/23—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal
    • H04W72/232—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal the control data signalling from the physical layer, e.g. DCI signalling

Definitions

  • the present disclosure relates to a wireless communication system, and more particularly, to a method and device for beam failure detection in a wireless communication system.
  • Mobile communication systems were developed to provide voice services while ensuring user activity.
  • mobile communication systems have expanded their scope to include data services as well as voice, and currently, due to the explosive increase in traffic, resource shortages are occurring and users are demanding higher-speed services, so more advanced mobile communication systems are required.
  • next generation mobile communication system The requirements for the next generation mobile communication system are that it should be able to accommodate explosive data traffic, dramatically increase the data rate per user, accommodate a greatly increased number of connected devices, support very low end-to-end latency, and support high energy efficiency.
  • various technologies are being studied, including dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, and device networking.
  • the technical problem of the present disclosure is to provide a method and device for beam failure detection in a wireless communication system.
  • an additional technical task of the present disclosure is to provide a method and device for beam failure detection in a wireless communication system to which network energy saving (NES) is applied.
  • NES network energy saving
  • an additional technical problem of the present disclosure is to provide a method and device for recovering beam failure due to beam failure in a wireless communication system to which network energy saving (NES) is applied.
  • NES network energy saving
  • a method performed by a user equipment (UE) in a wireless communication system may include: receiving first configuration information and second configuration information from a base station, wherein the first configuration information includes information on a first beam failure detection (BFD) reference signal (RS) set, and the second configuration information includes information on one or more parameters related to BFD and/or beam failure recovery (BFR); assessing a radio link quality for the first BFD RS set; and performing uplink transmission for BFR to the base station based on detection of a beam failure for the first BFD RS set.
  • BFD beam failure detection
  • BFR beam failure recovery
  • One or more multi-antenna port RSs in the first BFD RS set may be configured, and a positive or negative offset may be applied to the one or more parameters based on some of the multi-antenna ports being turned off or having a reduced transmission power.
  • a method performed by a base station in a wireless communication system may include: transmitting first configuration information and second configuration information to a user equipment (UE), wherein the first configuration information includes information about a first beam failure detection (BFD) reference signal (RS) set, and the second configuration information includes information about one or more parameters related to BFD and/or beam failure recovery (BFR); and receiving an uplink transmission for BFR from the UE based on detection of a beam failure for the first BFD RS set according to an assessment of a radio link quality for the first BFD RS set by the UE.
  • BFD beam failure detection
  • BFR beam failure recovery
  • One or more multi-antenna port RSs in the first BFD RS set may be configured, and a positive or negative offset may be applied to the one or more parameters based on some of the multi-antenna ports being turned off or having a reduced transmission power.
  • a UE can more accurately detect beam failure by taking into account NES operation.
  • some beam resources e.g., some reference signals, some antenna ports, some antenna elements, etc.
  • some beam resources e.g., some reference signals, some antenna ports, some antenna elements, etc.
  • unnecessary declaration of beam failure of a UE can be prevented and beam failure can be detected appropriately by applying different reference signals depending on whether or not NES is operating.
  • Figure 1 illustrates the structure of a wireless communication system to which the present disclosure can be applied.
  • FIG. 2 illustrates a frame structure in a wireless communication system to which the present disclosure can be applied.
  • FIG. 3 illustrates a resource grid in a wireless communication system to which the present disclosure can be applied.
  • FIG. 4 illustrates a physical resource block in a wireless communication system to which the present disclosure can be applied.
  • FIG. 5 illustrates a slot structure in a wireless communication system to which the present disclosure can be applied.
  • FIG. 6 illustrates physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the same.
  • FIG. 7 is a diagram exemplifying a beam failure recovery operation for a P-cell in a wireless communication system to which the present disclosure can be applied.
  • FIG. 8 illustrates the configuration of a CSI-RS resource set in a wireless communication system to which the present disclosure can be applied.
  • FIG. 9 illustrates a signaling method for a beam failure detection method according to one embodiment of the present disclosure.
  • FIG. 10 is a diagram illustrating the operation of a UE for a beam failure detection method according to one embodiment of the present disclosure.
  • FIG. 11 is a diagram illustrating the operation of a base station for a beam failure detection method according to one embodiment of the present disclosure.
  • FIG. 12 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.
  • first in one embodiment
  • second component in another embodiment
  • first component in another embodiment may be referred to as a first component in another embodiment
  • the present disclosure describes a wireless communication network or a wireless communication system, and an operation performed in a wireless communication network may be performed in a process of controlling the network and transmitting or receiving a signal from a device (e.g., a base station) that manages the wireless communication network, or in a process of transmitting or receiving a signal with or between terminals connected to the wireless network.
  • a device e.g., a base station
  • transmitting or receiving a channel means transmitting or receiving information or a signal through the channel.
  • transmitting a control channel means transmitting control information or a signal through the control channel.
  • transmitting a data channel means transmitting data information or a signal through the data channel.
  • downlink means communication from a base station to a terminal
  • uplink means communication from a terminal to a base station.
  • a transmitter may be part of a base station, and a receiver may be part of a terminal.
  • a transmitter may be part of a terminal, and a receiver may be part of a base station.
  • the base station may be expressed as a first communication device, and the terminal may be expressed as a second communication device.
  • a base station may be replaced by terms such as a fixed station, a Node B, an evolved-NodeB (eNB), a Next Generation NodeB (gNB), a base transceiver system (BTS), an Access Point (AP), a network (5G network), an Artificial Intelligence (AI) system/module, a road side unit (RSU), a robot, a drone (UAV: Unmanned Aerial Vehicle), an Augmented Reality (AR) device, and a Virtual Reality (VR) device.
  • BS base station
  • eNB evolved-NodeB
  • gNB Next Generation NodeB
  • BTS Next Generation NodeB
  • AP Access Point
  • 5G network 5G network
  • AI Artificial Intelligence
  • RSU road side unit
  • robot a drone
  • UAV Unmanned Aerial Vehicle
  • AR Augmented Reality
  • VR Virtual Reality
  • the terminal may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, RSU (road side unit), robot, AI (Artificial Intelligence) module, UAV (Unmanned Aerial Vehicle), AR (Augmented Reality) device, and VR (Virtual Reality) device.
  • UE User Equipment
  • MS Mobile Station
  • UT user terminal
  • MSS Mobile Subscriber Station
  • SS Subscriber Station
  • AMS Advanced Mobile Station
  • WT Wireless terminal
  • MTC Machine-Type Communication
  • M2M Machine-to-Machine
  • D2D Device-to-Device
  • vehicle RSU (road side unit)
  • CDMA can be implemented with wireless technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000.
  • TDMA can be implemented with wireless technologies such as GSM (Global System for Mobile communications)/GPRS (General Packet Radio Service)/EDGE (Enhanced Data Rates for GSM Evolution).
  • OFDMA can be implemented with wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (Evolved UTRA).
  • Wi-Fi IEEE 802.11
  • WiMAX IEEE 802.16
  • IEEE 802-20 E-UTRA
  • Evolved UTRA Evolved UTRA.
  • UTRA is a part of UMTS (Universal Mobile Telecommunications System).
  • 3GPP(3rd Generation Partnership Project) LTE(Long Term Evolution) is a part of E-UMTS(Evolved UMTS) that uses E-UTRA
  • LTE-A(Advanced)/LTE-A pro is an evolved version of 3GPP LTE
  • 3GPP NR(New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE/LTE-A/LTE-A pro.
  • LTE refers to technology after 3GPP TS (Technical Specification) 36.xxx Release 8.
  • LTE technology after 3GPP TS 36.xxx Release 10 is referred to as LTE-A
  • LTE technology after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro
  • 3GPP NR refers to technology after TS 38.xxx Release 15.
  • LTE/NR may be referred to as a 3GPP system.
  • xxx refers to a standard document detail number.
  • LTE/NR may be collectively referred to as a 3GPP system.
  • 3GPP 3rd Generation Partnership Project
  • TS 36.211 Physical channels and modulation
  • TS 36.212 Multiplexing and channel coding
  • TS 36.213 Physical layer procedures
  • TS 36.300 General description
  • TS 36.331 Radio resource control
  • TS 38.211 Physical channels and modulation
  • TS 38.212 Multiplexing and channel coding
  • TS 38.213 Physical layer procedures for control
  • TS 38.214 Physical layer procedures for data
  • TS 38.300 Overall description of NR and New Generation-Radio Access Network (NG-RAN)
  • TS 38.331 Radio Resource Control Protocol Specification
  • Synchronization signal block including primary synchronization signal (PSS), secondary synchronization signal (SSS), and physical broadcast channel (PBCH)
  • PSS primary synchronization signal
  • SSS secondary synchronization signal
  • PBCH physical broadcast channel
  • NR is an expression indicating an example of 5G RAT.
  • the new RAT system including NR uses OFDM transmission scheme or similar transmission scheme.
  • the new RAT system may follow OFDM parameters different from those of LTE.
  • the new RAT system may follow the existing LTE/LTE-A numerology but support a larger system bandwidth (e.g., 100MHz).
  • a single cell may support multiple numerologies. That is, terminals operating with different numerologies can coexist in a single cell.
  • a numerology corresponds to one subcarrier spacing in the frequency domain.
  • Different numerologies can be defined by scaling the reference subcarrier spacing by an integer N.
  • Figure 1 illustrates the structure of a wireless communication system to which the present disclosure can be applied.
  • the NG-RAN consists of gNBs providing NG-RA (NG-Radio Access) user plane (i.e., new AS (access stratum) sublayer/PDCP (Packet Data Convergence Protocol)/RLC (Radio Link Control)/MAC/PHY) and control plane (RRC) protocol termination for UE.
  • NG-RA NG-Radio Access
  • PDCP Packet Data Convergence Protocol
  • RLC Radio Link Control
  • RRC control plane
  • the gNBs are interconnected via Xn interface.
  • the gNBs are also connected to NGC (New Generation Core) via NG interface. More specifically, the gNBs are connected to AMF (Access and Mobility Management Function) via N2 interface and to UPF (User Plane Function) via N3 interface.
  • AMF Access and Mobility Management Function
  • UPF User Plane Function
  • FIG. 2 illustrates a frame structure in a wireless communication system to which the present disclosure can be applied.
  • NR system can support multiple numerologies.
  • numerology can be defined by subcarrier spacing and cyclic prefix (CP) overhead.
  • multiple subcarrier spacing can be derived by scaling the base (reference) subcarrier spacing by an integer N (or ⁇ ). Also, even if it is assumed that very low subcarrier spacing is not used at very high carrier frequencies, the numerology used can be selected independently of the frequency band.
  • NR system can support various frame structures according to multiple numerologies.
  • OFDM numerologies and frame structures that can be considered in NR systems.
  • a number of OFDM numerologies supported in NR systems can be defined as shown in Table 1 below.
  • NR supports multiple numerologies (or subcarrier spacing (SCS)) to support various 5G services. For example, when the SCS is 15 kHz, it supports wide area in traditional cellular bands, when the SCS is 30 kHz/60 kHz, it supports dense-urban, lower latency, and wider carrier bandwidth, and when the SCS is 60 kHz or higher, it supports bandwidths greater than 24.25 GHz to overcome phase noise.
  • SCS subcarrier spacing
  • the NR frequency band is defined by two types of frequency ranges (FR1, FR2).
  • FR1 and FR2 can be configured as shown in Table 2 below.
  • FR2 can mean millimeter wave (mmW).
  • slots are numbered in increasing order of n s ⁇ ⁇ 0,..., N slot subframe, ⁇ -1 ⁇ within a subframe, and in increasing order of n s,f ⁇ ⁇ 0,..., N slot frame, ⁇ -1 ⁇ within a radio frame.
  • One slot consists of consecutive OFDM symbols of N symb slot , where N symb slot is determined according to a CP.
  • the start of slot n s ⁇ in a subframe is temporally aligned with the start of OFDM symbol n s ⁇ N symb slot in the same subframe. Not all terminals can transmit and receive simultaneously, which means that not all OFDM symbols in a downlink slot or an uplink slot can be utilized.
  • Table 3 shows the number of OFDM symbols per slot (N symb slot ), the number of slots per radio frame (N slot frame, ⁇ ), and the number of slots per subframe (N slot subframe, ⁇ ) in a general CP
  • Table 4 shows the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe in an extended CP.
  • a mini-slot can include 2, 4, or 7 symbols, or more or less symbols.
  • antenna ports With respect to physical resources in an NR system, antenna ports, resource grids, resource elements, resource blocks, carrier parts, etc. can be considered.
  • resource grids With respect to physical resources in an NR system, antenna ports, resource grids, resource elements, resource blocks, carrier parts, etc. can be considered.
  • the physical resources that can be considered in an NR system will be examined in detail.
  • an antenna port is defined such that a channel on which a symbol on an antenna port is carried can be inferred from a channel on which another symbol on the same antenna port is carried.
  • Two antenna ports are said to be in a QC/QCL (quasi co-located or quasi co-location) relationship if a large-scale property of a channel on which a symbol on one antenna port is carried can be inferred from a channel on which a symbol on another antenna port is carried.
  • the large-scale property includes one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.
  • FIG. 3 illustrates a resource grid in a wireless communication system to which the present disclosure can be applied.
  • a resource grid is exemplarily described as consisting of N RB ⁇ N sc RB subcarriers in the frequency domain and one subframe consisting of 14 ⁇ 2 ⁇ OFDM symbols, but is not limited thereto.
  • a transmitted signal is described by one or more resource grids consisting of N RB ⁇ N sc RB subcarriers and OFDM symbols of 2 ⁇ N symb ( ⁇ ) .
  • N RB ⁇ N RB max, ⁇ The N RB max, ⁇ represents a maximum transmission bandwidth, which may vary not only between numerologies but also between uplink and downlink.
  • one resource grid may be configured for ⁇ and each antenna port p.
  • Each element of the resource grid for ⁇ and each antenna port p is referred to as a resource element and is uniquely identified by an index pair (k,l').
  • l' 0,...,2 ⁇ N symb ( ⁇ ) -1 designates the position of a symbol within a subframe.
  • an index pair (k,l) is used.
  • l 0,...,N symb ⁇ -1.
  • the resource element (k,l') for ⁇ and antenna port p corresponds to a complex value a k,l' (p, ⁇ ) .
  • indices p and ⁇ can be dropped, resulting in a complex value a k,l' (p) or a k,l' .
  • Point A serves as a common reference point of the resource block grid and is obtained as follows.
  • - offsetToPointA for Primary Cell (PCell) downlink indicates the frequency offset between point A and the lowest subcarrier of the lowest resource block overlapping with the SS/PBCH block used by the UE for initial cell selection. It is expressed in resource block units assuming 15 kHz subcarrier spacing for FR1 and 60 kHz subcarrier spacing for FR2.
  • - absoluteFrequencyPointA represents the frequency-position of point A expressed as ARFCN (absolute radio-frequency channel number).
  • Common resource blocks are numbered from 0 upward in the frequency domain for the subcarrier spacing setting ⁇ .
  • the center of subcarrier 0 of common resource block 0 for the subcarrier spacing setting ⁇ coincides with 'point A'.
  • the relationship between common resource block number n CRB ⁇ in the frequency domain and resource elements (k, l) for the subcarrier spacing setting ⁇ is given by the following mathematical expression 1.
  • the physical resource blocks are numbered from 0 to N BWP,i size, ⁇ -1 within a bandwidth part (BWP), where i is the number of the BWP.
  • BWP bandwidth part
  • Equation 2 The relationship between a physical resource block n PRB and a common resource block n CRB in BWP i is given by Equation 2 below.
  • N BWP,i start, ⁇ is the common resource block where the BWP starts relative to common resource block 0.
  • FIG. 4 illustrates a physical resource block in a wireless communication system to which the present disclosure can be applied.
  • FIG. 5 illustrates a slot structure in a wireless communication system to which the present disclosure can be applied.
  • a slot includes multiple symbols in the time domain. For example, in the case of normal CP, one slot includes 7 symbols, but in the case of extended CP, one slot includes 6 symbols.
  • a carrier includes multiple subcarriers in the frequency domain.
  • An RB Resource Block
  • a BWP Bandwidth Part
  • a carrier can include up to N (e.g., 5) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for one terminal.
  • Each element in the resource grid is referred to as a Resource Element (RE), and one complex symbol can be mapped.
  • RE Resource Element
  • the NR system can support up to 400 MHz per component carrier (CC). If a terminal operating in such a wideband CC always operates with the radio frequency (RF) chip for the entire CC turned on, the terminal battery consumption may increase. Or, when considering multiple use cases (e.g., eMBB, URLLC, Mmtc, V2X, etc.) operating in a single wideband CC, different numerologies (e.g., subcarrier spacing, etc.) may be supported for each frequency band within the CC. Or, the capability for maximum bandwidth may be different for each terminal.
  • eMBB enhanced mobile broadband
  • the base station may instruct the terminal to operate in only a part of the bandwidth, not the entire bandwidth, of the wideband CC, and the part of the bandwidth is conveniently defined as the bandwidth part (BWP).
  • a BWP can be composed of consecutive RBs on the frequency axis and can correspond to one numerology (e.g., subcarrier spacing, CP length, slot/mini-slot interval).
  • the base station can set multiple BWPs even within one CC set for the terminal. For example, in the PDCCH monitoring slot, a BWP occupying a relatively small frequency range can be set, and the PDSCH indicated by the PDCCH can be scheduled on a larger BWP. Or, when UEs are concentrated in a specific BWP, some terminals can be set to different BWPs for load balancing. Or, considering frequency domain inter-cell interference cancellation between neighboring cells, some spectrum in the middle of the entire bandwidth can be excluded and both BWPs can be set within the same slot. That is, the base station can set at least one DL/UL BWP for the terminal associated with the wideband CC.
  • the base station can activate (by L1 signaling or MAC CE (Control Element) or RRC signaling, etc.) at least one DL/UL BWP among the set DL/UL BWP(s) at a specific time.
  • the base station can instruct switching to another configured DL/UL BWP (by L1 signaling or MAC CE or RRC signaling, etc.). Or, it can switch to a configured DL/UL BWP when a timer value expires based on a timer.
  • the activated DL/UL BWP is defined as an active DL/UL BWP.
  • the DL/UL BWP assumed by the UE in such a situation is defined as the initial active DL/UL BWP.
  • FIG. 6 illustrates physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the same.
  • a terminal receives information from a base station through a downlink, and the terminal transmits information to the base station through an uplink.
  • the information transmitted and received by the base station and the terminal includes data and various control information, and various physical channels exist depending on the type/purpose of the information they transmit and receive.
  • the terminal When the terminal is powered on or enters a new cell, it performs an initial cell search operation such as synchronizing with the base station (S601). To this end, the terminal can receive a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station to synchronize with the base station and obtain information such as a cell identifier (ID). Thereafter, the terminal can receive a physical broadcast channel (PBCH) from the base station to obtain broadcast information within the cell. Meanwhile, the terminal can receive a downlink reference signal (DL RS) during the initial cell search phase to check the downlink channel status.
  • PSS primary synchronization signal
  • SSS secondary synchronization signal
  • ID cell identifier
  • PBCH physical broadcast channel
  • DL RS downlink reference signal
  • a terminal that has completed initial cell search can obtain more specific system information by receiving a physical downlink control channel (PDCCH: Physical Downlink Control Channel) and a physical downlink shared channel (PDSCH: Physical Downlink Control Channel) according to information carried on the PDCCH (S602).
  • PDCCH Physical Downlink Control Channel
  • PDSCH Physical Downlink Share Channel
  • the terminal may perform a random access procedure (RACH) for the base station (steps S603 to S606).
  • RACH random access procedure
  • the terminal may transmit a specific sequence as a preamble through a physical random access channel (PRACH) (S603 and S605), and receive a response message to the preamble through a PDCCH and a corresponding PDSCH (S604 and S606).
  • PRACH physical random access channel
  • a contention resolution procedure may additionally be performed.
  • the terminal that has performed the procedure as described above can then perform PDCCH/PDSCH reception (S607) and physical uplink shared channel (PUSCH: Physical Uplink Shared Channel)/physical uplink control channel (PUCCH: Physical Uplink Control Channel) transmission (S608) as general uplink/downlink signal transmission procedures.
  • the terminal receives downlink control information (DCI: Downlink Control Information) through the PDCCH.
  • DCI Downlink Control Information
  • the DCI includes control information such as resource allocation information for the terminal, and its format is different depending on the purpose of use.
  • the control information that the terminal transmits to the base station via uplink or that the terminal receives from the base station includes downlink/uplink ACK/NACK (Acknowledgement/Non-Acknowledgement) signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indicator), etc.
  • the terminal can transmit the above-described control information such as CQI/PMI/RI via PUSCH and/or PUCCH.
  • Table 5 shows an example of DCI format in the NR system.
  • DCI formats 0_0, 0_1, and 0_2 may include resource information related to PUSCH scheduling (e.g., UL/SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), transport block (TB) related information (e.g., MCS (Modulation Coding and Scheme), NDI (New Data Indicator), RV (Redundancy Version), etc.), HARQ (Hybrid - Automatic Repeat and request) related information (e.g., process number, DAI (Downlink Assignment Index), PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), power control information (e.g., PUSCH power control, etc.), and the control information included in each DCI format may be predefined.
  • PUSCH scheduling e.g., UL/SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency
  • DCI format 0_0 is used for scheduling PUSCH in a cell.
  • Information included in DCI format 0_0 is transmitted by scrambling CRC (cyclic redundancy check) by C-RNTI (Cell RNTI: Cell Radio Network Temporary Identifier) or CS-RNTI (Configured Scheduling RNTI) or MCS-C-RNTI (Modulation Coding Scheme Cell RNTI).
  • C-RNTI Cell RNTI: Cell Radio Network Temporary Identifier
  • CS-RNTI Configured Scheduling RNTI
  • MCS-C-RNTI Modulation Coding Scheme Cell RNTI
  • DCI format 0_1 is used to indicate scheduling of one or more PUSCHs in a cell, or configure grant (CG: configure grant) downlink feedback information to the UE.
  • the information included in DCI format 0_1 is transmitted by CRC scrambled by C-RNTI or CS-RNTI or SP-CSI-RNTI (Semi-Persistent CSI RNTI) or MCS-C-RNTI.
  • DCI format 0_2 is used for scheduling PUSCH in a cell.
  • Information included in DCI format 0_2 is transmitted by CRC scrambled by C-RNTI or CS-RNTI or SP-CSI-RNTI or MCS-C-RNTI.
  • DCI formats 1_0, 1_1, and 1_2 may include resource information related to scheduling of PDSCH (e.g., frequency resource allocation, time resource allocation, virtual resource block (VRB)-physical resource block (PRB) mapping, etc.), transport block (TB) related information (e.g., MCS, NDI, RV, etc.), HARQ related information (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., antenna port, transmission configuration indicator (TCI), sounding reference signal (SRS) request, etc.), PUCCH related information (e.g., PUCCH power control, PUCCH resource indicator, etc.), and control information included in each DCI format may be predefined.
  • resource information related to scheduling of PDSCH e.g., frequency resource allocation, time resource allocation, virtual resource block (VRB)-physical resource block (PRB) mapping, etc.
  • transport block (TB) related information e.g., MCS, ND
  • DCI format 1_0 is used for scheduling PDSCH in one DL cell.
  • Information included in DCI format 1_0 is transmitted CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI.
  • DCI format 1_1 is used for scheduling PDSCH in one cell.
  • Information included in DCI format 1_1 is transmitted by CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI.
  • DCI format 1_2 is used for scheduling PDSCH in a cell.
  • Information included in DCI format 1_2 is transmitted by CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI.
  • 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 in a QC/QCL (quasi co-located or quasi co-location) relationship if the 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 another antenna port is carried.
  • QC/QCL quadsi co-located or quasi co-location
  • the channel characteristics include one or more of delay spread, Doppler spread, frequency/Doppler shift, average received power, received timing/average delay, and spatial Rx parameter.
  • the spatial Rx parameter means a spatial (reception) channel characteristic parameter such as angle of arrival.
  • the UE may be configured with a list of up to M TCI-State settings in the upper layer parameter PDSCH-Config to decode PDSCH according to the detected PDCCH having the intended DCI for the UE and the given serving cell.
  • the M depends on the UE capability.
  • Each TCI-State contains parameters for establishing a quasi co-location relationship between one or two DL reference signals and the DM-RS port of the PDSCH.
  • Quasi co-location relation is set by upper-layer parameters qcl-Type1 for the first DL RS and qcl-Type2 for the second DL RS (if set).
  • the QCL types are not the same, regardless of whether the references are the same DL RS or different DL RSs.
  • the quasi co-location type corresponding to each DL RS is given by the higher layer parameter qcl-Type of QCL-Info, and can take one of the following values:
  • the corresponding NZP CSI-RS antenna port(s) can be instructed/configured to be QCL with a specific TRS from a QCL-Type A perspective and with a specific SSB from a QCL-Type D perspective.
  • a terminal that has received such instructed/configured can receive the corresponding NZP CSI-RS using the Doppler and delay values measured at the QCL-TypeA TRS, and apply the receive beam used for QCL-TypeD SSB reception to the corresponding NZP CSI-RS reception.
  • the UE can receive an activation command by MAC CE signaling used to map up to eight TCI states to codepoints in the DCI field 'Transmission Configuration Indication'.
  • BFD Beam failure detection
  • BFR beam failure recovery
  • a beam mismatch problem may occur depending on the set beam management cycle.
  • a terminal moves, rotates, or a wireless channel environment changes due to movement of surrounding objects (for example, a LoS (line-of-sight) environment changes to a non-LOS environment due to a beam block)
  • the optimal DL/UL beam pair may change.
  • tracking fails in a beam management process generally performed by network instructions due to such a change it can be said that a beam failure event has occurred. Whether or not such a beam failure event has occurred can be determined by the terminal through the reception quality of a downlink reference signal (RS).
  • RS downlink reference signal
  • a report message for such a situation or a message for requesting beam recovery (referred to as a beam failure recovery request (BFRQ) message) must be transmitted from the terminal.
  • a base station that receives such a beam failure recovery request message can perform beam recovery through various processes such as beam RS transmission and beam reporting request for beam recovery.
  • This series of beam recovery processes is called beam failure recovery (BFR).
  • Release (Rel)-15 NR standardized the BFR (beam failure recovery) process for a primary cell (PCell: primary cell) or a primary secondary cell (PScell: primary secondary cell) (collectively called a special cell (SpCell: special cell)) where contention-based PRACH resources always exist.
  • the BFR procedure is an operation within a serving cell, and consists of the following: a beam failure detection (BFD) process of a terminal, a BFRQ process, and a process in which the terminal monitors the base station's response to the BFRQ.
  • BFD beam failure detection
  • BFRQ beam failure detection
  • FIG. 7 is a diagram exemplifying a beam failure recovery operation for a P-cell in a wireless communication system to which the present disclosure can be applied.
  • the quality is based on a hypothetical block error rate (BLER). In other words, it means the probability that demodulation of the control information will fail assuming that the control information is transmitted through the corresponding PDCCH.
  • BLER block error rate
  • one or more search spaces for monitoring PDCCH can be set for the terminal.
  • beams can be set differently for each search space. In this case, it means that all PDCCH beams for all search spaces fall below the BLER threshold.
  • BFD RS BFD reference signal
  • Implicit setting for BFD RS(s) A control resource set (CORESET) identifier (ID: identifier), which is a resource area where PDCCH can be transmitted, is set for each search space.
  • CORESET ID identifier
  • RS information e.g., CSI-RS resource ID, SSB identifier (ID)
  • QCL Quadasi Co-located
  • TCI transmit configuration information
  • the RS being QCLed e.g., QCL Type D in TS38.214
  • the base station notifies the terminal to use (or may use) the same beam that was used for receiving the spatially QCLed RS (i.e., use the same spatial domain filter for reception) when receiving the corresponding PDCCH DMRS.
  • this is a method for notifying the terminal that it will transmit by applying the same transmission beam or a similar transmission beam (e.g., when the beam direction is the same/similar but the beam width is different) between the spatially QCLed antenna ports.
  • the terminal can determine an RS that is Quasi Co-located (QCL) from the perspective of the spatial RX parameter set in the CORESET for PDCCH reception as a BFD reference signal (BFD RS) (i.e., regarded as the 'all PDCCH beams' above).
  • QCL Quasi Co-located
  • the base station can explicitly set beam reference signal(s) (beam RS(s)) to the terminal for the above purpose (beam failure detection).
  • beam RS(s) beam reference signal(s)
  • the set beam RS(s) correspond to the ‘all PDCCH beams’.
  • the terminal physical layer Whenever an event occurs where the hypothetical BLER measured based on BFD RS(s) deteriorates beyond a specific threshold, the terminal physical layer notifies the MAC sublayer that a beam failure instance (BFI) has occurred.
  • the terminal MAC sublayer determines (considers) that a beam failure has occurred if a BFI occurs a certain number of times (e.g., the value of the upper layer parameter beamFailureInstanceMaxCount) within a certain period of time (i.e., within the BFD timer) and is detected, and initiates a related RACH operation.
  • a MAC object works as follows:
  • BFI_COUNTER If the BFI counter (BFI_COUNTER) is greater than or equal to the maximum count of beam failure instances (beamFailureInstanceMaxCount):
  • the BFD timer (beamFailureDetectionTimer), the beam failure instance maximum count (beamFailureInstanceMaxCount), or any reference signals used for beam failure detection are reset by a higher layer (e.g. RRC layer):
  • stop the beam failure recovery timer (beamFailureRecoveryTimer);
  • BFRQ Beam Failure Recovery Request
  • BFD Beam Failure Detection
  • the terminal may determine that a beam failure has occurred and perform a beam failure recovery operation.
  • a beam failure recovery operation a beam failure recovery request (BFRQ) operation based on a RACH procedure (i.e., PRACH) may be performed.
  • RACH procedure i.e., PRACH
  • the base station can set an RS list (e.g., candidateBeamRSList) corresponding to candidate beams that can be replaced when a beam failure (BF) occurs to the terminal through higher layer signaling (e.g., RRC).
  • RS list e.g., candidateBeamRSList
  • dedicated PRACH resources can be set for the candidate beams.
  • the dedicated PRACH resources are non-contention based PRACH (also called contention free PRACH) resources. If the terminal cannot find an (appropriate) beam in the list, the terminal selects one of the preset SSB resources and transmits a contention based PRACH (contention based PRACH) to the base station.
  • the specific procedures are as follows.
  • Step 1) The terminal searches for a beam having a quality value (Q in ) or higher among the RSs set by the base station as a candidate beam RS set.
  • the terminal selects that beam RS.
  • the terminal randomly selects one of the beam RSs.
  • the terminal performs the following two steps.
  • beam quality can be based on RSRP.
  • the RS beam set set by the base station may include the following three cases.
  • all beam RSs in the RS beam set may be configured with SSBs.
  • all beam RSs in the RS beam set may be configured with CSI-RS resources.
  • beam RSs in the RS beam set may be configured with SSBs and CSI-RS resources.
  • Step 2 The terminal searches for a beam having a quality value (Q in ) or higher among the SSBs (connected to the contention-based PRACH resource).
  • the terminal selects the corresponding beam RS.
  • the terminal randomly selects one of the corresponding beam RSs.
  • the terminal performs the following 3 steps.
  • Step 3 The terminal selects a random SSB among the SSBs (connected with contention-based PRACH resources).
  • the terminal transmits the PRACH resource and preamble directly or indirectly connected to the beam RS (CSI-RS or SSB) selected in the above process to the base station.
  • the beam RS CSI-RS or SSB
  • PRACH resources and preambles are set up (contention-based) and mapped one-to-one with SSBs that are set up for general purposes such as random access
  • a contention-free PRACH resource and preamble are not set for a specific CSI-RS within a candidate beam RS set set separately for BFR purposes.
  • the terminal selects a (contention-free) PRACH resource and preamble associated with an SSB that is designated as being receivable in the same receive beam as the corresponding CSI-RS (i.e., QCLed (quasi-co-located with respect to the spatial Rx parameter)).
  • the terminal monitors the base station (gNB)’s response to the corresponding PRACH transmission.
  • the response to the contention-free PRACH resource and preamble is transmitted through a PDCCH masked with a C-RNTI, and the response is received in a search space (SS) separately configured by RRC for BFR.
  • SS search space
  • the search space is set to a specific CORESET (for BFR).
  • the response to a contention PRACH reuses the CORESET (e.g., CORESET 0 or CORESET 1) and search space established for the general contention PRACH based random access process.
  • CORESET e.g., CORESET 0 or CORESET 1
  • the above process can be performed until the preset maximum number of PRACH transmissions (N_max) is reached or until the configured timer (BFR timer) expires.
  • the terminal stops contention-free PRACH transmission, but contention-based PRACH transmission by SSB selection can be performed until N_max is reached.
  • the PRACH-based BFR process has been standardized in Rel-15 NR.
  • this is limited to PCell or PSCell due to technical limitations such as that some secondary cells (SCells) may not have UL carriers in CA (carrier aggregation) and that even if there is a UL carrier, contention-based PRACH cannot be set.
  • SCells secondary cells
  • CA carrier aggregation
  • contention-based PRACH cannot be set.
  • This limitation is particularly problematic when operating a PCell in a low-frequency band (e.g., below 6 GHz) while operating a high-frequency band (e.g., 30 GHz) as an SCell, as BFR cannot be supported in the high-frequency band where BFR is actually required. For this reason, standardization for BFR support for SCell is in progress in the Rel-16 NR MIMO work item.
  • (dedicated) PUCCH resource(s) will be set up to notify the base station that SCell beam failure has occurred in SpCell, and BFRQ for SCell will be performed using these.
  • the PUCCH is referred to as BFR-PUCCH hereinafter.
  • the role of BFR-PRACH standardized in Rel-15 is to transmit 'occurrence of beam failure + new beam RS (set) information' together to the base station.
  • the role of BFR-PUCCH is to only report 'occurrence of beam failure for SCell(s)'.
  • which SCell(s) has beam failure e.g., CC index(es)
  • the beam RS ID and quality(s) of the corresponding beam RS(s) (e.g., RSRP or SINR)
  • a subsequent MAC-CE or UCI.
  • the subsequent beam report does not always have to be triggered, and the base station can also deactivate the SCell(s) set to BFR for the corresponding UE after receiving the BFR-PUCCH.
  • the reason for this design is that there may be cases where dozens of SCells are connected to a single PCell/PSCell, and also, from the base station's perspective, there may be many terminals sharing a single PCell/PSCell UL. Considering these cases, it is desirable to minimize the amount of UL resources reserved for SCell BFRQ purposes for each terminal on the PCell/PSCell.
  • BFD Beam failure detection
  • the NR UE supports reception based on beamforming for downlink reception. That is, the UE receives a downlink signal using a specific beam among multiple candidate beams. In particular, when the UE is in connected mode, the base station and the UE maintain an optimal beam for the UE through a beam management (BM) process. Accordingly, the base station transmits PDCCH/PDSCH using an optimal TX beam suitable for the UE, and the UE receives PDCCH/PDSCH using an optimal RX beam.
  • BM beam management
  • REL-18 NR discusses a method for reducing power consumption of network equipment such as base stations.
  • a base station operating multiple TX and/or RX beams may communicate with UEs only through specific beam resources at specific times and not communicate with UEs through other beam resources in order to reduce power consumption of the base station.
  • the base station may deactivate some beam resources by turning them OFF for NES, and thus, the UE may have to change the RX beam selected through the BM operation due to the NES operation of the base station.
  • an optimal beam failure detection operation of a UE belonging to a cell/base station supporting NES is proposed.
  • the present disclosure proposes a method of performing BFD by applying different reference signals (RS: reference signals) depending on whether a UE attempts to connect to a base station performing network energy saving (NES) operation or is in the NES operation.
  • RS reference signals
  • the UE performs beam management (BM) related measurements (e.g., L1-RSRP/SINR) and it is up to the UE implementation whether to change the RX beam to receive the BM-RS.
  • BM beam management
  • the UE may be required to adapt the RX beam so as to optimize the base station's adaptation to the number of active antenna elements.
  • the base station may inform the UE of the CSI-RS resource (set) index to which the RX beam needs to be adapted to receive the CSI-RS resource (set), which may require processing time relaxation.
  • the base station operating in NES mode for NES may mean performing the following operations.
  • a base station can set multiple OFF intervals (discontinuous transmission intervals (DTX) of the base station), which are OFF intervals in which transmission of a specific DL signal is turned off for a specific time interval in advance.
  • the base station can dynamically instruct the UE to select one of the OFF intervals, thereby informing that the corresponding DL signal will not be transmitted for a predefined time interval, thereby reducing power consumption of the base station and the UE.
  • OFF interval is described in the time domain, but the NES operation is not limited thereto.
  • an OFF region can be set in the frequency domain through BWP switching, dynamic RB adaptation, etc. in the frequency domain.
  • the base station in the spatial domain, for example, when a specific antenna port of the base station is turned OFF semi-statically or dynamically, the base station does not transmit and/or receive a wireless signal through the corresponding antenna port, thereby reducing power consumption of the base station and the UE. It may also mean the mode of action being obtained.
  • the base station can perform the operation of NES mode for at least one domain in the time/frequency/space domain. For example, transmission and/or reception of a wireless signal can be prevented by turning OFF specific antenna port(s) in a specific period in the time domain and/or a specific frequency domain in the frequency domain and/or a specific space domain.
  • a base station can set multiple RS resource sets (e.g., CSI-RS resource sets or SSB index sets) for each UE or multiple terminals (e.g., UE groups) for BFD, and can assign a set index to each RS resource set.
  • RS resource sets e.g., CSI-RS resource sets or SSB index sets
  • UE groups e.g., UE groups
  • FIG. 8 illustrates the configuration of a CSI-RS resource set in a wireless communication system to which the present disclosure can be applied.
  • the base station can set multiple CSI-RS resources and multiple CSI-RS resource sets for the UE.
  • one CSI-RS resource set can be composed of one or more CSI-RS resources, and the same CSI-RS resource can belong to different CSI-RS resource sets (e.g., CSI-RS resource #2).
  • Example 1 BFD method according to NES
  • the UE measures the radio link quality through the DL RS that is in a QCL relationship with the PDCCH DM-RS it receives among the DL RSs determined by the q 0 set (periodic CSI-RS of a single port), and declares a beam failure if a beam failure instance (BFI) is found more than a predetermined number of times over a predetermined period of time.
  • BFI beam failure instance
  • the base station can set a plurality of RS resource sets (i.e., these can be referred to as BFD RS sets, for example, periodic CSI-RS resource sets or SSB index sets) as q 0 sets for beam failure detection (BFD).
  • BFD beam failure detection
  • the base station can set a set index for each RS resource set.
  • the UE can select one RS resource set among the plurality of RS resource sets and perform the BFD operation.
  • the base station sets multiple RS resource sets for BFD RS to the UE, and each RS resource set can be assigned a set index, and the base station can explicitly set an RS resource set to be linked for each set index.
  • the base station and the UE can activate only one set index, that is, one RS resource set, according to an explicit command/configuration of the base station or an implicit rule.
  • the UE can determine only a specific RS resource set activated by the above method as a valid BFD RS, and perform BFD using only the valid BFD RS.
  • the BFD RS can be interpreted as the BFD RS set which is the q 0 set for BFD.
  • the base station can set multiple RS resource sets for BFD RS with a higher layer message (e.g., RRC message) and instruct the UE to activate only one RS resource set through DCI or MAC control element (CE: control element) or RRC message.
  • a higher layer message e.g., RRC message
  • CE control element
  • RS resource sets #a, #b, #c, and #d can be set by an RRC message, and an RS resource set (e.g., RS resource set #b) to be initially activated or deactivated can be indicated by the RRC message.
  • RS resource set #b e.g., RS resource set #b
  • a UE that receives this RRC message can activate or deactivate the indicated RS resource set while setting the RS resource sets.
  • RS resource sets #a, #b, #c, #d can be configured by RRC message, and an RS resource set (e.g., RS resource set #b) to be activated or deactivated can be indicated via DCI or MAC CE or another RRC message.
  • the UE can configure RS resource sets #a, #b, #c, #d via RRC message, and activate or deactivate a deactivated RS resource set according to DCI or MAC CE or another RRC message.
  • the activation of a specific RS resource set can cause other RS resource sets to be deactivated.
  • the deactivation of a specific RS resource set can cause other RS resource sets to be activated.
  • all RS resource sets can be deactivated or all RS resource sets can be indicated to be activated by DCI or MAC CE or another RRC message.
  • the UE can select a BFD RS (or a set of BFD RSs (i.e., the q 0 set)) by applying the implicit configuration rules in the following way.
  • a command to activate a specific RS is not received from the base station for the corresponding cell during handover or cell addition or cell activation, or ii) if the base station instructs/configures to deactivate all RS resource sets for BFD RS set in explicit configuration, or iii) if all beam resources corresponding to RS resource sets for BFD RS set in explicit configuration are turned OFF (i.e., if all RS resources in the RS resource set are turned OFF) according to NES operation, the UE can determine that there is no valid BFD RS (or BFD RS set) in the explicit configuration.
  • the UE may determine a periodic CSI-RS (P-CSI-RS: periodic CSI-RS) having the same index as the CSI-RS linked to a TCI state configured for CORESET for PDCCH monitoring (i.e., provided by the TCI state) as a BFD RS.
  • P-CSI-RS periodic CSI-RS
  • the UE may determine an RS resource set including the periodic CSI-RS as a BFD RS set (i.e., q 0 ).
  • the base station can change the TCI state for PDCCH monitoring performed by the UE.
  • the UE can change the TCI state for PDCCH monitoring (according to the instruction of the base station), determine the RS corresponding to the changed TCI state as a BFD RS (or determine the RS resource set including the RS as a BFD RS set) to perform BFD.
  • Method 2 When there are one or more CORESETs for PDCCH monitoring, the UE may select one of the CORESETs according to a specific rule. Then, the UE may determine a P-CSI-RS having the same index as a CSI-RS linked to a TCI state configured for the selected CORESET (i.e., provided by the TCI state) as a BFD RS (or determine an RS resource set including the P-CSI-CS as a BFD RS set), or determine a P-CSI-RS that is in a QCL relationship with the TCI state configured for the selected CORESET (i.e., in a QCL relationship with the RS provided in the TCI state) as a BFD RS (or determine an RS resource set including the P-CSI-CS as a BFD RS set).
  • a P-CSI-RS having the same index as a CSI-RS linked to a TCI state configured for the selected CORESET (i.e., provided by the TCI state) as a
  • Method 2-1 The lowest (or highest) CORESET can be selected among one or more CORESETs for PDCCH monitoring.
  • a P-CSI-RS having the same index as a CSI-RS linked to a TCI state set in a specific CORESET designated by the base station or a default or pre-defined CORESET (i.e., provided by the TCI state) may be determined as a BFD RS (or an RS resource set including the P-CSI-CS may be determined as a BFD RS set), or a P-CSI-RS in a QCL relationship with the linked TCI state (i.e., in a QCL relationship with the RS provided in the TCI state) may be determined as a BFD RS (or an RS resource set including the P-CSI-CS may be determined as a BFD RS set).
  • a P-CSI-RS that is in a QCL relationship with a TCI state determined by a random access channel (RACH) procedure (i.e., a random access procedure) most recently performed by the UE (i.e., provided in the TCI state or is in a QCL relationship with a corresponding RS provided in the TCI state) may be determined as a BFD RS (or an RS resource set including a P-CSI-CS may be determined as a BFD RS set).
  • a P-CSI-RS having the same index as a CSI-RS linked to a TCI state determined by a RACH procedure most recently performed by the UE i.e., provided in the TCI state
  • BFD RS RS resource set
  • a P-CSI-RS having the same index as a CSI-RS linked to a TCI state determined by a RACH procedure most recently performed by the UE (i.e., provided in the TCI state) may be determined as a BFD RS.
  • a CSI-RS selected by a RACH procedure most recently performed may be determined as a BFD RS (or an RS resource set including a P-CSI-CS may be determined as a BFD RS set).
  • the P-CSI-RS that is in a QCL relationship with the CSI-RS selected by the UE according to the most recently executed RACH procedure may be determined as a BFD RS (or, the RS resource set including the P-CSI-CS may be determined as a BFD RS set).
  • the base station may determine the P-CSI-RS corresponding to the best ranked SSB or the SSB index higher than a threshold among the SSB beams measured by the UE as the BFD RS (or determine the RS resource set including the P-CSI-CS as the BFD RS set), or determine the P-CSI-RS in a QCL relationship with the corresponding P-CSI-RS as the BFD RS (or determine the RS resource set including the P-CSI-CS as the BFD RS set).
  • Method 5 The base station can instruct the UE whether to turn on/off a specific SSB beam or CSI-RS beam.
  • a P-CSI-RS having the same index as a CSI-RS linked to the TCI state indicated as on (i.e., provided by the TCI state) may be determined as a BFD RS (or, an RS resource set including a P-CSI-CS may be determined as a BFD RS set), or a P-CSI-RS that is in a QCL relationship with the TCI state indicated as on (i.e., in a QCL relationship with the RS provided by the TCI state) may be determined as a BFD RS (or, an RS resource set including a P-CSI-CS may be determined as a BFD RS set).
  • a P-CSI-RS linked/associated with an SSB index indicated as on may be determined as a BFD RS (or, an RS resource set including a P-CSI-CS may be determined as a BFD RS set), or a P-CSI-RS that is in a QCL relationship with an SSB index indicated as on and an SSB index indicated as on may be determined as a BFD RS (or, an RS resource set including a P-CSI-CS may be determined as a BFD RS set).
  • the UE can determine an activated RS resource set (i.e., BFD RS or BFD RS set) according to the method described above for beam failure detection, and determine the activated RS resource set as the q 0 set. Then, the following beam failure detection procedure can be performed.
  • an activated RS resource set i.e., BFD RS or BFD RS set
  • the UE may need to adjust the RX beam so that it can optimize the base station's adaptation to the number of active antenna elements. For example, the base station may inform the UE of the CSI-RS resource (set) index that the RX beam needs to be adjusted to receive the CSI-RS resource (set), which may require processing time relaxation.
  • BM related measurements e.g., L1-RSRP/SINR
  • the UE evaluates whether the downlink radio link quality for CSI-RS resources in the set q 0 estimated during the last T Evaluate_BFD_CSI-RS ms period becomes worse than a threshold Q out_LR_CSI -RS within the T Evaluate_BFD_CSI-RS ms period to detect beam failure and provide a beam failure instance (BFI) indication to higher layers (i.e., MAC).
  • BFI beam failure instance
  • the UE evaluates the downlink radio link quality of the serving cell based on the reference signals in the q 0 set to detect beam failure in:
  • the RS resource configuration in the q 0 set for a PCell, a PSCell or a disabled PSCell can be periodic CSI-RS resources and/or SSBs.
  • the RS resource configuration in the q 0 set for a SCell shall be periodic CSI-RS.
  • the UE is not required to perform beam failure detection outside the active DL BWP. If a UE does not have a q 0 set, the UE is not required to fulfill the requirements of clauses 8.5.2 and 8.5.3 of TS 38.213. The UE is not required to perform beam failure detection for disabled SCells, nor for the resources implicitly configured for the disabled SCells.
  • the UE estimates the radio link quality to access the downlink radio link quality of the serving cell beams and compares it with a threshold value Q out_LR .
  • Q out_LR_SSB is derived based on the hypothetical PDCCH transmission parameters.
  • Q out_LR_CSI-RS is derived based on the hypothetical PDCCH transmission parameters.
  • the UE Upon request, the UE forwards the L1-RSRP measurements to upper layers if the measured L1-RSRP is greater than or equal to a threshold Q in_LR as indicated by the upper layer parameter rsrp-ThresholdSSB and the configuration indices of the set q 1 as specified in TS 38.213.
  • the UE applies the Q in_LR threshold to the L1-RSRP measurements acquired from SSBs.
  • the UE applies the Q in_LR threshold to the L1-RSRP measurements acquired for the CSI-RS resources after scaling each CSI-RS receive power by the value provided by the upper layer parameter powerControlOffsetSS.
  • the RS resource configurations in the set q 1 can be periodic CSI-RS resources, SSBs, or both SSB and CSI-RS resources.
  • the UE does not need to perform candidate beam detection outside the active DL BWP.
  • the UE does not need to perform candidate beam detection on SCells where q 1 is not configured.
  • the UE may be provided with an RRC reconfiguration message with a higher layer parameter tci-info for PDCCH/PDSCH reception. After receiving the RRC reconfiguration message, the UE performs BFD on the PSCell of the deactivated SCG using the TCI state according to the higher layer parameter tci-info specified in section 6.3.2 of TS38.331.
  • the thresholds Q out,LR and Q in,LR correspond to the default value of the higher layer parameter rlmInSyncOutOfSyncThreshold for Q out and the value provided by the higher layer parameter rsrp-ThresholdSSB or the higher layer parameter rsrp-ThresholdBFR, respectively.
  • the physical layer of the UE assesses the radio link quality according to a set of resource configurations q 0 , q 0,0 or q 0,1 for threshold Q out,LR .
  • the UE assesses the radio link quality only according to the periodic CSI-RS resource configurations that are quasi co-located (QCL) with the SS/PBCH block of the PCell or PSCell or the DM-RS of the PDCCH received by the UE.
  • the UE applies the Q in,LR threshold to the L1-RSRP measurements acquired from the SS/PBCH block.
  • the UE applies the Q in,LR threshold to the L1-RSRP measurements acquired for the CSI-RS resources after scaling each CSI-RS receive power by the value provided by the higher layer parameter powerControlOffsetSS.
  • Non-DRX non discontinuous reception
  • the physical layer notifies upper layers (i.e., MAC) when the radio link quality is worse than the threshold value Q out ,LR with a periodicity determined as the shortest periodicity among SS/PBCH blocks of PCell or PSCell and/or periodic CSI-RS configurations in set q 0 , q 0,0 or q 0,1 used by the UE to estimate the radio link quality and a maximum value among 2 msec.
  • the physical layer provides an indication to upper layers when the radio link quality is worse than the threshold value Q out,LR with a periodicity determined as described in TS 38.133.
  • the base station can set different parameter values for each RS resource set for BFD.
  • the UE can perform beam failure detection by applying the corresponding values to the parameters depending on which RS resource set is valid and activated.
  • the base station can set different parameter values depending on whether it is NES mode or non-NES mode.
  • the base station can set/instruct the UE to be in NES mode or non-NES mode.
  • the UE can perform beam failure detection by applying the corresponding values to the parameters depending on whether the currently instructed or configured mode is NES mode or non-NES mode.
  • T Evaluate_BFD This refers to the period for estimating the downlink radio link quality when determining whether the radio link quality for RS resources in the set q 0 is worse than the threshold Q out_LR in order to detect beam failure and provide BFI indication to the upper layer, and corresponds to a pre-determined value based on the frequency band, whether DRX is applied, DRX cycle, etc.
  • the in-sync block error rate (BLER) i.e., BLER in
  • the out-of-sync BLER i.e., BLER out
  • the in-sync block error rate (BLER) i.e., BLER in
  • BLER out the out-of-sync BLER
  • Threshold Q in,LR It is defined as the level at which the downlink radio level link of the given resource configuration of the set q 0 can be stably received, and is a value provided by the upper layer parameter rsrp-ThresholdSSB or rsrp-ThresholdB.
  • the L1-RSRP threshold is indicated by rsrp-ThresholdSSB or rsrp-ThresholdB.
  • Upper layer parameter for SS power control offset powerControlOffsetSS Indicates the power offset of NZP CSI-RS for SSS RE in dB value.
  • rsrp-ThresholdSSB for RSRP threshold of SSB Indicates the L1-RSRP threshold used by the UE to determine whether a candidate beam can be used for attempting contention free random access to recover from beam failure.
  • Upper layer parameter rsrp-ThresholdBFR for RSRP threshold of BFR Indicates the L1-RSRP threshold used by the UE to determine whether a candidate beam can be included in the MAC CE for beam failure recovery.
  • Block error rate BLER out of hypothetical PDCCH transmission For example, it can be defined as 10%.
  • the base station can set different parameter values depending on whether specific or some antenna ports (AP: antenna ports) are turned off.
  • AP antenna ports
  • the base station can i) set/instruct the UE whether specific or some AP(s) are turned off, or ii) set/instruct the UE which AP(s) are turned off.
  • the UE can perform beam failure detection by applying the corresponding values to the parameters depending on whether specific or some APs are turned off.
  • the base station can set different parameter values depending on whether the transmission power of specific or some APs is reduced.
  • the base station can i) set/instruct the UE whether the transmission power of specific or some APs is reduced, or ii) set/instruct the UE which AP(s) has the transmission power reduced.
  • the UE can perform beam failure detection by applying the corresponding value to the parameter depending on whether the transmission power of specific or some APs is reduced.
  • the base station can notify the UE.
  • the base station can notify the UE through DCI or MAC CE or RRC message.
  • the UE can be configured to perform beam failure detection by measuring L1-RSRP while excluding the specific or some AP(s) when the AP(s) are off. On the other hand, if the AP(s) are not off, the UE can be configured to perform beam failure detection by measuring L1-RSRP without excluding the AP(s).
  • the UE may be configured to perform beam failure detection by measuring L1-RSRP while excluding the AP(s) when the transmission power of specific or some AP(s) is in a reduced state. On the other hand, if the transmission power of the AP(s) is not reduced, the UE may be configured to perform beam failure detection by measuring L1-RSRP without excluding the AP(s).
  • whether the UE performs beam failure detection by applying the value set by the base station for the one or more parameters or by applying a positive offset value or a negative offset value can be individually determined/configured for each RS resource set. For example, if a specific RS resource set is valid and activated, the UE can perform beam failure detection by applying a positive offset value or a negative offset value to the value set by the base station for the one or more parameters. On the other hand, if an RS resource set other than the specific RS resource set is valid and activated, failure detection can be performed according to the value set by the base station.
  • the UE when set or instructed to NES mode, can perform beam failure detection by applying a positive offset value or a negative offset value to the value set by the base station for one or more of the above parameters.
  • beam failure detection can be performed according to the value set by the base station.
  • the UE can perform beam failure detection by applying a positive offset value or a negative offset value to the value set by the base station for one or more parameters when some AP(s) are off. On the other hand, if some AP(s) are not off, the UE can perform beam failure detection according to the value set by the base station. Or, if the transmission power of some AP(s) is in a reduced state, the UE can perform beam failure detection by applying a positive offset value or a negative offset value to the value set by the base station for one or more parameters. On the other hand, if the transmission power of some AP(s) is not reduced, the UE can perform beam failure detection according to the value set by the base station.
  • the positive or negative offset can be set by the base station, and may be set per cell, and/or per BWP, and/or per frequency, and/or per RS for radio link failure (RLF) (e.g. per BFD RS), and/or per AP, and/or per AP group, and/or per antenna element group.
  • RLF radio link failure
  • turning on/off antenna elements of the base station may result in a change of the number of antenna elements associated with the AP for CSI-RS for L1-RSRP/SINR or the number of AP(s) for CSI-RS for L1-RSRP/SINR.
  • an approach for the CSI framework can also be applied.
  • CSI-RS resource#1 having 2 APs (or 1 AP with 32 antenna elements) and CSI-RS resource #2 having 1 AP (or 1 AP with 8 antenna elements) can be configured, and switching between CSI-RS resource#1 and CSI-RS resource #2 can be performed based on an instruction from the base station.
  • RLM/beam failure since at most 1 or 2 AP(s) are set for RLM/beam failure, for example, Q in /Q out adjustment or two candidate sets for RLM/BFD/candidate beam RS (one set with 2 APs and the other set with 1 AP).
  • the MAC layer of the UE triggers/performs the following beam failure recovery procedure.
  • the beam failure recovery procedure used by the MAC entity to indicate new SSB or CSI-RS to the serving gNB when beam failure is detected on the serving SSB(s)/CSI-RS(s) can be configured by RRC on a per serving cell or per BFD RS set basis.
  • a beam failure is detected by counting BFI indications from lower layers to the MAC entity. If the upper layer parameter BeamFailureRecoveryConfig is reset by upper layers during an ongoing random access procedure for beam failure recovery to SpCell, the MAC entity aborts the ongoing random access procedure and starts the random access procedure using the new configuration. When SCG is disabled, if the upper layer parameter bfd-and-RLM is set to 'true', the UE performs beam failure detection on the PSCell.
  • RRC sets the following parameters in BeamFailureRecoveryConfig, BeamFailureRecoverySpCellConfig, BeamFailureRecoverySCellConfig, and radioLinkMonitoringConfig for beam failure detection and recovery procedures.
  • RSRP threshold for SCell beam failure recovery or beam failure recovery of the BFD RS set of the serving cell RSRP threshold for SCell beam failure recovery or beam failure recovery of the BFD RS set of the serving cell
  • preambleReceivedTargetPower preambleReceivedTargetPower for SpCell beam failure recovery
  • preambleTransMax preambleTransMax for SpCell beam failure recovery
  • ssb-perRACH-Occasion for SpCell beam failure recovery using contention-free random access resources
  • prach-ConfigurationIndex prach-ConfigurationIndex for SpCell beam failure recovery using contention-free random access resources
  • ra-ssb-OccasionMaskIndex for SpCell beam failure recovery using contention-free random access resources
  • ra-OccasionList for SpCell beam failure recovery using contention-free random access resources
  • CandidateBeamRS-List-r16 List of candidate beams for SCell beam failure recovery or list of candidate beams for beam failure recovery of the serving cell for BFD RS set 1;
  • CandidateBeamRS-List2-r17 List of candidate beams for beam failure recovery of the serving cell for BFD RS set 2.
  • the following UE variables are used for the beam failure detection procedure.
  • BFI_COUNTER per serving cell or per BFD RS set of a serving cell configured with two BFD RS sets: Counter for BFI indications, initially set to 0.
  • the MAC entity behaves as follows for each serving cell configured for beam failure detection:
  • BFI_COUNTER BFI_COUNTER
  • the BFR procedure is considered to have been completed successfully for this BFD RS set, and all triggered BFRs for this BFD RS set of the serving cell are canceled.
  • the BFR procedure is considered to have completed successfully, and all triggered BFRs in all BFD RS sets of the serving cell are canceled.
  • BFI_COUNTER If the BFI counter (BFI_COUNTER) is greater than or equal to the maximum count of beam failure instances (beamFailureInstanceMaxCount):
  • the serving cell is an SCell and a PDCCH designated as a C-RNTI indicating an uplink grant for a new transmission is received for the HARQ process used for MAC CE transmission for BFR containing BFR information of this serving cell; or
  • the BFR procedure is considered to have completed successfully and all BFRs triggered for this serving cell are canceled.
  • a MAC object works as follows:
  • the BFR procedure determines that at least one BFR has been triggered and not cancelled for a SCell for which evaluation of candidate beams has been completed, and none of the serving cell(s) of this MAC entity is configured with two BFD RS sets:
  • UL-SCH uplink shared channel
  • SR scheduling request
  • the BFR procedure determines that at least one BFR has been triggered and not cancelled for a SCell for which evaluation of candidate beams has been completed, and at least one serving cell of this MAC entity is set to two BFD RS sets:
  • SR scheduling request
  • All BFRs triggered for a SCell are canceled when a MAC PDU (protocol data unit) is transmitted, which includes a MAC CE for the BFR containing beam failure information of the corresponding SCell.
  • All BFRs triggered for the BFD RS set of the serving cell are canceled when a MAC PDU is transmitted, which includes an Enhanced BFR MAC CE or a Truncated Enhanced BFR MAC CE containing BFR information of the corresponding BFD RS set of the serving cell.
  • Example 2 Candidate beam detection method for link recovery according to NES
  • the UE can measure RS(s) in the candidate beam RS list and transmit a PRACH preamble using a PRACH resource mapped to the best beam RS.
  • the UE can measure L1-RSRP of DL RS (i.e., candidateBeamRS) set to set q 1 (up to 2 ports P-CSI-RS or SSB) and select a specific beam based on the measured L1-RSRP.
  • a base station may separately configure one or multiple candidate beam RSs (i.e., RS list#1) for two antenna ports (APs: antenna ports) and one or multiple candidate beam RSs (i.e., RS list#2) for one AP as follows.
  • the base station may separately configure one or multiple candidate beam RSs (i.e., RS list#1) for one AP having 32 antenna elements and one or multiple candidate beam RSs (i.e., RS list#2) for one AP having 8 antenna elements.
  • the candidate beam RS may be configured as P-CSI-RS or SSB.
  • the candidate beam RS list can be set as shown in Table 6 below.
  • Table 6 illustrates the upper layer parameters for setting the candidate beam RS list.
  • a UE for which multiple candidate beam RS lists are set can perform BFR as follows. For example, if a cell in which beam failure is detected is a PCell or a PSCell, the UE can trigger a BFR random access procedure (i.e., a RACH procedure) as described below.
  • a BFR random access procedure i.e., a RACH procedure
  • the UE can measure L1-RSRP for RSs in the candidate beam RS list and perform a random access procedure using PRACH resources and preambles associated with an optimal RS.
  • the UE can report the beam failure to the base station by transmitting a scheduling request (SR) PUCCH as described below.
  • SR scheduling request
  • the base station allocates PUSCH resources to the UE with MSG2 or MSGB or DCI. Thereafter, the UE reports BFR MAC CE to the base station with the allocated PUSCH resources, and if a new beam is available, the link can be recovered through the new beam.
  • the UE can report an identifier for the new beam(s) and the quality (e.g., RSRP or SINR) for the corresponding beam(s) to the base station through the BFR MAC CE.
  • Method 1 BFR is performed by applying candidate beam RS list#1 or candidate beam RS list#2 according to base station instructions.
  • a UE that has received a higher layer message (e.g., an RRC message) that sets the above candidate beam RSs can receive a DCI or MAC CE or RRC message indicating RS list#1 or RS list#2 from the base station. If beam failure is detected for an activated RS resource set, the UE can perform BFR by applying RS list#1 or RS list#2 according to the above instruction from the base station.
  • a higher layer message e.g., an RRC message
  • the UE may measure L1-RSRP for RSs within a specific candidate beam RS list indicated by the base station, select a specific/optimal RS, and perform a random access procedure by selecting PRACH resources and/or preambles associated therewith.
  • the UE may transmit SR PUCCH for BFR, and report to the base station, through BFR MAC CE, new RS(s) available within the RSs within the specific candidate beam RS list indicated by the base station and the quality (e.g., RSRP or SINR) for the RS(s).
  • the quality e.g., RSRP or SINR
  • Method 2 BFR is performed through a candidate beam RS list mapped to the RS resource set where BFD is detected.
  • the base station can configure multiple RS resource sets (i.e., BFD RS sets, e.g., Periodic CSI-RS resource sets or SSB index sets) for BFD and allow each BFD RS resource set to be mapped to one candidate beam RS list.
  • BFD RS resource set #a can be configured to be mapped to RS list #1
  • BFD RS resource set #b can be configured to be mapped to RS list #2.
  • the UE can perform BFR by applying a specific RS list mapped to the specific BFD RS resource set.
  • the UE may measure L1-RSRP for RSs within a specific candidate beam RS list mapped to the BFD RS set where beam failure is detected, select a specific/optimal RS, and perform a random access procedure by selecting PRACH resources and/or preambles associated therewith.
  • the UE may transmit SR PUCCH for BFR, and report to the base station, through BFR MAC CE, new RS(s) available within the RSs within the specific candidate beam RS list mapped to the BFD RS set where beam failure is detected, and quality (e.g., RSRP or SINR) for the corresponding RS(s).
  • BFR MAC CE new RS(s) available within the RSs within the specific candidate beam RS list mapped to the BFD RS set where beam failure is detected, and quality (e.g., RSRP or SINR) for the corresponding RS(s).
  • Method 3 BFR is performed through a candidate beam RS list that is mapped depending on whether it is in NES mode or not.
  • the base station can instruct the UE to set candidate beam RS list#1 as RS of non-NES mode and candidate beam RS list#2 as RS of NES mode through a higher layer message (e.g., RRC message).
  • a higher layer message e.g., RRC message.
  • the UE can perform BFR by applying RS list#2
  • the UE can perform BFR by applying RS list#1.
  • the UE can operate in the NES mode or the non-NES mode according to the configuration/instruction of the base station or according to a specific rule.
  • the UE may measure L1-RSRP for RSs within the associated specific candidate beam RS list depending on whether the UE operates in NES mode or non-NES mode, and select a specific/optimal RS to perform a random access procedure by selecting PRACH resources and/or preambles associated therewith.
  • the UE may transmit SR PUCCH for BFR, and report to the base station new RS(s) available within the RSs within the associated specific candidate beam RS list depending on whether the UE operates in NES mode or non-NES mode through BFR MAC CE on the resources allocated by the base station, and quality (e.g., RSRP or SINR) for the RS(s).
  • quality e.g., RSRP or SINR
  • the UE can perform BFR only with candidate beam RS list#1 if the base station indicates candidate beam RS list#1, and can perform BFR using both candidate beam RS list#1 and candidate beam RS list#2 if the base station indicates candidate beam RS list#2.
  • the base station may indicate both candidate beam RS list#1 and candidate beam RS list#2, or only candidate beam RS list#1. In this case, if both candidate beam RS list#1 and candidate beam RS list#2 are indicated, the UE may perform BFR using both candidate beam RS list#1 and candidate beam RS list#2.
  • the UE performs BFR using candidate beam RS list#1 preferentially, but may also measure candidate beam RS list#2 and perform BFR using both candidate beam RS list#1 and candidate beam RS list#2.
  • the base station indicates candidate beam RS list#2
  • the UE performs BFR using candidate beam RS list#2 preferentially, but may also measure candidate beam RS list#1 and perform BFR using both candidate beam RS list#1 and candidate beam RS list#2.
  • the base station may transmit beamFailureRecoveryConfig, beamFailureRecoverySpCellConfig, beamFailureRecoverySCellConfig, radioLinkMonitoringConfig, etc., including some or all of the following parameters, to the UE via a higher layer message (e.g., RRC message).
  • a higher layer message e.g., RRC message
  • some or all of the following parameters may be configured/enabled per RS resource set for BFD, per candidate beam RS list for BFR, per NES mode and non-NES mode, or per BFR RACH resource/preamble index set.
  • BeamFailureInstanceMaxCount for BFI maximum count for BFD This parameter determines the number of beam failure events that will trigger BFR for the UE.
  • This parameter indicates a timer for BFR, and a UE whose timer expires will not use contention-free random access for BFR.
  • rsrp-ThresholdSSB for RSRP threshold of SSB Indicates the L1-RSRP threshold used by the UE to determine whether a candidate beam can be used for attempting contention free random access to recover from beam failure.
  • Upper layer parameter rsrp-ThresholdBFR for RSRP threshold of BFR Indicates the L1-RSRP threshold used by the UE to determine whether a candidate beam can be included in the MAC CE for beam failure recovery.
  • This parameter indicates the power ramping step applied for the prioritized random access procedure.
  • This parameter indicates the target power level at the network receiver.
  • preambleTransMax This parameter indicates the maximum number of RA (random access) preamble transmissions performed before declaring a failure.
  • This parameter indicates the number of SSBs per RACH opportunity for contention-free BFR.
  • This parameter indicates the length of the Msg2 (i.e., random access response (RAR)) window in the number of slots.
  • This parameter indicates the PRACH mask index explicitly signaled for random access resource selection.
  • This parameter indicates the random access opportunity (occasion) that the UE should use when performing BFR by selecting the candidate beam identified by this CSI-RS.
  • This parameter indicates a list of RSs (CSI-RS and/or SSB) that identify candidate beams for recovery.
  • This parameter indicates a list of RSs (CSI-RS and/or SSB) that identify candidate beams for recovery.
  • This parameter indicates a list of RSs (CSI-RS and/or SSB) that identify candidate beams for recovery.
  • BFI_COUNTER This variable is incremented by 1 when a BFI is received from a lower layer.
  • the UE upon request to upper layers, the UE provides to upper layers (i.e., MAC) the periodic CSI-RS configuration indices and/or SS/PBCH block indices from the set q 1 or q 1,0 or q 1,1 and the corresponding L1-RSRP measurements greater than or equal to Q in,LR threshold.
  • upper layers i.e., MAC
  • the periodic CSI-RS configuration indices and/or SS/PBCH block indices from the set q 1 or q 1,0 or q 1,1 and the corresponding L1-RSRP measurements greater than or equal to Q in,LR threshold.
  • a UE having corresponding L1-RSRP measurements greater than or equal to Q in,LR threshold informs upper layers whether there is at least one periodic CSI-RS configuration index or SS/PBCH block index from the set q 1 or q 1,0 or q 1,1 , and the UE provides periodic CSI-RS configuration indices and/or SS/PBCH block indices from the set q 1 or q 1,0 or q 1,1 and corresponding L1-RSRP measurements greater than or equal to Q in,LR threshold.
  • FIG. 9 illustrates a signaling method for a beam failure detection method according to one embodiment of the present disclosure.
  • the UE receives configuration information from the base station (S901).
  • the base station can activate or deactivate NES mode operation.
  • the base station can activate or deactivate NES mode operation in units of cells controlled by the base station, and can notify the UE of such NES mode activation or deactivation information through the above-described configuration information.
  • the configuration information may include configuration information related to the BFD procedure and/or the BFR procedure described in the proposed method described above (e.g., Embodiment 1, Embodiment 2, a combination of Embodiments 1 and 2, a combination of the detailed methods in Embodiments 1 and 2).
  • the configuration information may include information about BFD RS set(s) related to the BFD procedure, wherein in some cases, the BFD RS set(s) may not be explicitly configured/indicated.
  • the configuration information may include information about a plurality of RSs (reference signals) (i.e., RSs for which QCL related to spatial reception parameters is set or QCL type D RSs) for a spatial relation assumption (e.g., QCL relation) set for a specific CORESET (/CORESET group).
  • the configuration information may include configuration information about BFRQ resources related to the BFR procedure.
  • one or more multi-antenna port RS(s) within the BFD RS set can be configured.
  • the configuration information may include information about a first BFD RS set (including one or more RSs) and a second BFD RS set (including one or more RSs) (for a specific cell or a group of cells).
  • a first BFD RS set including one or more RSs
  • a second BFD RS set including one or more RSs
  • one or more multi-antenna port RS(s) in the first BFD RS set and the second BFD RS set may be configured.
  • one BFD RS set to be used for BFD may be indicated/activated by explicit configuration/instruction by the base station.
  • one BFD RS set to be used for BFD may be determined/activated implicitly without explicit configuration by the base station (e.g., by using at least one of the methods 1 to 5 of Embodiment 1).
  • a BFD RS set including a CSI-RS indicated by a TCI state for a CORESET (or a CORESET selected from among a plurality of CORESETs used for monitoring) used by the UE for PDCCH monitoring among the first BFD RS set or the second BFD RS set may be selected.
  • a BFD RS set including a CSI-RS indicated by a TCI state determined according to a random access procedure most recently performed by the UE among the first BFD RS set or the second BFD RS set may be selected.
  • a BFD RS set including a CSI-RS QCLed with an SSB having a measurement value equal to or greater than a highest or a predetermined threshold may be selected.
  • the configuration information may include information on one or more parameters to be used for the BFD procedure of the UE.
  • the one or more parameters may include at least one of i) a threshold for a radio link quality used to detect the beam failure, ii) a threshold for a layer 1 reference signal received power (L1-RSRP) measurement value for determining an available RS reported to the base station.
  • L1-RSRP layer 1 reference signal received power
  • the configuration information may include information about a first candidate beam RS list (including one or more RSs) and a second candidate beam RS list (including one or more RSs) (for a specific cell or cell group).
  • one candidate beam RS list to be used for BFR may be determined/activated explicitly/instructed by the base station or implicitly (for example, by using at least one of Schemes 1 to 3 of Embodiment 2, and Additional Schemes A and B).
  • the configuration information may include information on one or more parameters to be used for the BFR procedure of the UE.
  • the base station and UE can apply NES operation (S901).
  • the base station can explicitly transmit information about the NES mode in the configuration information to the UE to notify the application of the NES operation.
  • the base station may indirectly instruct/configure the operation of the NES by transmitting to the UE information about one or more antenna ports that are turned off and/or information about one or more antenna ports that have reduced transmit power.
  • the UE receives BFD RS(s) (according to NES operation) from the base station (S903).
  • the UE can receive RS(s) (e.g., CSI-RS, SSB) within the configured BFD RS set.
  • RS(s) e.g., CSI-RS, SSB
  • the UE when multiple BFD RS sets are set by the base station, the UE can receive RS(s) (e.g., CSI-RS, SSB) within the multiple BFD RS sets.
  • RS(s) e.g., CSI-RS, SSB
  • the UE may also receive activation/selection information for one BFD RS among multiple BFD RS sets from the base station (e.g., by MAC CE, DCI, etc.). Or, according to the embodiment 1 described above, one specific BFD RS set may be implicitly selected among multiple BFD RS sets.
  • the UE detects beam failure by assessing the radio link quality for the BFD RS set (S904).
  • the UE can detect a beam failure by assessing the radio link quality (e.g., BLER) for all RS(s) in the configured BFD RS set. Specifically, the physical layer of the UE transmits a BFI to the upper layer (i.e., MAC) if the radio link quality (e.g., BLER) for all RS(s) in the configured BFD RS set is worse than a threshold.
  • the upper layer (i.e., MAC) of the UE can declare a beam failure if the number of receptions of the BFI is greater than a certain threshold.
  • the UE can detect a beam failure using one or more parameter(s) related to BFD (and/or BFR) set by the base station. Additionally, a positive or negative offset can be applied to the one or more parameters based on some of the multi-antenna ports being turned off or having reduced transmission power for one or more RS(s) in the BFD RS set.
  • the UE when multiple BFD RS sets are configured by the base station, the UE can detect beam failure by assessing the radio link quality for all RS(s) in the active/selected BFD RS set among the multiple BFD RS sets.
  • a positive or negative offset may be applied to one or more of the parameters based on some of the multiple antenna ports for one or more RS(s) in the active/selected BFD RS set among the multiple BFD RS sets being turned off or having a reduced transmission power.
  • the UE may receive information from the base station about some of the multiple antenna ports that are turned off or have reduced transmission power.
  • the offset can be set per cell, per bandwidth part (BWP), per frequency, per BFD RS set, per antenna port, per antenna port group, and/or per antenna element group.
  • BWP bandwidth part
  • per frequency per frequency
  • per BFD RS set per antenna port
  • per antenna port group per antenna port group
  • per antenna element group per antenna element group
  • the UE receives candidate RS(s) (or candidate beam RS list) for BFR from the base station (S905).
  • step S905 in FIG. 9 is depicted as being performed after steps S903 and S904 for convenience of explanation, but step S905 does not necessarily have to be performed after steps S903 and S904.
  • the UE performs measurements (e.g., L1-RSRP, L1-SINR) of candidate RS(s) (or candidate beam RS list) for the received BFR.
  • measurements e.g., L1-RSRP, L1-SINR
  • the UE when a plurality of candidate beam RS lists are set by the base station, the UE can perform reception and/or measurement (e.g., L1-RSRP, L1-SINR) for RS(s) in the activated/selected candidate RS list among the plurality of BFD RS sets.
  • the UE may also receive activation/selection information for a candidate beam RS list among the plurality of candidate RS lists from the base station (e.g., by MAC CE, DCI, etc.).
  • a specific candidate RS list may be implicitly selected among the plurality of candidate RS lists.
  • the UE performs uplink transmission for BFR to the base station (S906).
  • the UE can perform the BFR procedure based on the proposed method described above (e.g., embodiment 1, embodiment 2, a combination of embodiments 1 and 2, a combination of detailed methods within embodiments 1 and 2).
  • the UE can transmit PRACH using PRACH resource (and/or PRACH preamble) associated (directly or indirectly) with the best beam RS (CSI-RS or SSB) in the candidate RS list.
  • PRACH resource and/or PRACH preamble associated (directly or indirectly) with the best beam RS (CSI-RS or SSB) in the candidate RS list.
  • CSI-RS or SSB best beam RS
  • the UE may transmit BFR PUCCH (i.e., SR transmission for BFR) to the base station on the SpCell.
  • the UE may transmit BFR MAC CE on the uplink resources allocated by the base station.
  • the BFR MAC CE may include the presence or absence of a new beam for the corresponding SCell(s), the beam RS ID if a new beam exists, and the quality(s) (e.g., RSRP or SINR) of the corresponding beam RS(s).
  • FIG. 10 is a diagram illustrating the operation of a UE for a beam failure detection method according to one embodiment of the present disclosure.
  • FIG. 10 illustrates an operation of a UE based on the previously proposed methods (e.g., Embodiment 1, Embodiment 2, a combination of Embodiments 1 and 2, a combination of detailed methods within Embodiments 1 and 2).
  • the example of FIG. 10 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some step(s) illustrated in FIG. 10 may be omitted depending on situations and/or settings.
  • the UE in FIG. 10 is only an example and may be implemented as a device illustrated in FIG. 12 below.
  • the processor (102/202) of FIG. 12 may control the transceiver (106/206) to transmit and receive channels/signals/data/information, etc., and may also control the processor (102/202) of FIG. 12 to store transmitted or received channels/signals/data/information, etc. in the memory (104/204).
  • FIG. 10 may be processed by one or more processors (102, 202) of FIG. 12, and the operation of FIG. 10 may be stored in a memory (e.g., one or more memories (104, 204) of FIG. 12) in the form of a command/program (e.g., an instruction, an executable code) for driving at least one processor (e.g., 102, 202) of FIG. 12.
  • a command/program e.g., an instruction, an executable code
  • the UE receives first configuration information including information about a BFD RS set (hereinafter, a first BFD RS set) from a base station and second configuration information including information about one or more parameters related to BFD and/or BFR (S1001).
  • first configuration information including information about a BFD RS set (hereinafter, a first BFD RS set) from a base station and second configuration information including information about one or more parameters related to BFD and/or BFR (S1001).
  • one or more multi-antenna port RS(s) within the first BFD RS set can be configured.
  • the configuration information may include information about a first BFD RS set (including one or more RSs) and a second BFD RS set (including one or more RSs) (for a specific cell or a group of cells).
  • a first BFD RS set including one or more RSs
  • a second BFD RS set including one or more RSs
  • the configuration information may include information about a first BFD RS set (including one or more RSs) and a second BFD RS set (including one or more RSs) (for a specific cell or a group of cells).
  • one or more multi-antenna port RS(s) in the first BFD RS set and the second BFD RS set may be configured.
  • one BFD RS set to be used for BFD may be indicated/activated by explicit configuration/instruction by the base station.
  • one BFD RS set to be used for BFD may be determined/activated implicitly without explicit configuration by the base station (e.g., by using at least
  • a BFD RS set including a CSI-RS indicated by a TCI state for a CORESET (or a CORESET selected from among a plurality of CORESETs used for monitoring) used by the UE for PDCCH monitoring among the first BFD RS set or the second BFD RS set may be selected.
  • a BFD RS set including a CSI-RS indicated by a TCI state determined according to a random access procedure most recently performed by the UE among the first BFD RS set or the second BFD RS set may be selected.
  • a BFD RS set including a CSI-RS QCLed with an SSB having a measurement value equal to or greater than a highest or a predetermined threshold may be selected.
  • the one or more parameters may include at least one of i) a threshold for a radio link quality used to detect the beam failure, ii) a threshold for a layer 1 reference signal received power (L1-RSRP) measurement value for determining an available RS reported to the base station.
  • L1-RSRP layer 1 reference signal received power
  • the one or more parameters in the second setting information can be individually set for the first BFD RS set and the second BFD RS set.
  • the UE assesses the radio link quality for the BFD RS set (S1002).
  • the UE can receive RS(s) (e.g., CSI-RS, SSB) within the configured BFD RS set and evaluate radio link quality (e.g., BLER).
  • RS(s) e.g., CSI-RS, SSB
  • radio link quality e.g., BLER
  • the UE when multiple BFD RS sets are set by the base station, the UE can receive RS(s) (e.g., CSI-RS, SSB) within the multiple BFD RS sets and evaluate radio link quality (e.g., BLER).
  • RS(s) e.g., CSI-RS, SSB
  • radio link quality e.g., BLER
  • the UE may also receive activation/selection information for one BFD RS among multiple BFD RS sets from the base station (e.g., by MAC CE, DCI, etc.). Or, according to the embodiment 1 described above, one specific BFD RS set may be implicitly selected among multiple BFD RS sets.
  • the UE Based on the detection of beam failure, the UE performs uplink transmission for BFR to the base station (S1003).
  • the UE can detect beam failure by assessing the radio link quality (e.g., BLER) for all RS(s) in the configured BFD RS set. Additionally, when multiple BFD RS sets are configured by the base station, the UE can detect beam failure by assessing the radio link quality (e.g., BLER) for all RS(s) in the BFD RS set that is instructed to be activated (or implicitly selected).
  • the radio link quality e.g., BLER
  • the physical layer of the UE forwards a BFI to the upper layer (i.e., MAC) if the radio link quality (e.g., BLER) for all RS(s) in the configured BFD RS set is worse than a threshold.
  • the upper layer of the UE i.e., MAC
  • the UE can detect a beam failure using one or more parameter(s) related to BFD (and/or BFR) set by the base station. Additionally, a positive or negative offset can be applied to the one or more parameters based on some of the multi-antenna ports being turned off or having reduced transmission power for one or more RS(s) in the BFD RS set.
  • the UE when multiple BFD RS sets are configured by the base station, the UE can detect beam failure by assessing the radio link quality for all RS(s) in the active/selected BFD RS set among the multiple BFD RS sets.
  • a positive or negative offset may be applied to one or more of the parameters based on some of the multiple antenna ports for one or more RS(s) in the active/selected BFD RS set among the multiple BFD RS sets being turned off or having a reduced transmission power.
  • the UE may receive information from the base station about some of the multiple antenna ports that are turned off or have reduced transmission power.
  • the offset can be set per cell, per bandwidth part (BWP), per frequency, per BFD RS set, per antenna port, per antenna port group, and/or per antenna element group.
  • BWP bandwidth part
  • per frequency per frequency
  • per BFD RS set per antenna port
  • per antenna port group per antenna port group
  • per antenna element group per antenna element group
  • the UE When a beam failure is detected in the above manner, the UE performs an uplink transmission for BFR to the base station. That is, the UE can perform the BFR procedure based on the proposed method described above (e.g., Embodiment 1, Embodiment 2, a combination of Embodiments 1 and 2, a combination of detailed methods in Embodiments 1 and 2).
  • the UE can transmit PRACH using PRACH resource (and/or PRACH preamble) associated (directly or indirectly) with the best beam RS (CSI-RS or SSB) in the candidate RS list.
  • PRACH resource and/or PRACH preamble associated (directly or indirectly) with the best beam RS (CSI-RS or SSB) in the candidate RS list.
  • CSI-RS or SSB best beam RS
  • the UE may transmit BFR PUCCH (i.e., SR transmission for BFR) to the base station on the SpCell.
  • the UE may transmit BFR MAC CE on the uplink resources allocated by the base station.
  • the BFR MAC CE may include the presence or absence of a new beam for the corresponding SCell(s), the beam RS ID if a new beam exists, and the quality(s) (e.g., RSRP or SINR) of the corresponding beam RS(s).
  • FIG. 11 is a diagram illustrating the operation of a base station for a beam failure detection method according to one embodiment of the present disclosure.
  • FIG. 11 illustrates an operation of a base station based on the proposed methods (e.g., Embodiment 1, Embodiment 2, a combination of Embodiments 1 and 2, a combination of detailed methods within Embodiments 1 and 2).
  • the example of FIG. 11 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some step(s) illustrated in FIG. 11 may be omitted depending on circumstances and/or settings.
  • the base station in FIG. 11 is only an example and may be implemented as a device illustrated in FIG. 12 below.
  • the processor (102/202) of FIG. 12 may control the transceiver (106/206) to transmit and receive channels/signals/data/information, etc., and may also control the processor (102/202) of FIG. 12 to store transmitted or received channels/signals/data/information, etc. in the memory (104/204).
  • FIG. 10 may be processed by one or more processors (102, 202) of FIG. 12, and the operation of FIG. 10 may be stored in a memory (e.g., one or more memories (104, 204) of FIG. 12) in the form of a command/program (e.g., an instruction, an executable code) for driving at least one processor (e.g., 102, 202) of FIG. 12.
  • a command/program e.g., an instruction, an executable code
  • the base station transmits to the UE first configuration information including information about a BFD RS set (hereinafter, a first BFD RS set) and second configuration information including information about one or more parameters related to BFD and/or BFR (S1101).
  • first configuration information including information about a BFD RS set (hereinafter, a first BFD RS set) and second configuration information including information about one or more parameters related to BFD and/or BFR (S1101).
  • one or more multi-antenna port RS(s) within the first BFD RS set can be configured.
  • one or more multi-antenna port RS(s) within the first BFD RS set and/or the second BFD RS set can be set.
  • the configuration information may include information about a first BFD RS set (including one or more RSs) and a second BFD RS set (including one or more RSs) (for a specific cell or a group of cells).
  • a first BFD RS set including one or more RSs
  • a second BFD RS set including one or more RSs
  • the configuration information may include information about a first BFD RS set (including one or more RSs) and a second BFD RS set (including one or more RSs) (for a specific cell or a group of cells).
  • one or more multi-antenna port RS(s) in the first BFD RS set and the second BFD RS set may be configured.
  • one BFD RS set to be used for BFD may be indicated/activated by explicit configuration/instruction by the base station.
  • one BFD RS set to be used for BFD may be determined/activated implicitly without explicit configuration by the base station (e.g., by using at least
  • a BFD RS set including a CSI-RS indicated by a TCI state for a CORESET (or a CORESET selected from among a plurality of CORESETs used for monitoring) used by the UE for PDCCH monitoring among the first BFD RS set or the second BFD RS set may be selected.
  • a BFD RS set including a CSI-RS indicated by a TCI state determined according to a random access procedure most recently performed by the UE among the first BFD RS set or the second BFD RS set may be selected.
  • a BFD RS set including a CSI-RS QCLed with an SSB having a measurement value equal to or greater than a highest or a predetermined threshold may be selected.
  • the one or more parameters may include at least one of i) a threshold for a radio link quality used to detect the beam failure, ii) a threshold for a layer 1 reference signal received power (L1-RSRP) measurement value for determining an available RS reported to the base station.
  • L1-RSRP layer 1 reference signal received power
  • the one or more parameters in the second setting information can be individually set for the first BFD RS set and the second BFD RS set.
  • the base station Based on the detection of beam failure in the assessment of radio link quality for the BFD RS set by the UE, the base station receives an uplink transmission for BFR from the UE (S1102).
  • the UE can receive RS(s) (e.g., CSI-RS, SSB) within the configured BFD RS set and evaluate radio link quality (e.g., BLER).
  • RS(s) e.g., CSI-RS, SSB
  • radio link quality e.g., BLER
  • the UE when multiple BFD RS sets are set by the base station, the UE can receive RS(s) (e.g., CSI-RS, SSB) within the multiple BFD RS sets and evaluate radio link quality (e.g., BLER).
  • RS(s) e.g., CSI-RS, SSB
  • radio link quality e.g., BLER
  • the base station may also transmit activation/selection information for one BFD RS among multiple BFD RS sets to the UE (e.g., by MAC CE, DCI, etc.). Or, according to the above-described embodiment 1, a specific one BFD RS set may be implicitly selected among multiple BFD RS sets.
  • the UE can detect beam failure by assessing the radio link quality (e.g., BLER) for all RS(s) in the configured BFD RS set. Additionally, when multiple BFD RS sets are configured by the base station, the UE can detect beam failure by assessing the radio link quality (e.g., BLER) for all RS(s) in the BFD RS set that is instructed to be activated (or implicitly selected).
  • the radio link quality e.g., BLER
  • the physical layer of the UE forwards a BFI to the upper layer (i.e., MAC) if the radio link quality (e.g., BLER) for all RS(s) in the configured BFD RS set is worse than a threshold.
  • the upper layer of the UE i.e., MAC
  • the UE can detect a beam failure using one or more parameter(s) related to BFD (and/or BFR) set by the base station. Additionally, a positive or negative offset can be applied to the one or more parameters based on some of the multi-antenna ports being turned off or having reduced transmission power for one or more RS(s) in the BFD RS set.
  • the UE when multiple BFD RS sets are configured by the base station, the UE can detect beam failure by assessing the radio link quality for all RS(s) in the active/selected BFD RS set among the multiple BFD RS sets.
  • a positive or negative offset may be applied to one or more of the parameters based on some of the multiple antenna ports for one or more RS(s) in the active/selected BFD RS set among the multiple BFD RS sets being turned off or having a reduced transmission power.
  • the base station may transmit to the UE information about some of the antenna ports among the multiple antenna ports that are turned off or have reduced transmission power.
  • the offset can be set per cell, per bandwidth part (BWP), per frequency, per BFD RS set, per antenna port, per antenna port group, and/or per antenna element group.
  • BWP bandwidth part
  • per frequency per frequency
  • per BFD RS set per antenna port
  • per antenna port group per antenna port group
  • per antenna element group per antenna element group
  • the UE When a beam failure is detected in the above manner, the UE performs an uplink transmission for BFR to the base station. That is, the UE can perform the BFR procedure based on the proposed method described above (e.g., Embodiment 1, Embodiment 2, a combination of Embodiments 1 and 2, a combination of detailed methods in Embodiments 1 and 2).
  • the base station can receive PRACH using PRACH resource (and/or PRACH preamble) associated (directly or indirectly) with the best beam RS (CSI-RS or SSB) in the candidate RS list from the UE.
  • PRACH resource and/or PRACH preamble
  • CSI-RS or SSB the best beam RS
  • the base station can receive BFR PUCCH (i.e., SR transmission for BFR) on SpCell from the UE.
  • BFR PUCCH i.e., SR transmission for BFR
  • the base station can receive BFR MAC CE on the allocated uplink resources from the UE.
  • the BFR MAC CE can include the presence or absence of a new beam for the corresponding SCell(s), the beam RS ID if a new beam exists, and the quality(s) (e.g., RSRP or SINR) of the corresponding beam RS(s).
  • FIG. 12 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.
  • the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR).
  • various wireless access technologies e.g., LTE, NR.
  • a first wireless device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and/or one or more antennas (108).
  • the processor (102) controls the memory (104) and/or the transceiver (106), and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in the present disclosure.
  • the processor (102) may process information in the memory (104) to generate first information/signal, and then transmit a wireless signal including the first information/signal via the transceiver (106).
  • the processor (102) may receive a wireless signal including second information/signal via the transceiver (106), and then store information obtained from signal processing of the second information/signal in the memory (104).
  • the memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software codes including commands for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure.
  • the processor (102) and the memory (104) may be part of a communication modem/circuit/chip designed to implement wireless communication technology (e.g., LTE, NR).
  • the transceiver (106) may be connected to the processor (102) and may transmit and/or receive wireless signals via one or more antennas (108).
  • the transceiver (106) may include a transmitter and/or a receiver.
  • the transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit.
  • a wireless device may also mean a communication modem/circuit/chip.
  • the second wireless device (200) includes one or more processors (202), one or more memories (204), and may additionally include one or more transceivers (206) and/or one or more antennas (208).
  • the processor (202) controls the memories (204) and/or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this disclosure.
  • the processor (202) may process information in the memory (204) to generate third information/signals, and then transmit a wireless signal including the third information/signals via the transceivers (206).
  • the processor (202) may receive a wireless signal including fourth information/signals via the transceivers (206), and then store information obtained from signal processing of the fourth information/signals in the memory (204).
  • the memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software codes including commands for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure.
  • the processor (202) and the memory (204) may be part of a communication modem/circuit/chip designed to implement wireless communication technology (e.g., LTE, NR).
  • the transceiver (206) may be connected to the processor (202) and may transmit and/or receive wireless signals via one or more antennas (208).
  • the transceiver (206) may include a transmitter and/or a receiver.
  • the transceiver (206) may be used interchangeably with an RF unit.
  • a wireless device may also mean a communication modem/circuit/chip.
  • one or more protocol layers may be implemented by one or more processors (102, 202).
  • one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP).
  • One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure.
  • PDUs Protocol Data Units
  • SDUs Service Data Units
  • One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure.
  • One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, suggestions and/or methodologies disclosed in this disclosure, and provide the signals to one or more transceivers (106, 206).
  • One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this disclosure.
  • signals e.g., baseband signals
  • the one or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer.
  • the one or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof.
  • ASICs Application Specific Integrated Circuits
  • DSPs Digital Signal Processors
  • DSPDs Digital Signal Processing Devices
  • PLDs Programmable Logic Devices
  • FPGAs Field Programmable Gate Arrays
  • the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc.
  • the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software configured to perform one or more of the following: included in one or more processors (102, 202), or stored in one or more memories (104, 204) and driven by one or more of the processors (102, 202).
  • the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software in the form of codes, instructions and/or sets of instructions.
  • One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions and/or commands.
  • the one or more memories (104, 204) may be comprised of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer readable storage media and/or combinations thereof.
  • the one or more memories (104, 204) may be located internally and/or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.
  • One or more transceivers (106, 206) can transmit user data, control information, wireless signals/channels, etc., as described in the methods and/or flowcharts of the present disclosure, to one or more other devices.
  • One or more transceivers (106, 206) can receive user data, control information, wireless signals/channels, etc., as described in the descriptions, functions, procedures, suggestions, methods and/or flowcharts of the present disclosure, from one or more other devices.
  • one or more transceivers (106, 206) can be coupled to one or more processors (102, 202) and can transmit and receive wireless signals.
  • one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals/channels, and the like, as described in the description, function, procedure, proposal, method, and/or operational flowchart, etc.
  • one or more antennas may be multiple physical antennas, or multiple logical antennas (e.g., antenna ports).
  • One or more transceivers (106, 206) may convert received user data, control information, wireless signals/channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals/channels, etc. using one or more processors (102, 202).
  • One or more transceivers (106, 206) may convert processed user data, control information, wireless signals/channels, etc. from baseband signals to RF band signals using one or more processors (102, 202).
  • one or more transceivers (106, 206) may include an (analog) oscillator and/or filter.
  • the scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to the various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer.
  • Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on/in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure.
  • the storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices, and can include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices.
  • the memory optionally includes one or more storage devices remotely located from the processor(s).
  • the memory or alternatively the non-volatile memory device(s) within the memory comprises a non-transitory computer readable storage medium.
  • the features described in this disclosure may be incorporated into software and/or firmware stored on any one of the machine readable media to control the hardware of the processing system and to allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure.
  • Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments/containers.
  • the wireless communication technology implemented in the wireless device (100, 200) of the present disclosure may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication.
  • NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and/or LTE Cat NB2, and is not limited to the above-described names.
  • the wireless communication technology implemented in the wireless device (XXX, YYY) of the present disclosure may perform communication based on LTE-M technology.
  • LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication).
  • the LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and is not limited to the above-described names.
  • the wireless communication technology implemented in the wireless device (XXX, YYY) of the present disclosure can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names.
  • ZigBee technology can create PAN (personal area networks) related to small/low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.
  • the method proposed in this disclosure has been described with a focus on examples applied to 3GPP LTE/LTE-A and 5G systems, but it can be applied to various wireless communication systems in addition to 3GPP LTE/LTE-A and 5G systems.

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Abstract

La présente invention divulgue un procédé et un dispositif de détection d'une défaillance de faisceau (BFD) dans un système de communication sans fil. Un procédé mis en œuvre par un UE dans un système de communication sans fil, selon un mode de réalisation de la présente divulgation, peut comprendre les étapes consistant à : recevoir, d'une station de base, des premières informations de configuration et des secondes informations de configuration, les premières informations de configuration incluant des informations concernant un premier ensemble de signaux BFD RS, et les secondes informations de configuration incluant des informations concernant un ou plusieurs paramètres associés à une défaillance BFD et/ou une reprise BFR ; évaluer la qualité de liaison sans fil pour le premier ensemble de signaux BFD RS ; et réaliser une transmission de liaison montante pour la reprise BFR vers la station de base sur la base de la détection d'une défaillance de faisceau pour le premier ensemble de signaux BFD RS.
PCT/KR2024/095350 2023-02-16 2024-02-16 Procédé et dispositif de détection d'une défaillance de faisceau dans un système de communication sans fil WO2024172627A1 (fr)

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Citations (5)

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