Method for performing communication and device for same in wireless communication system

Abstract

A first device according to various embodiments may: receive, from a second device, measurement configuration information for an event-trigger-based measurement report related to mobility; measure cell quality for each of one or more candidate cells on the basis of the measurement configuration information; and determine an event-trigger-related event instance on the basis of the cell quality of each of the one or more candidate cells.

Description

Method for performing communication in a wireless communication system and device therefor

[0001] The present invention relates to a method for a terminal to perform measurement and reporting in a wireless communication system and a device therefor.

[0002] Wireless communication systems are multiple access systems that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0003] As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Furthermore, massive Machine Type Communications (MTC), which connects numerous devices and objects to provide various services anytime, anywhere, is also a key issue to be considered in next-generation communication. Furthermore, communication system design that considers reliability and latency-sensitive services / terminals is being discussed. The introduction of next-generation radio access technologies that take into account enhanced mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) is being discussed. For convenience, these technologies are referred to as new RAT or NR in the present invention.

[0004] The technical challenge is to provide a method for terminals to perform mobility-related event-triggered measurement reporting more accurately and efficiently.

[0005] The technical challenges are not limited to the technical challenges mentioned above, and other technical challenges not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0006] A method according to one aspect includes the steps of: receiving, by a first device, measurement configuration information for an event-triggered measurement report related to mobility from a second device; measuring, by the first device, a cell quality for each of at least one candidate cell based on the measurement configuration information; and determining, by the first device, an event instance related to the event-trigger based on the cell quality of each of the at least one candidate cell, wherein the cell quality of each of the at least one candidate cell can be measured based on a synchronization signal block (SSB) of a specific index among a plurality of SSBs configured for each of the at least one candidate cell.

[0007] Alternatively, the specific index may be determined based on the number of associated CSI-RS (Channel State Information-Reference Signal) resources for each of the plurality of SSBs.

[0008] Alternatively, the specific index may be determined as the index of an SSB having the largest number of associated CSI-RS (Channel State Information-Reference Signal) resources among the plurality of SSBs.

[0009] Alternatively, the specific index may be determined as the highest index among the indices of the plurality of SSBs.

[0010] Alternatively, the specific index may be determined as the lowest index among the indices of the plurality of SSBs.

[0011] Alternatively, the specific index may be indicated by the second device for each of the at least one candidate cell.

[0012] Alternatively, the measurement setting information includes information on a specific threshold quality and a specific threshold number that are event trigger conditions, and the first device can determine an event instance of a specific candidate cell among the at least one candidate cell based on the quality of the specific candidate cell being equal to or greater than the specific threshold quality.

[0013] Alternatively, based on the number of said event instances being greater than or equal to the specified threshold number, the first device may trigger the event-triggered measurement report.

[0014] Alternatively, the measurement setup information may be related to LTM (L1 / L2 Triggered Mobility).

[0015] In another aspect, at least one non-transitory computer-readable recording medium comprises instructions that, when executed by at least one processor, perform operations, the operations comprising: receiving, by a first device, measurement configuration information for an event-triggered measurement report related to mobility from a second device; measuring, by the first device, a cell quality for each of at least one candidate cell based on the measurement configuration information; and determining, by the first device, an event instance related to the event-trigger based on the cell quality of each of the at least one candidate cell, wherein the cell quality of each of the at least one candidate cell can be measured based on a synchronization signal block (SSB) of a specific index among a plurality of SSBs configured for each of the at least one candidate cell.

[0016] According to another aspect, a first device includes a Radio Frequency (RF) transceiver; and a processor connected to the RF transceiver, wherein the processor controls the RF transceiver to receive measurement configuration information for an event-triggered measurement report related to mobility from a second device, measures cell quality for each of at least one candidate cell based on the measurement configuration information, and determines an event instance related to the event-trigger based on the cell quality of each of the at least one candidate cell, wherein the cell quality of each of the at least one candidate cell can be measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

[0017] Alternatively, the specific index may be determined based on the number of associated CSI-RS (Channel State Information-Reference Signal) resources for each of the plurality of SSBs.

[0018] In another aspect, a processing device for controlling a first device comprises at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions, when executed by the at least one processor, cause the first device to: receive measurement configuration information for an event-triggered measurement report related to mobility from a second device; measure cell quality for each of at least one candidate cell based on the measurement configuration information; and cause the first device to determine an event instance related to the event-trigger based on the cell quality of each of the at least one candidate cell, wherein the cell quality of each of the at least one candidate cell can be measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

[0019] In another aspect, the method comprises the steps of: transmitting, by a second device, measurement configuration information for an event-triggered measurement report related to mobility to a first device; and receiving, by the first device, the measurement report event-triggered based on a cell quality for each of at least one candidate cell, wherein the cell quality of each of the at least one candidate cell can be measured based on a synchronization signal block (SSB) of a specific index among a plurality of SSBs configured for each of the at least one candidate cell.

[0020] According to another aspect, a second device includes a Radio Frequency (RF) transceiver; and a processor connected to the RF transceiver, wherein the processor controls the RF transceiver to transmit measurement configuration information for an event-triggered measurement report related to mobility to a first device, and receives the measurement report event-triggered by the first device based on cell quality for each of at least one candidate cell, wherein the cell quality of each of the at least one candidate cell can be measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

[0021] Various embodiments enable a terminal to accurately and efficiently perform event-triggered measurement reporting related to mobility. Alternatively, in one example, defining an event at the candidate cell level in the relevant event-triggered report effectively ensures that measurement reports consistent with the purpose of a handover decision are event-triggered by the first device.

[0022] The effects that can be obtained in various embodiments are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0023] The drawings attached to this specification are intended to provide an understanding of the present invention, illustrate various embodiments of the present invention, and together with the description of the specification serve to explain the principles of the present invention.

[0024] Figure 1 shows the structure of an LTE system.

[0025] Figure 2 shows the structure of the NR system.

[0026] Figure 3 shows the structure of a radio frame of NR.

[0027] Figure 4 shows the slot structure of an NR frame.

[0028] FIG. 5 is a diagram for explaining physical channels that can be used in various embodiments and a signal transmission method using the same.

[0029] Figure 6 illustrates a process in which a terminal transmits ACK / NACK via PUSCH.

[0030] Figure 7 shows an example of a CSI-related procedure.

[0031] Figure 8 illustrates an example of an LTM procedure.

[0032] FIG. 9 is a diagram illustrating a method for a UE to determine an event trigger in relation to mobility.

[0033] FIG. 10 is a diagram illustrating a method for a first device to perform event trigger-based measurement reporting related to mobility.

[0034] FIG. 11 is a diagram illustrating a method for a second device to receive a mobility-related event trigger-based measurement report from a first device.

[0035] Figure 12 illustrates a communication system applied to the present invention.

[0036] Figure 13 illustrates a wireless device applicable to the present invention.

[0037] Fig. 14 shows another example of a wireless device applied to the present invention.

[0038] A wireless communication system is a multiple access system that supports communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0039] Sidelink refers to a communication method that establishes a direct link between user equipment (UE), allowing voice or data to be exchanged directly between terminals without going through a base station (BS). Sidelink is being considered as a solution to address the burden on base stations due to rapidly increasing data traffic.

[0040] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects through wired / wireless communication. V2X can be divided into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through the PC5 interface and / or Uu interface.

[0041] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed. Next-generation wireless access technologies that consider improved mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) can be called new radio access technology (RAT) or new radio (NR). NR can also support V2X (vehicle-to-everything) communication.

[0042] The following technologies can be used in various wireless communication systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). 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 (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, providing backward compatibility with systems based on IEEE 802.16e. UTRA is 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 (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink.LTE-A (advanced) is an evolution of 3GPP LTE.

[0043] 5G NR, the successor to LTE-A, is a new clean-slate mobile communications system featuring high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, mid-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz.

[0044] For clarity, the description will focus on LTE-A or 5G NR, but the technical ideas of the embodiment(s) are not limited thereto.

[0045] Figure 1 illustrates the architecture of an applicable LTE system. This may be referred to as an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) or a Long Term Evolution (LTE) / LTE-A system.

[0046] Referring to FIG. 1, the E-UTRAN includes a base station (20; BS) that provides a control plane and a user plane to a terminal (10). The terminal (10) may be fixed or mobile, and may be referred to by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, etc. The base station (20) refers to a fixed station that communicates with the terminal (10), and may be referred to by other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, etc.

[0047] Base stations (20) can be connected to each other via the X2 interface. The base station (20) is connected to an EPC (Evolved Packet Core, 30) via the S1 interface, more specifically, to an MME (Mobility Management Entity) via the S1-MME, and to an S-GW (Serving Gateway) via the S1-U.

[0048] The EPC (30) consists of an MME, an S-GW, and a P-GW (Packet Data Network-Gateway). The MME holds information about terminal access and capabilities, and this information is primarily used for terminal mobility management. The S-GW is a gateway with the E-UTRAN as its endpoint, and the P-GW is a gateway with the PDN as its endpoint.

[0049] The layers of the radio interface protocol between the terminal and the network can be divided into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the three lower layers of the Open System Interconnection (OSI) standard model, which is widely known in communication systems. Among these, the physical layer belonging to Layer 1 provides an information transfer service using a physical channel, and the RRC (Radio Resource Control) layer located in Layer 3 controls radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0050] Figure 2 shows the structure of the NR system.

[0051] Referring to FIG. 2, the NG-RAN may include a gNB and / or an eNB that provides user plane and control plane protocol termination to the UE. FIG. 1 illustrates a case where only a gNB is included. The gNB and eNB are connected to each other via an Xn interface. The gNB and eNB are connected to the 5th generation core network (5G Core Network: 5GC) via the NG interface. More specifically, the gNB is connected to the access and mobility management function (AMF) via the NG-C interface, and the gNB is connected to the user plane function (UPF) via the NG-U interface.

[0052] Figure 3 shows the structure of a radio frame of NR.

[0053] Referring to FIG. 3, radio frames can be used for uplink and downlink transmission in NR. A radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (Half-Frames, HF). A half-frame can include five 1 ms sub-frames (Subframes, SF). A sub-frame can be divided into one or more slots, and the number of slots within a sub-frame can be determined by the Subcarrier Spacing (SCS). Each slot can include 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP).

[0054] When normal CP is used, each slot can contain 14 symbols. When extended CP is used, each slot can contain 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0055] Table 1 below shows the number of symbols per slot ((N)) depending on the SCS setting (u) when normal CP is used. slot symb ), number of slots per frame ((N frame,u slot ) and the number of slots per subframe ((N subframe,u slot ) is an example.

[0056] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 15KHz (u=0)1410130KHz (u=1)1420260KHz (u=2)14404120KHz (u=3)14808240KHz (u=4)1416016

[0057] Table 2 illustrates the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to SCS when extended CP is used.

[0058] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0059] In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, etc.) can be configured differently across multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (conveniently referred to as a TU (Time Unit)) consisting of the same number of symbols can be configured differently across the merged cells. In NR, multiple numerologies or SCSs can be supported to support various 5G services. For example, when the SCS is 15 kHz, a wide area in traditional cellular bands can be supported, and when the SCS is 30 kHz / 60 kHz, dense-urban, lower latency, and wider carrier bandwidth can be supported. When the SCS is 60 kHz or higher, bandwidths greater than 24.25 GHz may be supported to overcome phase noise.

[0060] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges can be FR1 and FR2. The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges can be as shown in Table 3 below. Among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

[0061] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0062] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 4 below. That is, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for vehicular communications (e.g., autonomous driving).

[0063] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0064] Figure 4 shows the slot structure of an NR frame.

[0065] Referring to Figure 4, a slot includes multiple symbols in the time domain. For example, in the case of a normal CP, one slot may include 14 symbols, but in the case of an extended CP, one slot may include 12 symbols. Alternatively, in the case of a normal CP, one slot may include 7 symbols, but in the case of an extended CP, one slot may include 6 symbols.

[0066] A carrier includes multiple subcarriers in the frequency domain. An RB (Resource Block) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain, and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through activated BWPs. Each element can be referred to as a Resource Element (RE) in the resource grid, and one complex symbol can be mapped to it.

[0067] Meanwhile, the wireless interface between terminals or between terminals and a network may be composed of an L1 layer, an L2 layer, and an L3 layer. In various embodiments of the present disclosure, the L1 layer may refer to a physical layer. Furthermore, for example, the L2 layer may refer to at least one of a MAC layer, an RLC layer, a PDCP layer, and an SDAP layer. Furthermore, for example, the L3 layer may refer to an RRC layer.

[0068] Bandwidth part (BWP)

[0069] 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 RF on for the entire CC, the terminal battery consumption may increase. Alternatively, when considering multiple use cases (e.g., eMBB, URLLC, MMTC, V2X, etc.) operating within a wideband CC, different numerologies (e.g., sub-carrier spacing) may be supported for each frequency band within the CC. Alternatively, each terminal may have different capabilities for maximum bandwidth. Considering this, the base station can instruct the terminal to operate only in a portion of the bandwidth rather than the entire bandwidth of the wideband CC, and this portion of bandwidth is conveniently defined as a bandwidth part (BWP). A BWP can be composed of consecutive resource blocks (RBs) on the frequency axis and can correspond to a single numerology (e.g., sub-carrier spacing, CP length, slot / mini-slot duration).

[0070] Meanwhile, the base station can set multiple BWPs even within a single CC configured for the UE. 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. Alternatively, if UEs are concentrated in a specific BWP, some UEs can be set to a different BWP for load balancing. Alternatively, considering frequency domain inter-cell interference cancellation between neighboring cells, a portion of the spectrum in the middle of the total bandwidth can be excluded, and both BWPs can be set within the same slot. That is, the base station can configure at least one DL / UL BWP for a terminal associated with a wideband CC, and can activate at least one DL / UL BWP among the configured DL / UL BWP(s) at a specific point in time (by L1 signaling or MAC CE or RRC signaling, etc.), and switching to another configured DL / UL BWP can be indicated (by L1 signaling or MAC CE or RRC signaling, etc.), or switching to a predetermined DL / UL BWP when the timer value expires based on a timer. At this time, the activated DL / UL BWP is defined as the active DL / UL BWP. However, the terminal may not receive the configuration for the DL / UL BWP in situations such as when the terminal is in the initial access process or before the RRC connection is set up. In such situations, the DL / UL BWP assumed by the terminal is defined as the initial active DL / UL BWP.

[0071] FIG. 5 is a diagram for explaining physical channels that can be used in various embodiments and a signal transmission method using the same.

[0072] Referring to FIG. 5, a terminal that is powered on again after being powered off or that has newly entered a cell performs an initial cell search operation, such as synchronizing with the base station, in step S11. To this end, the terminal receives a Synchronization Signal Block (SSB) from the base station. The SSB includes a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). Based on the PSS / SSS, the terminal synchronizes with the base station and obtains information such as a cell ID (cell identity). In addition, the terminal can obtain broadcast information within the cell based on the PBCH. Meanwhile, the terminal can check the downlink channel status by receiving a Downlink Reference Signal (DL RS) during the initial cell search phase.

[0073] A terminal that has completed initial cell search can obtain more specific system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) based on physical downlink control channel information (S12).

[0074] Thereafter, the terminal may perform a random access procedure to complete connection to the base station (S13 to S16). To this end, the terminal may transmit a preamble through a physical random access channel (PRACH) (S13) and receive a random access response (RAR) for the preamble through a physical downlink control channel and a corresponding physical downlink shared channel (S14). The terminal may transmit a physical uplink shared channel (PUSCH) using scheduling information in the RAR (S15) and perform a contention resolution procedure such as receiving a physical downlink control channel signal and a corresponding physical downlink shared channel signal (S16).

[0075] Meanwhile, in addition to the random access process performed in 4 steps as above (4-step RACH, type-1 random access procedure), when the random access process is performed in 2 steps (2-step RACH, type-2 random access procedure), S13 / S15 may be performed as one operation in which the terminal performs transmission (e.g., transmission operation of message A including PRACH preamble and / or PUSCH), and S14 / S16 may be performed as one operation in which the base station performs transmission (e.g., transmission operation of message B including RAR and / or collision resolution information).

[0076] A terminal that has performed the procedure described above can then perform general uplink / downlink signal transmission procedures, such as receiving a physical downlink control channel signal and / or a physical downlink shared channel signal (S17) and transmitting a physical uplink shared channel (PUSCH: Physical Uplink Shared Channel) signal and / or a physical uplink control channel (PUCCH: Physical Uplink Control Channel) signal (S18).

[0077] Control information transmitted from a terminal to a base station is collectively referred to as uplink control information (UCI). UCI includes information such as HARQ-ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CQI (Channel Quality Indication), PMI (Precoding Matrix Indication), and RI (Rank Indication).

[0078] UCI is typically transmitted periodically over the PUCCH, but can also be transmitted over the PUSCH when control information and data must be transmitted simultaneously. Furthermore, terminals can transmit UCI aperiodically over the PUSCH at the request / instruction of the network.

[0079] Figure 6 illustrates a process in which a terminal transmits ACK / NACK via PUSCH.

[0080] Referring to FIG. 6, the terminal can detect a PDCCH in slot #n. Here, the PDCCH includes downlink scheduling information (e.g., DCI formats 1_0, 1_1), and the PDCCH indicates a DL assignment-to-PDSCH offset (K0) and a PDSCH-HARQ-ACK reporting offset (K1). For example, DCI formats 1_0, 1_1 can include the following information:

[0081] - Frequency domain resource assignment: Indicates the set of RBs allocated to the PDSCH.

[0082] - Time domain resource assignment: K0 (e.g., slot offset), indicates the starting position of the PDSCH within slot #n+K0 (e.g., OFDM symbol index), and the length of the PDSCH (e.g., number of OFDM symbols).

[0083] - PDSCH-to-HARQ_feedback timing indicator: Indicates K1

[0084] - HARQ process number (4 bits): Indicates the HARQ process ID (Identity) for data (e.g., PDSCH, TB)

[0085] - PUCCH resource indicator (PRI): Indicates the PUCCH resource to be used for UCI transmission among multiple PUCCH resources within the PUCCH resource set.

[0086] Afterwards, the terminal receives PDSCH from slot #(n+K0) according to the scheduling information of slot #n, and when reception of PDSCH is finished in slot #n1 (where, n+K0≤n1), UCI can be transmitted through PUCCH in slot #(n1+K1). Here, UCI may include HARQ-ACK response for PDSCH. In Fig. 6, for convenience, it is assumed that SCS for PDSCH and SCS for PUCCH are the same and slot# n1 = slot# n+K0, but the present invention is not limited thereto. If the SCSs are different, K1 can be indicated / interpreted based on the SCS of PUCCH.

[0087] When the PDSCH is configured to transmit at most 1 TB, the HARQ-ACK response may consist of 1 bit. When the PDSCH is configured to transmit at most 2 TB, the HARQ-ACK response may consist of 2 bits if spatial bundling is not configured, and may consist of 1 bit if spatial bundling is configured. When the HARQ-ACK transmission timing for multiple PDSCHs is designated as slot #(n+K1), the UCI transmitted in slot #(n+K1) includes HARQ-ACK responses for multiple PDSCHs.

[0088] Whether a UE should perform spatial bundling for a HARQ-ACK response can be configured (e.g., via RRC / higher layer signaling) for each cell group. For example, spatial bundling can be individually configured for each HARQ-ACK response transmitted over the PUCCH and / or each HARQ-ACK response transmitted over the PUSCH.

[0089] Spatial bundling can be supported when the maximum number of TBs (or codewords) that can be received at a time (or scheduled via 1 DCI) in the serving cell is 2 (or more than 2) (e.g., when the upper layer parameter maxNrofCodeWordsScheduledByDCI corresponds to 2-TB). Meanwhile, more than 4 layers can be used for 2-TB transmission, and up to 4 layers can be used for 1-TB transmission. Consequently, when spatial bundling is configured for the cell group, spatial bundling can be performed for serving cells that can schedule more than 4 layers among the serving cells in the cell group. On the serving cell, a UE that wishes to transmit a HARQ-ACK response via spatial bundling can generate the HARQ-ACK response by performing a (bit-wise) logical AND operation on the A / N bits for multiple TBs.

[0090] For example, assuming that a terminal receives a DCI scheduling 2 TB and receives 2 TB via PDSCH based on the DCI, the terminal performing spatial bundling can generate a single A / N bit by logically ANDing the first A / N bit for the first TB and the second A / N bit for the second TB. Consequently, if both the first TB and the second TB are ACK, the terminal reports the ACK bit value to the base station, and if either TB is NACK, the terminal reports the NACK bit value to the base station.

[0091] For example, if only 1-TB is actually scheduled on a serving cell configured to receive 2-TB, the terminal can generate a single A / N bit by logically ANDing the A / N bit for the 1-TB with bit value 1. Consequently, the terminal reports the A / N bit for the 1-TB to the base station as is.

[0092] A base station / terminal has multiple parallel DL HARQ processes for DL ​​transmission. These multiple parallel HARQ processes allow DL transmissions to be performed continuously while waiting for HARQ feedback regarding the success or failure of the previous DL transmission. Each HARQ process is associated with a HARQ buffer in the MAC (Medium Access Control) layer. Each DL HARQ process manages state variables such as the number of transmissions of MAC Physical Data Blocks (PDUs) in the buffer, HARQ feedback for MAC PDUs in the buffer, and the current redundancy version. Each HARQ process is identified by a HARQ process ID.

[0093] Below, the PUSCH transmission process is described.

[0094] The terminal can detect the PDCCH in slot #n. Here, the PDCCH includes uplink scheduling information (e.g., DCI formats 0_0 and 0_1). DCI formats 0_0 and 0_1 can include the following information.

[0095] - Frequency domain resource assignment: Indicates the set of RBs allocated to PUSCH.

[0096] - Time domain resource assignment: Slot offset K2 indicates the starting position (e.g., symbol index) and length (e.g., number of OFDM symbols) of the PUSCH within the slot. The starting symbol and length can be indicated through SLIV (Start and Length Indicator Value) or can be indicated separately.

[0097] Thereafter, the terminal can transmit a PUSCH in slot #(n+K2) according to the scheduling information of slot #n. Here, the PUSCH includes a UL-SCH TB.

[0098] CSI-related actions

[0099] Figure 7 shows an example of a CSI-related procedure.

[0100] The terminal receives configuration information related to CSI from the base station via RRC signaling (710). The configuration information related to CSI may include at least one of CSI-IM (interference management) resource-related information, CSI measurement configuration-related information, CSI resource configuration-related information, CSI-RS resource-related information, or CSI report configuration-related information.

[0101] - CSI-IM resources can be configured for interference measurement (IM) of the terminal. In the time domain, the CSI-IM resource set can be configured periodically, semi-persistently, or aperiodicly. The CSI-IM resources can be configured as Zero Power (ZP)-CSI-RS for the terminal. The ZP-CSI-RS can be configured separately from the Non-Zero Power (NZP)-CSI-RS.

[0102] - The UE may assume that the CSI-RS resource(s) for channel measurement configured for one CSI reporting and the CSI-IM / NZP CSI-RS resource(s) for interference measurement (when NZP CSI-RS resource(s) are used for interference measurement) are in a QCL relationship with respect to 'QCL-TypeD' per resource.

[0103] - The CSI resource configuration may include at least one of a CSI-IM resource for interference measurement, an NZP CSI-RS resource for interference measurement, and an NZP CSI-RS resource for channel measurement. The CMR (channel measurement resource) may be an NZP CSI-RS for CSI acquisition, and the IMR (Interference measurement resource) may be an NZP CSI-RS for CSI-IM and IM.

[0104] - CSI-RS can be configured for one or more terminals. Different CSI-RS configurations may be provided for each terminal, or the same CSI-RS configuration may be provided to multiple terminals. CSI-RS can support up to 32 antenna ports. CSI-RS corresponding to N (N is 1 or greater) antenna ports can be mapped to N RE locations within a time-frequency unit corresponding to one slot and one RB. When N is 2 or greater, N-port CSI-RS can be multiplexed using CDM, FDM, and / or TDM schemes. CSI-RS can be mapped to REs other than REs to which CORESET, DMRS, and SSB are mapped. In the frequency domain, CSI-RS can be configured for the entire bandwidth, a portion of the bandwidth (BWP), or a portion of the bandwidth. CSI-RS may be transmitted in each RB within the bandwidth for which CSI-RS is configured (i.e., density = 1), or in every second RB (e.g., even or odd RB) (i.e., density = 1 / 2). When CSI-RS is used as a Tracking Reference Signal (TRS), a single-port CSI-RS may be mapped on three subcarriers in each resource block (i.e., density = 3). One or more CSI-RS resource sets may be configured for a UE in the time domain. Each CSI-RS resource set may include one or more CSI-RS configurations. Each CSI-RS resource set may be configured periodically, semi-persistently, or aperiodicly.

[0105] - The CSI report configuration may include configurations for feedback type, measurement resources, report type, etc. The NZP-CSI-RS resource set may be used for the CSI report configuration of the corresponding terminal. The NZP-CSI-RS resource set may be associated with CSI-RS or SSB. In addition, multiple periodic NZP-CSI-RS resource sets may be configured as TRS resource sets. (i) The feedback type may include a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), a CSI-RS Resource Indicator (CRI), an SSB Resource block Indicator (SSBRI), a Layer Indicator (LI), a Rank Indicator (RI), a Layer 1-Reference Signal Received Strength (RSRP), etc. (ii) Measurement resources may include configurations for downlink signals and / or downlink resources on which the terminal performs measurements to determine feedback information. The measurement resources may be configured as ZP and / or NZP CSI-RS resource sets associated with CSI reporting configurations. The NZP CSI-RS resource set may include a CSI-RS set or an SSB set. For example, L1-RSRP may be measured for a CSI-RS set or an SSB set. (iii) Reporting types may include configurations for a time point at which the terminal performs reporting and an uplink channel, etc. The reporting time point may be configured as periodic, semi-persistent, or aperiodic. Periodic CSI reporting may be transmitted on PUCCH. Semi-persistent CSI reporting may be transmitted on PUCCH or PUSCH based on a MAC CE indicating activation / deactivation. Aperiodic CSI reporting may be indicated by DCI signaling.For example, the CSI request field of an uplink grant may indicate one of several report trigger sizes. Aperiodic CSI reports may be transmitted on the PUSCH.

[0106] The terminal measures CSI based on configuration information related to CSI. CSI measurement may include a procedure of receiving a CSI-RS (720) and computing the received CSI-RS to acquire CSI (730).

[0107] The UE can transmit a CSI report to the base station (740). For the CSI report, the time and frequency resources that the UE can use are controlled by the base station. The CSI (channel state information) can include at least one of a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), an SS / PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), L1-RSRP, and / or L-SINR.

[0108] The time domain operation of CSI reporting supports periodic, semi-persistent, and aperiodic operations. i) Periodic CSI reporting is performed on short PUCCH and long PUCCH. The periodicity and slot offset of periodic CSI reporting can be configured by RRC, and refer to the CSI-ReportConfig IE. ii) Semi-periodic (SP) CSI reporting is performed on short PUCCH, long PUCCH, or PUSCH. In case of SP CSI on short / long PUCCH, the periodicity and slot offset are configured by RRC, and CSI reporting is activated / deactivated by separate MAC CE / DCI. In case of SP CSI on PUSCH, the periodicity of SP CSI reporting is set to RRC, but the slot offset is not set to RRC, and SP CSI reporting is activated / deactivated by DCI (format 0_1). A separate RNTI (SP-CSI C-RNTI) is used for SP CSI reporting on PUSCH. The timing of the first CSI report follows the PUSCH time domain allocation value indicated in the DCI, and the timing of subsequent CSI reports follows the period set by RRC. DCI format 0_1 ​​includes a CSI request field and can activate / deactivate a specific configured SP-CSI trigger state. SP CSI reporting has the same or similar activation / deactivation mechanism as that of data transmission on SPS PUSCH.iii) Aperiodic CSI reporting is performed on PUSCH and is triggered by DCI. In this case, information related to the trigger of aperiodic CSI reporting can be transmitted / indicated / configured via MAC-CE. For AP CSI with AP CSI-RS, the AP CSI-RS timing is configured by RRC, and the timing for AP CSI reporting is dynamically controlled by DCI.

[0109] CSI codebooks defined in the NR standard (e.g., PMI codebooks) can be broadly divided into Type I and Type II codebooks. Type I codebooks are primarily targeted at SU (Single User)-MIMO, which supports both high-order and low-order signals. Type II codebooks can primarily support MI-MIMO, which supports up to two layers. Compared to Type I, Type II codebooks can provide more accurate CSI, but may increase signaling overhead. Meanwhile, Enhanced Type II codebooks were introduced to address the CSI overhead shortcomings of existing Type II codebooks. Enhanced Type II codebooks were introduced by reducing the codebook payload by considering frequency-axis correlation.

[0110] CSI reporting via PUSCH can be configured as Part 1 and Part 2. Part 1 has a fixed payload size and is used to identify the number of information bits in Part 2. Part 1 is transmitted in its entirety before Part 2.

[0111] - For Type I CSI feedback, Part 1 contains the RI (if reported), the CRI (if reported), and the CQI of the first code word. Part 2 contains the PMI, and when RI > 4, Part 2 contains the CQI.

[0112] - For Type II CSI feedback, Part 1 contains the RI (if reported), CQI, and an indication of the number of non-zero WB amplitude coefficients per layer of Type II CSI. Part 2 contains the PMI of Type II CSI.

[0113] - For Enhanced Type II CSI feedback, Part 1 contains the RI (if reported), CQI, and the total number of non-zero WB amplitude coefficients for all layers of Enhanced Type II CSI. Part 2 contains the PMI of Enhanced Type II CSI.

[0114] If a CSI report on PUSCH includes two parts and the CSI payload to be reported is less than the payload size provided by the PUSCH resources allocated for CSI reporting, the UE may omit part of Part 2 CSI.

[0115] Meanwhile, semi-persistent CSI reporting performed in PUCCH format 3 or 4 supports Type II CSI feedback, but only Part 1 of Type II CSI feedback.

[0116] For CSI reporting, the time and frequency resources available to the UE are controlled by the base station.

[0117] CSI (channel state information) may include at least one of a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), an SS / PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), L1-RSRP, and / or L-SINR.

[0118] For CQI, PMI, CRI, SSBRI, LI, RI, and L1-RSRP, the UE is configured by a higher layer with N≥1 CSI-ReportConfig reporting settings, M≥1 CSI-ResourceConfig resource settings, and a list of one or two trigger states (provided by CSI-AperiodicTriggerStateList and CSI-SemiPersistentOnPUSCH-TriggerStateList). Each trigger state in the CSI-AperiodicTriggerStateList includes an associated list of CSI-ReportConfigs indicating resource set IDs for channel and optionally interference. Each trigger state in the CSI-SemiPersistentOnPUSCH-TriggerStateList includes one associated CSI-ReportConfig.

[0119] Additionally, the time domain behavior of CSI reporting supports periodic, semi-persistent, and aperiodic.

[0120] i) Periodic CSI reporting is performed on short PUCCH and long PUCCH. The periodicity and slot offset of periodic CSI reporting can be configured via RRC, and refer to the CSI-ReportConfig IE.

[0121] ii) SP (semi-periodic) CSI reporting is performed on short PUCCH, long PUCCH, or PUSCH.

[0122] In case of SP CSI on short / long PUCCH, the period and slot offset are set by RRC, and CSI reporting is activated / deactivated with a separate MAC CE / DCI.

[0123] In the case of SP CSI on PUSCH, the periodicity of SP CSI reporting is set to RRC, but the slot offset is not set to RRC, and SP CSI reporting is activated / deactivated by DCI (format 0_1). For SP CSI reporting on PUSCH, a separate RNTI (SP-CSI C-RNTI) is used.

[0124] The initial CSI reporting timing follows the PUSCH time domain allocation value indicated in the DCI, and subsequent CSI reporting timing follows the cycle set by RRC.

[0125] DCI format 0_1 ​​contains a CSI request field and can activate / deactivate a specific configured SP-CSI trigger state. SP CSI reporting has the same or similar activation / deactivation mechanism as data transmission on the SPS PUSCH.

[0126] iii) Aperiodic CSI reporting is performed on PUSCH and is triggered by DCI. In this case, information related to the triggering of aperiodic CSI reporting can be transmitted / indicated / configured via MAC-CE.

[0127] For AP CSI with AP CSI-RS, AP CSI-RS timing is set by RRC, and timing for AP CSI reporting is dynamically controlled by DCI.

[0128] NR does not apply the method of dividing CSI into multiple reporting instances (e.g., transmitting in the order of RI, WB PMI / CQI, and SB PMI / CQI) used for PUCCH-based CSI reporting in LTE. Instead, NR restricts specific CSI reporting on short / long PUCCHs and defines CSI omission rules. Furthermore, with respect to AP CSI reporting timing, PUSCH symbol / slot locations are dynamically indicated by DCI. Candidate slot offsets are configured by RRC. For CSI reporting, the slot offset (Y) is configured for each reporting setting. For UL-SCH, the slot offset K2 is configured separately.

[0129] Two CSI latency classes (low latency class, high latency class) are defined from the perspective of CSI computation complexity. Low latency CSI is WB CSI including up to 4 ports Type-I codebook or up to 4-port non-PMI feedback CSI. High latency CSI refers to any CSI other than low latency CSI. For a normal terminal, (Z, Z') is defined in units of OFDM symbols. Here, Z represents the minimum CSI processing time from receiving an aperiodic CSI triggering DCI to performing a CSI report. In addition, Z' represents the minimum CSI processing time from receiving a CSI-RS for channel / interference to performing a CSI report.

[0130] Additionally, the terminal reports the number of CSIs it can calculate simultaneously.

[0131] QCL (quasi-co location)

[0132] Two antenna ports are quasi-co-located if the channel properties of one antenna port can be inferred from the channel properties of the other antenna port. The channel properties may include one or more of Delay spread, Doppler spread, Frequency / Doppler shift, Average received power, Received Timing / average delay, and Spatial RX parameters.

[0133] A terminal can configure a list of multiple TCI-State configurations via the upper layer parameter PDSCH-Config. Each TCI-State is associated with one or two DL reference signals and a QCL configuration parameter between the DM-RS port of the PDSCH. The QCL can include qcl-Type1 for the first DL RS and qcl-Type2 for the second DL RS. The QCL type can correspond to one of the following:

[0134] - 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

[0135] - 'QCL-TypeB': {Doppler shift, Doppler spread}

[0136] - 'QCL-TypeC': {Doppler shift, average delay}

[0137] - 'QCL-TypeD': {Spatial Rx parameter}

[0138] Beam Management (BM)

[0139] The BM process is a process for acquiring and maintaining a set of BS (or transmission and reception point (TRP)) and / or UE beams that can be used for downlink (DL) and uplink (UL) transmission / reception, and may include the following processes and terms.

[0140] - Beam measurement: An operation in which a BS or UE measures the characteristics of a received beamforming signal.

[0141] - Beam determination: An operation in which a BS or UE selects its own transmit beam (Tx beam) / receive beam (Rx beam).

[0142] - Beam sweeping: An operation of covering a spatial domain using transmit and / or receive beams over a predetermined time interval in a predetermined manner.

[0143] - Beam report: An operation in which a UE reports information about a beamformed signal based on beam measurement.

[0144] The BM process can be divided into (1) a DL BM process using SSB or CSI-RS, and (2) a UL BM process using SRS (sounding reference signal). In addition, each BM process can include Tx beam sweeping to determine a Tx beam and Rx beam sweeping to determine an Rx beam.

[0145] At this time, the DL BM process may include (1) transmission of beamformed DL RSs (e.g., CSI-RS or SSB) by the BS and (2) beam reporting by the UE.

[0146] Here, the beam report may include preferred DL RS ID(s) and corresponding reference signal received power (RSRP). The DL RS ID may be an SSB Resource Indicator (SSBRI) or a CSI-RS Resource Indicator (CRI).

[0147] Figure 8 illustrates an example of an LTM procedure.

[0148] Referring to FIG. 8, a terminal (UE) transmits a Measurement Report message to a base station (gNB). The base station determines an LTM setting and initiates an LTM preparation procedure (501).

[0149] The base station transmits an RRCReconfiguration message including an LTM candidate configuration to the terminal (502).

[0150] The terminal stores the LTM candidate configuration and transmits an RRCReconfigurationComplete message to the base station (503).

[0151] The terminal performs downlink synchronization (DL synchronization) with LTM candidate cells before receiving a cell switch command. The terminal can activate or deactivate the TCI state of the LTM candidate cells according to a trigger from the base station (504a).

[0152] The UE can perform uplink synchronization (UL synchronization) with LTM candidate cells before receiving a cell switch command, either through UE-based TA measurement or preamble transmission according to a base station trigger, if configured. If UE-based TA measurement is configured, the UE acquires TA values ​​for candidate cells through measurement (504b). If requested by the network, the UE performs pre-TA acquisition with the candidate cells. In this case, a CFRA is triggered by a PDCCH command from the source cell, and the UE transmits a preamble to the indicated candidate cell. To minimize data interruption of the source cell due to CFRA for candidate cells, the UE does not receive a random access response from the network for the purpose of TA value acquisition, and the TA value of the candidate cell is specified in the cell switch command. The UE does not maintain a TA timer for the candidate cell, and TA validity guarantee depends on the network implementation.

[0153] The terminal performs L1 measurements on the configured LTM candidate cells and transmits the corresponding L1 measurement report to the base station (505). The L1 measurements must be performed while the RRC reconfiguration (502) is valid.

[0154] The base station determines a cell switch to the target cell and transmits an LTM cell switch command MAC CE (506) that triggers the cell switch. This command includes a target configuration ID indicating a candidate configuration index of the target cell, a beam indicated by a TCI state or multiple beams indicated by a DL / UL TCI state, and, if available, a TA command for the target cell. The terminal switches to the target cell according to the indicated target configuration ID and applies the candidate configuration.

[0155] If the terminal does not have a valid TA value for the target cell, the terminal performs a random access procedure for the target cell (507).

[0156] The UE completes the LTM cell switch procedure by sending an RRCReconfigurationComplete message to the target cell (508). If the UE performed a random access procedure in step 507, the LTM cell switch is considered to have been successfully completed when the random access procedure is successfully completed. In the case of RACH-less LTM, the UE considers the LTM cell switch to have been completed when it determines that the first UL data has been successfully received by the network.

[0157] Steps 504 to 508 can be performed iteratively by utilizing the LTM candidate configuration provided in step 502.

[0158] The procedure on the wireless interface illustrated in Fig. 8 can be applied to both intra-BS-DU LTM and inter-BS-DU LTM.

[0159] For LTM and L1 measurement reporting, 1) LTM-CSI-ResourceConfig information element and 2) LTM-CSI-ReportConfig information element may be provided to the terminal through upper layer signaling.

[0160] 1) The LTM-CSI-ResourceConfig information element may be configured to define one or more CSI resource groups related to one or more LTM candidate configurations. LTM-CSI-ResourceConfig may include ltm-CSI-ResourceConfigId-r18 and ltm-CSI-SSB-ResourceSet-r18. ltm-CSI-SSB-ResourceSet-r18 is a set including multiple SS / PBCH block resources and associated LTM candidate identifiers, including the following items:

[0161] ltm-CSI-SSB-ResourceList-r18: An index list identifying one or more SS / PBCH block resources, which may be configured across different LTM candidate cells.

[0162] ltm-CandidateIdList-r18: A list of LTM candidate cell IDs corresponding to each SSB resource. The first candidate cell ID is associated with the first SSB index, the second candidate cell ID is associated with the second SSB index, and so on.

[0163] 2) LTM-CSI-ReportConfig is an information element for configuring an LTM-related CSI-based measurement report performed for a specific cell, and the reporting target cell is defined as a cell that includes the LTM-CSI-ReportConfig.

[0164] LTM-CSI-ReportConfig may contain: (i) ltm-CSI-ReportConfigId-r18, (ii) ltm-ResourcesForChannelMeasurement-r18 (representing reference CSI resource configuration for measurements, identified by LTM-CSI-ResourceConfigId), (iii) ltm-ReportConfigType-r18 (periodic / semiPersistentOnPUCCH / semiPersistentOnPUSCH / aperiodic), (iv) ltm-ReportContent-r18

[0165] ltm-ReportContent-r18 defines what will be included in a single L1 measurement report instance and can include the following parameters:

[0166] - nrOfReportedCells-r18: Number of cells reported (e.g. 1 to 4)

[0167] - nrOfReportedRS-PerCell-r18: Number of RS reported per cell (e.g. 1 to 4)

[0168] - spCellInclusion-r18: Defines whether to include the current serving cell (SpCell) in the report. Configurable only when SpCell is set as an LTM candidate.

[0169] Meanwhile, with regard to the above-described LTM procedure, reinforcement measures such as those in Tables 5 and 6 below are being discussed.

[0170] Enhancements for L1 Inter-Cell Beam Management (ICBM) (1) L1 Measurements for ICBM1) Measurement Resources- L1 intra- / inter-frequency measurements- CD-SSB-- SSB periodicity, position of SSB within burst are provided as time domain information for both intra-cell and inter-cell frequencies-- In terms of configuration, PCI is associated with SSB within LTM-CSI-SSB-ResourceSet: ① For serving cell, it is provided within ServingCellConfig ② For candidate cell, it is provided within CellGroupConfig, separate from ServingCellConfig of serving cell2) Beam Direction- Beam direction for candidate cell in Rel-18 LTM is designed based on Rel-17 Unified TCI Framework-- For more than one candidate cell, TCI state activation via MAC CE is allowed before cell switching command.- For TCI state configuration:-- Within QCL-Info of each TCI state, maximum 2 QCL types and each QCL type source RS is based on RS configuration for LTM Provided: ① In Rel-18 LTM, provided as a QCL source in TCI state before / during cell switch command ② For candidate cells, SSB or TRS can be configured in TCI state before / during cell switch command.(2) L1 Measurement Report1) Report as UCI - Periodic PUCCH, Semi-persistent PUCCH / PUSCH, Aperiodic PUSCH2) Report quantity: L1-RSRP3) Within one reporting instance, reports on serving cell and candidate cells (including intra-cell frequencies and / or inter-cell frequencies) can be included - Among the configured L cells, M beams can be selected for each cell (the maximum M / L is determined by the UE performance) (e.g., M×L beams are reported within one reporting instance) - SSBRI between the configured candidate cells is included in each L1-RSRP report - The bit size of SSBRI is log2(K_SSB), where K_SSB is the number of SSBs configured in the resource set for the corresponding report4) With CSI report - LTM CSI report processing occupies 1 CPU - According to the priority rule of CSI report, LTM CSI report has priority over the existing CSI report. (3) Cell switch command (CSC) via MAC-CE1) Information items that may be included in the CSC (at a minimum): - Information to identify the target cell - Timing Advance (TA) related information - Active DL / UL BWP for the target cell - One unified or UL / DL unified TCI state index pair for the target cell - Beam indication for the target cell and TCI state activation for the candidate cell are performed via Rel-17 TCI state index indication - After the RACH procedure, the UE follows the TCI state indicated in the cell switch command until a new TCI state is indicated by the target cell (at least for CFRA triggered by the cell switch command) - Beam application timing is supported, which starts after the last symbol of the PUCCH or PUSCH carrying the HARQ-ACK for the PDSCH containing the MAC-CE.

[0171] Timing Advance (TA) Management for Delay Reduction (1) Mechanism for TA Acquisition of Candidate Cell (PDCCH-based RACH) 1) PDCCH ordered RACH (CBRA, CFRA) - PDCCH order from source cell contains information indicating candidate cell. -- Reserved bits in DCI format 1_0 for PDCCH command can be used to indicate cell identity. -- The size of N bits in DCI format 1_0 for cell indication is determined by the number of candidate cells (C) for which RACH configuration for early TA acquisition is provided: ① N = ceil (log₂(C + 1)) ② The number of cells for bit calculation is the number of candidate cells for which RACH configuration for early TA acquisition is provided + 1 (including the serving cell) - PDCCH command is triggered only by the source cell2) RACH-less mechanism - UE-based TA measurement (UE derives TA based on the reception timing difference between the current serving cell and candidate cells and the TA value of the serving cell) is supported.-- UE capability to support UE-based TA measurement is introduced-- UE-based TA measurement configuration is supported if the UE reports support for the corresponding capability (2) RACH for TA acquisition1) Configuration - RACH resources for candidate cells Configuration is provided prior to the PDCCH command - For Rel-18 LTM, RACH occasion information is configured along with the SSB index associated with the random access preamble index for each candidate cell. 2) Transmit power - The SSB of the candidate cell indicated by the PDCCH command is used as the path loss reference RS for PRACH transmit power estimation - If RAR is not configured: -- Explicitly indicates whether the PRACH is an initial transmission or a retransmission via a 1-bit field in the PDCCH command -- Whether power ramping is performed is determined by the PDCCH command: If power ramping is performed, a power increase value is configured.Otherwise, power is determined by open loop power control. - For CFRA, - UE maintains only one power ramping counter. - Upon receiving a PDCCH command indicating initial transmission of PRACH, the power ramping counter is reset. - Upon receiving a PDCCH command indicating retransmission of PRACH for the same candidate cell and the same SSB, the counter is incremented by 1. - The power ramping counter is reset when: The candidate cell in the PDCCH command indicating retransmission is different from the one in the previous PDCCH command.3) RAR - Whether RAR is received is configured by RRC. - If RAR reception is configured: - If RAR is received from the serving cell (including both intra- / inter-DU situations) - If RAR includes at least TAs of candidate cells: ① UE stores (remembers / maintains / processes) TAs for at least one candidate cell. ② The maximum number of TAs that the UE can store is determined by UE capabilities. - If RAR reception is not configured, regardless of the PreambleTransMax setting, the UE PRACH autonomous retransmission.4) Simultaneous / parallel transmission- In case of PDCCH command-based PRACH transmission for a candidate cell, if the UE capability does not support simultaneous / parallel transmission, if the PRACH transmission (or the delay time for preparing the transmission, carrier / BWP switching time, UL / DL RF tuning time, etc.) overlaps with a subsequent UL transmission for the serving cell by one or more symbols, or if the time interval between the two transmissions is shorter than a certain threshold (N symbols), the UL transmission for the serving cell is aborted-- PRACH transmission-- PUCCH / PUSCH transmission including HARQ-ACK, SR, P / SP CSI, aperiodic CSI-- SRS transmission-- Any other PUCCH / PUSCH transmission- If the UE supports simultaneous / parallel transmission:-- PRACH transmission for the LTM candidate cell has the highest priority in terms of power allocation.(3) TA update for candidate cells can be triggered by the network 1) RACH execution within candidate cells based on PDCCH command (reuse of initial TA acquisition method).

[0172] Meanwhile, the method of event-triggered reporting in Rel-18 mobility enhancement was discussed but not introduced and was included in the WID of R19. The following are the matters discussed as the method of event-triggered reporting in Rel-18 mobility enhancement. Among the existing L3 events, A2 and A4 (simple comparison with the set threshold) were deleted, and A3 and A5 (compare between candidate cells / serving cells) were discussed as candidates. Regarding the method of transmitting the event-triggered report, the method / structure in which the UE transmits the event-triggered report to the MAC-CE within the RRC-set time duration (time to trigger) was discussed. However, RAN2 did not discuss mobility-related events or event-triggered reporting.

[0173] Specifically, while existing RRM (Radio Resource Management) reporting supports periodic reporting and event triggered reporting based on cell quality, it has been agreed to support Layer 1 (L1) signaling for LTM (L1 / L2 triggered mobility, or Layer Two Mobility). Mobility enhancement up to Rel-18 has been performed based on SSB. For example, it is supported that the UE performs beam reporting for the target cell to which it will hand over, and the beam reporting can be performed with Layer 1 signaling. In this regard, in Rel-19, operations related to mobility enhancement, such as the LTM procedure, have been extended to be based on CSI-RS. In addition, the introduction of event triggered reporting has been discussed in Rel-19. Event triggered reporting may mean that the UE performs reporting by triggering a specific reporting configuration by the gNB, but rather, the UE directly determines that the event is triggered based on a configured event and performs reporting without scheduling by the gNB when the event is triggered. In this case, signaling overhead is reduced, and it can be effective in reducing latency because separate scheduling is not required after an event occurs. Currently, event-triggered reporting for mobility has not been defined in NR, so discussion may be needed to introduce a method for event-triggered reporting for mobility.

[0174] In this regard, the most similar operation, UE-initiated beam reporting, has been discussed in Rel-19 MIMO (Multiple-Input Multiple-Output), and standardization of the discussed matters is in progress. The discussion of UE-initiated beam reporting in Rel-19 MIMO is as follows. Only a simple comparison against a configured threshold (A2, A4 in terms of existing L3 events) is defined as an event, and multiple events are not defined. Whether an event trigger is satisfied can be determined based on the number of times the configured threshold is exceeded (regardless of consistent / non-consecutive) within a given time window. The UE reports the event trigger to the gNB via PUCCH, and depending on the mode, it can report the event trigger report via UCI. The discussed matters (e.g., RAN1 agreements) related to this are as shown in Tables 7, 8, and 9 below.

[0175] The following modes are supported in the beam report transmission procedure for UE-initiated / event-based beam reporting: (1) Mode A (dynamic scheduling of UCI by gNB):> Step 1: The UE transmits a first PUCCH (1 bit or multiple bits) to request resources for a second uplink channel on which to transmit the beam report - FFS: request format, e.g. SR or a new UCI type.> Step 2: The UE detects a DCI format indicating resources for the second uplink channel on which to transmit the beam report.> Step 3: The beam report is transmitted on the second uplink channel. - FFS: details of the second uplink channel, e.g. whether the second uplink channel is PUCCH, PUSCH or both.> This option is a basic UE capability (i.e. all UEs supporting UE-initiated / event-based beam reporting must support this capability).> No new DCI formats are introduced. (2) Mode B (using UCI on pre-configured resources for the second uplink channel):> Step 1: The UE transmits a first PUCCH (1 bit or multiple bits) to request resources for a second uplink channel on which to transmit the beam report. Transmit the first PUCCH (1 bit or multiple bits) to announce the uplink channel - FFS: Announcement format, e.g. SR or new UCI type.> Step 2: The UE transmits a beam report on the second uplink channel - FFS: Details of the second uplink channel, e.g. whether the second uplink channel is PUCCH, PUSCH or both.> The announcement in Step 1 is a separate reporting instance from the beam report in Step 2.

[0176] (1) In UE-initiated / event-based beam reporting, with respect to trigger event detection for beam reporting, at least Event-2: Supports the case where the quality (e.g., L1-RSRP) of one or more new beams is improved by a threshold value or more than that of the current beam. > At least L1-RSRP is supported as a quality metric used for Event-2. - FFS: How L1-RSRP is used to determine triggering events (e.g., timers, counters, filter coefficients). - FFS: Whether the network controls how L1-RSRP is used (how triggering events are determined). > With respect to RS measurement of new beam for Event-2, one or more of the following is optionally applied: - Option-3a (Explicit): RS for new beam is explicitly configured by RRC (e.g., reuse of existing RS measurement configuration or configuration in TCI-State) or MAC-CE. - Option-3b (Implicit): RS for new beam is implicitly derived from QCL RS of activated TCI-State. - Option-3c (Implicit): RS for new beam is not configured. > Implicitly derived from the QCL RS of the indicated TCI state. > Note-1: The term 'new / current beam' is for discussion purposes only. > Note-2: Other trigger events / quality metrics (e.g. L1-SINR) are not excluded. > Note-3: In the above implicit scheme, if two QCL RSs exist in one TCI state, the measured RS is derived from the RS corresponding to QCL-TypeD, if available. (2) In UE initiated / event based beam reporting, with respect to Event-2, the 'current beam' is the beam corresponding to the indicated TCI state. > With respect to RS measurement of the current beam for Event-2, Option-2a is supported:- Option-2a (Implicit scheme): The RS for the current beam is implicitly derived from the QCL RS of the indicated TCI state.-- FFS: The RS for the current beam can be either the QCL RS of the indicated TCI state or an SSB QCLed with that QCL RS.- FFS: Option-2c (Explicit): RS for current beam is explicitly configured by RRC or MAC-CE.-- Note: SSB or CSI-RS may be configured (3) In UE-initiated / event-based beam reporting, with respect to the uplink signaling content of L1-RSRP reporting according to Event-2, at least Option-3 is supported in one reporting instance> Option-3: N ≥ 1 beams are reported in one reporting instance-- At least one of the N reported beams must satisfy the Event-2 condition-- N is configured by gNB-- FFS: Candidate values ​​for 'N'.> FFS: RRC may allow / disallow the current beam to always be reported in addition to the N beams> FFS: Option-1 / 1a / 1b / 2.> The above applies at least in the single CC case (4) With respect to trigger event judgment for Event-2:> If, within a configurable time window, the number of Event-2 instances for the same new beam is greater than or equal to a configurable value M, then UE-initiated beam reporting is triggered. Occurs. - Note: An Event-2 instance for a new beam is determined when the L1-RSRP of the beam improves by more than a threshold value compared to the current beam (5) The above functionality depends on whether the UE supports the functionality. > Basic functionality: When the L1-RSRP of the new beam improves by more than a threshold value compared to the current beam, a UE-initiated beam report occurs (6) FFS: Whether the above is included in the RAN1 or RAN2 specification.

[0177] (1) Event-Triggered Reporting for Mobility: Discussions have been held regarding event-triggered reporting for mobility and beam reporting. Since these two items are evolving independently, WID has stated that RAN#105 will review their progress to determine if any modifications are necessary. This requires a detailed understanding of what has been discussed so far, which is discussed in Section 3.1. Building on this, details on event-triggered reporting for mobility are discussed in the following section. (2) Event-Triggered Reporting for MIMO and Mobility: This section briefly reviews event-triggered reporting for MIMO and mobility to provide information that will help determine how event-triggered reporting will be defined in Rel-19. In Rel-19 MIMO, event-triggered reporting was discussed under the name UE-initiated beam reporting. In summary, the reporting will be signaled via UCI, and the event definitions and triggering mechanisms have been determined. While not yet fully finalized, the basic functionality and signaling architecture are well-defined. On the other hand, event-triggered reporting was discussed in Rel-18 mobility enhancements, but no conclusion was reached. It was based on MAC-CE signaling, and only basic assumptions were discussed. Details on this are reviewed in this section. (3) Discussion on event-triggered reporting in Rel-18 mobility enhancements: While there was no clear conclusion or agreement on event-triggered reporting, it is clear that there were discussions on the topic. In terms of event definitions, there were proposals to consider A3 events (the quality of the neighboring cell improves by a certain offset compared to the PCell / PSCell) and A5 events (the quality of the PCell / PSCell worsens below an absolute threshold 1, and the quality of the neighboring cell / secondary cell improves above an absolute threshold 2) as baselines.Although the triggering mechanism has not been discussed, it has been proposed to signal via MAC-CE and for the UE to report event triggered reporting within a time period (event trigger duration) configured in RRC.> Observation x. The event triggered reporting discussed in Rel-18 mobility has the following assumptions: - Events are not defined, but A3 / A5 events are the baseline - Reported via MAC-CE (4) UE initiated beam reporting in MIMO UE initiated beam reporting is being discussed in Rel-19 MIMO. However, the basic structure is well defined and the UE behavior is revealed. Two modes are supported, but the basic UE functionality is that the UE transmits the first PUCCH to request resources of the second uplink channel. This means that the UE reports that an event is triggered, but the subsequent reporting is scheduled by the gNB. That is, the event trigger indication (and subsequent reporting) is signaled via UCI. Several events and their definitions have been considered, but only one has been agreed upon at this stage, Event-2, which is defined as “when the quality (e.g. L1-RSRP) of one or more new beams improves by a threshold value compared to the current beam”. In this event, it has been agreed that the ‘new beam’ is explicitly established via RRC signalling or MAC-CE, while the ‘current beam’ is defined as implicitly derived from the indicated TCI state. There is a configurable time window for determining a trigger event, and the event is considered triggered if the number of event instances for a particular new beam within this window exceeds a configured threshold value.> Observation: Event-triggered reporting (or UE-initiated beam reporting) in Rel-19 MIMO has the following characteristics: - Event definition: The quality of one or more explicitly configured new beams has improved by a threshold value compared to the implicitly derived current beams - Trigger event determination criteria: When the number of event instances for the same new beam exceeds a predefined number - Reported via UCI As such, two approaches for event-triggered reporting in different items are summarized. Both approaches are valid, but the choice of which one to adopt is necessary. The main purpose of event-triggered reporting is to reduce unnecessary signaling by enabling the UE to perform timely and meaningful reporting. However, this can also lead to network interference due to unscheduled transmissions from the UE, or excessive blind decoding or monitoring burden on the gNB due to uncertainty in the UE transmissions. Considering these points, it is a safe choice to introduce event-triggered reporting by leveraging the already defined framework. Furthermore, since LTM CSI reporting is based on a UCI-based beam reporting framework, it is desirable to consider MIMO-based UCI-based event-triggered reporting as a starting point. This also helps simplify the design without repeating already established discussions. > Proposal: For design simplicity and integration, the Rel-19 UE-initiated / event-based beam management framework is considered as a baseline for event-triggered reporting for improved mobility.

[0178] Below, we describe in detail event-triggered reporting in LTM for mobility, assuming that LTM CSI reporting is introduced as a signaling method to measure and report resources for candidate cells as layer 1 (L1) reporting, based on the above-described content.

[0179] Event triggered report for LTM

[0180] The definition of an event in enhanced mobility, or the definition of an event-triggered report, may be a definition of a report initiated by the UE without prior agreement or consent from the gNB for use in making a handover decision. Therefore, considering that the gNB will perform the handover decision in the definition of an event or event-triggered report, a definition of an event related to mobility may be necessary. Based on the event-triggered report currently under discussion in Rel-19 MIMO, and considering that the decision itself (e.g., the final decision) is performed by the gNB, and considering that all LTM CSI reports are L1 signaling, defining an event for mobility at the beam level (hereinafter, Case 1) may be appropriate. Furthermore, considering that event-triggered reports are ultimately used for making a handover decision, defining an event for mobility at the cell level (hereinafter, Case 2) may be appropriate. Meanwhile, in relation to this, the event instance described later may mean a case where a value calculated by a UE according to the condition of an event set by the gNB exceeds a threshold set by the gNB or derived by a prior promise or agreement.

[0181] 1. Case 1 - Defining Beam Level Events for Mobility

[0182] In Case 1, a UE can be defined as an event instance when the measurement results of measurement resources indicated by the gNB exceed a set threshold without any separate operation. This may be appropriate in a context where LTM CSI reporting operates on a beam basis (e.g., without operation of measurements on resources belonging to a candidate cell ID). In this case, the following examples may be considered for defining an event.

[0183] The UE can determine an event instance when the measurement value of at least one measurement resource among all measurement resources belonging to the channel measurement resource (CMR) of all reporting configurations for LTM CSI reporting reported at the direction of the gNB exceeds a threshold. This may be appropriate in terms of performing active monitoring since it is the definition of an event for mobility. In addition, since the mobility event is based on the configuration reported by the direction of the existing gNB, and the reporting is performed based on the preset reporting configuration after the event trigger is determined later, it may be advantageous in terms of reducing signaling overhead. In addition, since it is based on the reporting configuration that the gNB has preset to monitor, it may be advantageous in that the reporting desired by the gNB can be performed.

[0184] Alternatively, the UE may use only the resources with activated TCI state IDs among all measurement resources belonging to the CMR(s) of all reporting configurations configured for LTM CSI reporting as instructed by the gNB for defining an event. The UE may determine that an event instance is a case where the measurement value of at least one of such resources (e.g., resources with activated TCI state IDs) exceeds a threshold.

[0185] Alternatively, the UE may determine that an event instance is one in which a measurement value of at least one resource among all measurement resources belonging to a CMR of specific reporting configuration(s) among reporting configurations configured for LTM CSI reporting according to the instruction of the gNB exceeds a threshold. At this time, the specific reporting configuration may be indicated through a reporting ID (or reporting configuration ID) together with the configuration of the event by signaling such as RRC / MAC-CE / DCI of the gNB. Alternatively, the UE may derive a set of specific reporting IDs (or reporting configuration IDs) according to a prior agreement or contract. For example, the specific reporting ID may be derived as lowest - X reporting IDs and / or highest - X reporting IDs (among reporting configurations configured for LTM CSI reporting). For example, the UE may derive X lowest-value IDs or X highest-value IDs among reporting configuration IDs configured for the UE as the specific reporting ID set or the specific reporting ID. This can be useful in that, since it can be burdensome in terms of UE complexity for the UE to monitor all measurement resources, the UE can reduce the UE complexity to an appropriate level by monitoring a set of configured resources among all measurement resources. In addition, when reporting is performed after determining an event trigger at a later time, it can be advantageous in terms of reducing signaling overhead because it is based on a preset reporting configuration, and it can be advantageous in that the gNB can perform the desired reporting because it is based on a preset reporting configuration that the gNB wants to monitor.

[0186] The UE may be configured with a separate CMR (e.g., a set of measurement resources) for mobility events by the gNB, and may determine that an event instance occurs when a measurement value of at least one resource among all measurement resources belonging to the separate CMR exceeds a threshold. For example, the UE may be configured with a reporting configuration set for reporting by the gNB's instruction and a reporting configuration / CMR for separate events by the gNB. This may be appropriate / advantageous in terms of monitoring the quality of beams (separately) provided to the UE by allowing the UE to monitor a combination of resources that the reporting configuration set for reporting by the gNB's instruction does not cover.

[0187] In the examples of events described above, the threshold or threshold value may be explicitly indicated / set or derived through at least one of the following methods.

[0188] - The gNB can explicitly set the threshold value via RRC / MAC-CE / DCI. For example, the gNB can indicate to the UE a value such as L1-RSRP or L1-SINR as the threshold value, and the UE can use the indicated value such as L1-RSRP or L1-SINR as the threshold value for deriving an event instance. This can be appropriate / advantageous in that the gNB can indicate the threshold value according to its intention when considering that the beam quality is not constant depending on the location of the UE.

[0189] - And / or, the threshold or threshold value may be set / determined by a value determined by a prior promise or agreement. Since what the gNB ultimately wants to determine through event instances is a handover decision, it is necessary to ensure the minimum quality of candidate cells for the UE to perform handover, and the threshold or threshold value may not need to be variable, so this method may be appropriate.

[0190] - and / or, the threshold or threshold value may be set / determined based on the measurement value of a beam of a specific index explicitly indicated or implicitly derived by the gNB (e.g., L1-RSRP, L1-SINR, etc.). The most important factor in the hand-over decision may be the quality comparison between the serving cell and the neighboring cells. To take this into account / imitate, the UE may determine that a specific beam being served is a beam of a specific index determined by explicit indication or by implicit rule, and use the measurement value of the beam of the specific index as the threshold value to be compared with the measurement value of the beam for inducing the event (or, it is suitable to have the UE compare the measurement value of a specific beam being served with the measurement value of the beam for inducing the event). Alternatively, another important factor in the hand-over decision may be the quality comparison between neighboring cells. To take this into account / imitate this, the UE may determine the beam of a specific candidate cell set as a specific beam determined by an explicit instruction or an implicit rule, and use the measurement value of the specific beam as the threshold value to be compared with the measurement value of the beam for inducing the event (or, it may be appropriate to have the UE compare the measurement value of the beam of a specific candidate cell determined by an implicit rule or by explicitly instructing the UE to the beam of a specific candidate cell set as the threshold value). Meanwhile, the measurement value of the specific beam determined by the implicit rule here may be a specific measurement value among the report values ​​most recently reported by the UE to the gNB in ​​the LTM CSI report.

[0191] 2. Case 2 - Defining Cell-Level Events for Mobility

[0192] Since mobility ultimately aims to determine handovers, a process may be required to determine which candidate cells are of good quality. This cell quality derivation is defined in Radio Resource Management (RRM) measurements, and cell-level events can be defined to mimic this behavior at L1 or L2. Before defining such cell-level events, the quality of the candidate cells must first be defined. For example, at least one of the following options may be considered in determining cell quality as defined in the event.

[0193] (1) Option 1-1

[0194] In option 1-1, the UE may determine the quality of each candidate cell for the purpose of determining event trigger reporting based on the measurement value (e.g., RSRP) of a measurement resource of a specific index among the measurement resources of the candidate cells as instructed by the gNB (or according to a prior promise or agreement).

[0195] For example, the UE can be explicitly instructed by the gNB via signaling such as RRC / MAC-CE / DCI to provide measurement resources for assessing the quality of each candidate cell (for example, at least one measurement resource for evaluating cell quality among multiple measurement resources set for each candidate cell can be explicitly instructed), and the UE can determine / determine the measurement value of the instructed measurement resource as the quality of the candidate cell.

[0196] Alternatively, the UE may determine / judge the cell quality of the candidate cell based on the L1-RSRP measured for the SSB with the lowest (or highest) index among the SSBs of the candidate cell configured for LTM CSI reporting (e.g., by a prior agreement or contract).

[0197] Alternatively, the UE may determine / judge the L1-RSRP (Layer 1 Reference Signal Received Power) of an SSB of a specific index defined by a predetermined rule among the SSBs of the candidate cell set for each LTM CSI report as the cell quality of the candidate cell. For example, the predetermined rule may be a predetermined rule based on NZP CSI-RS (Non-Zero-Power Channel State Information Reference Signal) or NZP CSI-RS resources, and an SSB index associated with the largest number of NZP CSI-RSs among the SSBs may be determined as the specific index for measuring the quality of the candidate cell according to the predetermined rule.

[0198] (2) Option 1-2

[0199] In option 1-2, the UE may judge / decide the cell quality of each candidate cell for determining event trigger reporting based on the computation of measurement values ​​(e.g., RSRP) for measurement resources of specific indices among the measurement resources of the candidate cells as instructed by the gNB (or, according to a prior promise or agreement).

[0200] For example, the UE can be explicitly instructed by the gNB to provide measurement resources for determining the cell quality of each candidate cell through signaling such as RRC / MAC-CE / DCI, and can determine / judge the linear average or median of all or part of the measurement values ​​of the indicated measurement resources for each candidate cell as the quality of the candidate cell. Here, when the linear average or median of some of the measurement values ​​of the measurement resources is determined / judged as the quality of the candidate cell, some of the measurement values ​​of the measurement resources may be the remaining measurement values ​​excluding the top-X resources (e.g., X measurement resources from the measurement resource having the highest measurement value) and / or the lowest-Y resources (e.g., Y measurement resources from the measurement resource having the lowest measurement value) among the measurement values. This is to improve the reliability of the measurement. The X and / or Y may be values ​​instructed by the gNB or determined by a prior promise or agreement.

[0201] Alternatively, the UE may determine / judge the linear average or median value of all or part of the measurement values ​​of all measurement resources of each candidate cell set by the gNB as the quality of the candidate cell. Here, when the linear average or median value of some of the measurement values ​​of the measurement resources is determined / judged as the quality of the candidate cell, some of the measurement values ​​of the measurement resources may be the remaining measurement values ​​excluding the top-X resources (e.g., X measurement resources from the measurement resource having the highest measurement value) and / or the lowest-Y resources (e.g., Y measurement resources from the measurement resource having the lowest measurement value) among the measurement values ​​of the measurement resources. This is to improve the reliability of the measurement. The X and / or Y may be values ​​instructed by the gNB or determined by a prior promise or agreement.

[0202] Alternatively, the UE may determine the cell quality of at least one candidate cell or the at least one cell by determining the linear average or median of all or part of the measurement values ​​of all measurement resources configured for each of at least one candidate cell among the candidate cells configured (for mobility, LTM) from the gNB. Here, when determining / determining the linear average or median of some of the measurement values ​​of the measurement resources as the quality of the candidate cell, some of the measurement values ​​of the measurement resources may be the remaining measurement values ​​excluding the top-X resources (e.g., X measurement resources starting from the measurement resource having the highest measurement value) and / or the lowest-Y resources (e.g., Y measurement resources starting from the measurement resource having the lowest measurement value) among the measurement values ​​of the measurement resources. This is to improve the reliability of the measurement. The X and / or Y may be values ​​instructed by the gNB or determined by a prior agreement or promise.

[0203] (3) Determination of threshold values ​​in Option 1-1 and / or Option 1-2

[0204] The UE may determine / determine an event instance when the quality of a specific candidate cell exceeds a threshold based on the cell quality described above. Here, the threshold may be determined by at least one of the following methods.

[0205] - The gNB can explicitly set the threshold value via RRC / MAC-CE / DCI. For example, the gNB can indicate to the UE a value such as L1-RSRP or L1-SINR as the threshold value, and the UE can use the indicated value such as L1-RSRP or L1-SINR as the threshold value for deriving an event instance. This may be appropriate / advantageous in that the gNB can indicate the threshold value according to its intention when considering that the quality of the cell / candidate cell is not constant depending on the location of the UE.

[0206] - And / or, the threshold or threshold value may be set / determined based on a predetermined value determined by prior agreement or agreement. Ultimately, since the gNB seeks to determine the handover decision through event instances, the minimum quality of the cell where the UE will perform the handover must be guaranteed. Therefore, this method may be appropriate in that the threshold or threshold value may not need to be variable.

[0207] - and / or, the threshold or threshold value may be set / determined based on the quality of a specific candidate cell explicitly indicated or implicitly derived by the gNB. The most important factor in handover decision may be the quality comparison between the serving cell and the neighboring cell. To consider / imitate this, it may be appropriate for the UE to compare the quality of the serving cell (or a specific candidate cell) determined by explicit indication or by implicit rule (e.g., as the threshold value) with the quality value of the (other) candidate cell for inducing the event. Alternatively, another important factor in handover decision may be the quality comparison between neighboring cells. To consider / imitate this, it may be appropriate to have the UE compare the quality value of a specific candidate cell having an explicitly indicated cell ID or a specific candidate cell determined by an implicit rule (e.g., as the threshold value) with the quality value of the candidate cell for inducing the event. Meanwhile, the specific candidate cell determined by the implicit rule here may be determined based on the candidate cell IDs most recently reported by the UE to the gNB via LTM CSI reporting. For example, the specific candidate cell may be the candidate cell with the lowest cell ID or the highest cell ID among the candidate cells most recently reported via LTM CSI.

[0208] (4) The definition and settings of the above-described events can be summarized as follows.

[0209] 1) Definition of an event

[0210] Existing events can be defined based on cell quality, except for UE-initiated beam reports. However, from a RAN1 perspective, the definition of cell quality may be insufficient. UE-initiated beam reports are limited to indicating the beam to be selected for the UE, so the only event currently agreed upon is based on beam quality. While UE-initiated beam reports are a good starting point from a signaling design perspective, the event definitions should be distinct. Since they are intended for mobility, the reports should ultimately assist the gNB in ​​determining handover. Therefore, cell quality-based design considerations should be considered when defining events.

[0211] There are two possible implementation approaches based on the existing MIMO event definition. First, the cell quality judgment approach of the existing RRM measurement can be mimicked. For example, the quality of the candidate cell (e.g., the candidate cell for which the candidate cell ID is set) can be defined as the average value of the beams within the resource set having the same candidate cell ID. There are also various other approaches to mimic reasonable cell quality, such as using the average value of the remaining measurements after excluding the top-X (e.g., X measurements from the top-X measurements from among the measurements measured within the resource set) or the bottom-X resources (e.g., X measurements from the bottom-X measurements from among the measurements measured within the resource set). This approach serves the purpose, but the problem is the UE complexity, which requires the UE to always monitor the entire resource set for events.

[0212] Another approach is to define measurements for specific measurement resources as representative of cell quality. For example, SSB-based measurements for a specific index can be defined as cell quality at Layer 1 (L1). While this approach is not optimal for assessing cell quality compared to the first approach, it may be more appropriate given that LTM CSI reporting is L1 signaling. Both approaches have their own merits and drawbacks, and should be defined through detailed discussion. Regardless of the approach chosen, it may be important to include cell quality in the event definition.

[0213] > Proposed method: Introducing the cell quality of candidate cells for event definition, the following options can be discussed.

[0214] - Define cell quality by calculating the measurement value for a resource with a specific candidate cell ID (e.g., define the quality of the specific candidate cell as the average, linear average, etc. of the measurement values ​​of all measurement resources set for the specific candidate cell)

[0215] - Consider the measurement value for a specific resource with a specific candidate cell ID as the cell quality (e.g., among the measurement resources set for a specific candidate cell, the measurement value from a specific measurement resource designated / set to measure the cell quality is defined / considered as the cell quality).

[0216] The next step is to discuss which events to identify. As previously discussed, Events A3 and A5 are candidates proposed as reference events, and their definitions are as follows:

[0217] - Event A3: Neighbor becomes amount of offset better than PCell / PSCel)

[0218] - Event A5: PCell / PSCell becomes worse than absolute threshold1 AND Neighbor / SCell becomes better than another absolute threshold2

[0219] Events like these are directly related to handover decisions and are suitable as starting points for mobility events, but their implementation can be challenging. A key cause may be the lack of cell quality. As mentioned above, methods to mimic cell quality have been proposed, but they may lack the reliability of cell quality derived from existing L3 filtered measurements. This is because the filtering of LTM CSI reporting is not defined, and even if it is mimicked within the L1 measurement architecture, it can be difficult to determine the accuracy of multiple resources. Furthermore, even if events A3 and A5 are introduced to address these issues, they can lead to information duplication. This can be undesirable, as events for existing RRM measurements coexist with degraded versions of these events.

[0220] Given this context, L1-specific event definitions may be necessary, as the gNB determines whether a UE should be handed over based on existing RRM measurements, LTM CSI reports, etc. The advantage of L1 reporting is its agility and speed compared to RRM reporting. Therefore, it may be appropriate to start with the simplest event, A4 (neighbor cell surpasses absolute threshold), and expand as needed.

[0221] > Proposal: At a minimum, the following events could be introduced for mobility (or LTM):

[0222] - A4 Similar Event: Quality of at least one candidate cell becomes better than threshold

[0223] * FFS: A3-like, A5-like event

[0224] -- A3 Similar Event: Quality of at least one candidate cell becomes a threshold value better than the current beam

[0225] -- A5 Similar event: Quality of the current beam becomes worse than threshold1 AND Quality of at least one candidate cell becomes better than threshold2

[0226] 2) How to set up an event

[0227] The event configuration method should be based on the current reporting configuration method. This is because it is one of the simplest configuration methods, allowing event-related parameters to be selectively configured for specific reporting configurations. Event-related parameters may include event definitions (including thresholds), time window lengths, and the number of event instances for triggering. Considering the event triggering mechanism, since the UE must monitor and determine event instances within the configured time window, it may be appropriate to configure these parameters via RRC signaling.

[0228] > Proposal: Event triggered reporting can be configured via RRC signaling based on existing reporting settings.

[0229] - Events, thresholds, time window length, and number of instances can be optionally set for reporting settings.

[0230] 2. Event trigger judgment

[0231] FIG. 9 is a diagram illustrating a method for a UE to determine an event trigger in relation to mobility.

[0232] The UE may receive all or part of the following parameters from the gNB through signaling such as RRC / MAC-CE / DCI or may derive them from predefined rules to perform event trigger determination;

[0233] - Threshold, time window, number of event instances (N).

[0234] Here, for defining the time window, all or part of the following parameters can be set by the gNB through signaling such as RRC / MAC-CE / DCI or can be derived from predefined rules. For example, the time window can be defined based on parameters such as periodicity, reference SCS, offset in slot and / or symbol, duration in slot(s) and / or symbol(s).

[0235] The UE may determine an event trigger as follows based on the parameters indicated or derived as described above. For example, the UE may determine that an event is triggered if an event instance occurs N or more times within a time window.

[0236] At this time, if the definition of the event is defined according to the candidate cell / cells, the threshold, time window, and N values ​​may be set to different values ​​for each candidate cell. This method can individually set the threshold, time window, and N values ​​so that the hurdle / criteria for the event trigger are lowered for specific cells where cell switching via LTM needs to be performed more easily (e.g., cells that are already heavily loaded and / or NES (Network Energy Saving) cells), which can help secure scheduling flexibility of the network as a result.

[0237] The following may be considered when determining an event trigger:

[0238] (1) Event trigger judgment

[0239] Event trigger determination may mean that the UE determines whether to trigger a report (e.g., a report related to LTM) based on an event that has occurred. This can be accomplished in various ways, but for design consistency, it may be appropriate to follow a MIMO scheme. For example, as illustrated in FIG. 9, if a previously defined event condition is satisfied, it can be defined as an event instance, and if a configurable number (M) of event instances (or a configured number (M) of event instances) occur within a configurable time window (or a configured time window), the UE may determine that the event has been triggered.

[0240] Here, the time window can be a set of consecutive slots or symbols, and its length can also be set. However, the time windows are considered to be placed consecutively without overlap regardless of whether an event is triggered or an event instance occurs, thereby eliminating unnecessary ambiguity.

[0241] > Proposal: An event can be triggered when the number of event instances within a time window is greater than or equal to a set value, where the time window can also be a configurable parameter.

[0242] 3. UE actions based on event trigger reports

[0243] By the event for LTM defined by the method described in Sections '1' and '2' and the trigger determination of the event, the UE can determine that the event is triggered in mobility. In this case, the UE can report the event trigger report to the gNB through signaling such as UCI or MAC-CE. For example, if the UE determines that the event is triggered, the UE can report that the event is triggered to the gNB by reporting event ID(s), report ID(s), and / or candidate cell ID(s). Thereafter, subsequent reporting (or subsequent reporting, measurement reporting) can be performed according to the scheme below. The subsequent subsequent reporting at this time can mean reporting on measurement information (e.g., index of measurement resources and / or measured L1-RSRP or L1-SINR) for event instances in the event trigger determination.

[0244] (1) Scheme 1

[0245] In Scheme 1, the UE reports to the gNB that an event is triggered (e.g., an event trigger report) and can perform subsequent reports (e.g., subsequent reports) according to the scheduling of the gNB.

[0246] When a UE reports to the gNB that it is an event trigger, the UE may report the event trigger (e.g., event triggered) through signaling of UCI (uplink control information) on a PUCCH resource configured by the gNB for the purpose of performing an event trigger report, or MAC-CE on a PUSCH resource previously configured by the gNB for the purpose of performing an event trigger report. Such a report may be performed using a 1-bit indication, etc., when there is only a single event for LTM configured for the UE. When there are multiple events configured for the UE (or, even when there is only a single event, when detailed information needs to be conveyed in addition to whether the event occurred), the event trigger report may include at least one of the following pieces of information.

[0247] - {Event ID(s), Reporting Setting ID(s) used to define the triggered event, Candidate Cell ID(s) that caused the event trigger}

[0248] When the UE performs the event-triggered reporting via PUCCH (and / or reports one of multiple events, report IDs, or candidate cell IDs among the above information), the information can be implicitly reported to the gNB by reporting via different UL resources configured for each piece of information. For example, in relation to a case where an event is triggered for different candidate cells (e.g., a case where events are triggered for multiple candidate cells), the UE can be configured with different PUCCH resources for each configured candidate cell (or candidate cell for the configured reporting purpose) from the gNB. In this case, the UE can perform the event-triggered reporting on the PUCCH resource corresponding to each candidate cell for which an event is triggered among the PUCCH resources. For example, when performing event-triggered reporting for each of candidate cell 1 and candidate cell 2, the UE can perform the event-triggered reporting for candidate cell 1 on PUCCH resource 1 configured for candidate cell 1, and perform the event-triggered reporting for candidate cell 2 on PUCCH resource 2 configured for candidate cell 2. In this case, even if the UE does not report information about the candidate cell ID to the gNB through an event trigger report, the gNB can recognize / identify which candidate cell the event trigger report is for through the PUCCH resource on which the event trigger report is performed.

[0249] Setting aside separate resources for subsequent reporting may impose additional burden on the gNB, requiring it to monitor and / or perform blind decoding (BD). Therefore, when a UE reports an event trigger to the gNB, the gNB can instruct the UE to report LTM CSI via signaling, such as MAC-CE / DCI, to reduce unnecessary monitoring and / or blind decoding.

[0250] (2) Scheme 2

[0251] In Scheme 2, the UE reports to the gNB that it is an event trigger, and can perform subsequent follow-up reporting based on resources pre-configured for event trigger reporting.

[0252] The operation of the UE reporting to the gNB that an event is triggered (e.g., the event trigger reporting operation) is the same as in scheme 1, but the difference is that subsequent subsequent reports are performed on pre-configured resources rather than being separately instructed according to the scheduling of the gNB. In this case, the UE performs the operation of reporting the event trigger to the gNB through signaling such as SR (scheduling request) on the configured PUCCH resource (via UCI), and can perform subsequent subsequent reports through signaling of UCI or MAC-CE.

[0253] Unlike Scheme 1, since subsequent reports are performed on pre-configured resources without separate scheduling after a report indicating that an event is triggered (e.g., an event-triggered report), collisions between subsequent reports may occur. To prevent such collisions, information indicating which subsequent reports will be performed based on priority rules defined in advance according to prior agreement among subsequent reports following an event-triggered report may be included. For example, the UE may report the event-triggered report by including all or part of the event ID(s), the report configuration ID(s) used in the definition of the triggered event, the candidate cell ID(s) that caused the event trigger, and the priority index, and perform the subsequent report. For example, the UE may include some information of the subsequent report in relation to the above priority rules in the event-triggered report.

[0254] The UE may receive periodic PUCCH or PUSCH resources for subsequent reporting via UCI from the gNB along with the event configuration. Subsequently, the UE may perform subsequent reporting based on the most recent measurement value among the measurement resources that determined the event trigger or the event instances per candidate cell, or based on L1 filtering of the measurement resources that determined the event trigger or the event instances per candidate cell.

[0255] (3) Scheme 3

[0256] In Scheme 3, the UE can report both the event triggered report and subsequent follow-up reports on resources pre-configured for event triggered reporting.

[0257] At this time, when the UE reports an event trigger report to the gNB, the UE may perform the event trigger report and the subsequent report via UCI on PUCCH resources configured by the gNB for the event trigger report and the subsequent report, or may perform the event trigger report and the subsequent report via signaling of MAC-CE on PUSCH resources configured in advance by the gNB for the event trigger report and the subsequent report.

[0258] An event trigger report and / or subsequent follow-up reports may include all or part of the event ID(s), the reporting configuration ID(s) used in the definition of the triggered event, the candidate cell ID(s) that caused the event trigger, the measurement resource or candidate cell indices, and the measurement values ​​corresponding to the measurement resource or candidate cell indices.

[0259] A summary of the above-described event report may be as follows.

[0260] Event Report

[0261] When a UE determines that an event has been triggered, it can perform the following reporting (e.g., report the event occurrence to the gNB via a PUCCH transmission). If the event type is single, this can be done with a 1-bit indication. If there are multiple event types, this can be done using a report ID configured for the event. However, it may be necessary to determine whether the UE should directly report the measurement result that triggered the event. In this regard, MIMO has agreed to support both of the following options.

[0262] - Option 1. Mode A (Dynamic UCI Scheduling by the gNB): In Mode A, the UE notifies the gNB of the occurrence of an event, and measurement reporting (e.g., subsequent reporting) for that event is performed according to the gNB's scheduling. For example, the gNB can trigger a related measurement report (e.g., subsequent reporting) via DCI after recognizing that an event has occurred. This is a simple and efficient method, but has the disadvantage of relatively high delay compared to Mode B, which will be described later.

[0263] - Option 2. Mode B (UCI in pre-configured resources for the second UL channel): The reporting scheme of Mode B may be such that the UE performs measurement reporting (e.g., subsequent reporting) using pre-configured periodic uplink resources without separate scheduling or resource configuration after an event-triggered report. After transmitting an event-triggered report, the UE may use some of these resources to perform measurement reporting (e.g., subsequent reporting). However, this scheme may increase the complexity of the gNB, as the gNB may need to monitor some or all of the configured periodic uplink resources in certain situations. In this respect, it has been agreed to adopt Mode A as the default for MIMO.

[0264] Given that LTM CSI reporting has a high priority, it's natural that event-triggered reporting for Rel-19 mobility enhancements should also have a high priority. Given this, if event-triggered reporting for mobility is considered in Mode B, the UE may drop most uplink transmissions that conflict with its periodic uplink resources. This severely limits the scheduling flexibility of the gNB. This is undesirable, and given that LTM CSI reporting is signaled via UCI and has a low latency due to its high priority, Mode A may be sufficient.

[0265] > Proposal: When an event is triggered, the UE may transmit PUCCH (1 bit or bits) to request a second uplink channel resource for transmitting LTM CSI reports (e.g., measurement reports, follow-up reports).

[0266] - FFS: Request format (e.g. SR or new UCI type)

[0267] 4. Priority rules for event trigger reporting

[0268] An event trigger report to which the priority rules described below apply may refer to a subsequent subsequent report (e.g., a measurement report) other than the report that notifies the gNB that it is an event trigger as described in Section 3.

[0269] If both an event-triggered report for LTM and a gNB-initiated report are configured for the UE, and both reports are UCI-based, a collision may occur between the two reports. In this case, the UE may prioritize the event-triggered report (e.g., the event-triggered report for LTM). This may be desirable since the event-triggered report is configured for the purpose of understanding the UE's current environment. Alternatively, if both an event-triggered report for LTM and a gNB-initiated report are configured for the UE, and both reports are UCI-based, a collision may occur between the two reports. In this case, the UE may prioritize the gNB-initiated report. This may be desirable since the gNB is the entity making the handover decision.

[0270] When multiple events are configured on a UE, conflicts can arise between reports triggered by different events. Therefore, the following can be considered as priorities for different event-triggered reports. For example, the following options can be considered for determining which conflicting event-triggered reports are prioritized and which are dropped.

[0271] - In case of a conflict between two different event trigger reports, the priority may be determined based on the report ID, the event trigger time, the lowest (or highest) cell ID included in the report, the number of cell IDs included in the report, and / or a high (or low) threshold between the two event trigger reports. For example, an event trigger report with a high threshold (e.g., a threshold as an event trigger condition) has a higher priority than an event trigger report with a low threshold (e.g., a threshold as an event trigger condition).

[0272] - As described above, when the priority of a specific report is determined by the contents of the report, such as the lowest (or highest) cell ID included in the event trigger report or the number of cell IDs included in the event trigger report, the base station may not know the priority among the event trigger reports until the event trigger report is decoded. This may be a problem due to ambiguity when the event trigger report is signaled with UCI. When signaled with MAC-CE, the contents described above are distinguished in the MAC header, so the base station can quickly recognize the priority according to the contents described above by only decoding the MAC header of the event trigger report.

[0273] - If the UE only reports whether an event has occurred to the gNB, and performs the event-triggered report (or subsequent report, measurement report) according to the gNB's scheduling, the problem described above (e.g., collision between event-triggered reports) may not occur. Even if the UE performs an event-triggered report (e.g., subsequent report) after the event occurrence report (for periodic uplink resources), the gNB can still know which event-triggered report the UE will transmit through the first report. In this case, the reception timing for both the report scheduled by the gNB and the event-triggered report (or subsequent report) to be reported soon can be known. Even in this case, if the priorities according to the report contents are different, the gNB may not know which report is being performed before decoding, and may have to BD both reports.

[0274] For example, event trigger report 1 and event trigger report 2 may conflict. In this case, if the priority is determined based on the content included in event trigger report 1 and the content included in event trigger report 2, the base station may not be able to determine the priority. If the report of whether an event has occurred includes information about the event (or, report ID, cell ID, etc.), the gNB can determine which report will be reported with priority according to the predefined priority rules of the LTM CSI report. Therefore, there may be no ambiguity regarding the UE operation at the gNB level. On the other hand, the event occurrence report may simply report that an event has occurred with a 1-bit indication, etc., and the value that determines the priority in event trigger report 1 and event trigger report 2 may be determined by the report content. In this case, the gNB still cannot determine which subsequent report the UE will receive with priority. To solve this case, the UE may transmit information related to priority determination in addition to ON / OFF information in the event occurrence report.

[0275] FIG. 10 is a diagram illustrating a method for a first device to perform event trigger-based measurement reporting related to mobility.

[0276] As described above, the first device may be a UE that performs a mobility-related procedure such as LTM (L1 / L2 Triggered Mobility). The first device may perform an event-triggered measurement report related to mobility. For example, the first device may determine an event instance based on mobility-related event-triggered measurement report configuration / measurement configuration information, and if the number of event instances is greater than or equal to a specific threshold, may trigger a measurement report related to the mobility or LTM, and report the trigger information / measurement information therefor to the second device. Hereinafter, a method for the first device to perform an event-triggered measurement report related to mobility based on the proposed method described in at least one of the above-described sections 1 to 4 will be described in detail.

[0277] Specifically, referring to FIG. 10, a first device may receive measurement configuration information for an event-triggered measurement report related to mobility from a second device (S101). The measurement configuration information may include information for setting at least one candidate cell related to the LTM or mobility, measurement resources for each of the at least one candidate cell, a threshold value related to the event trigger, and a threshold number. Here, the second device may be a base station, a gNB, or a network.

[0278] Next, the first device can measure the cell quality for each of at least one candidate cell based on the measurement configuration information (S103). As described in Case 2 of Section 2, cell-level events can be defined for mobility-related measurement reports for the first device. At this time, the first device can measure the cell quality for each of the at least one candidate cell based on an SSB of a specific index among a plurality of SSBs (Synchronization signal blocks) configured for each of the at least one candidate cell. Here, the specific index can be determined based on the number of associated CSI-RS (Channel State Information-Reference Signal) resources for each of the plurality of SSBs. For example, the specific index can be determined as an index of an SSB having the largest number of associated CSI-RS (Channel State Information-Reference Signal) resources among the plurality of SSBs. For example, the first device may determine a specific SSB1 among the first SSBs for the first candidate cell, which has a large number of associated CSI-RS resources, as the SSB of the specific index, and may determine a value such as L1-RSRP measured at the SSB of the specific index as the quality of the first candidate cell. Furthermore, the first device may determine a specific SSB2 among the second SSBs for the second candidate cell, which has a large number of associated CSI-RS resources, as the SSB of the specific index, and may determine a value such as L1-RSRP measured at the SSB of the specific index as the quality of the second candidate cell.

[0279] Alternatively, the specific index may be determined as the highest index among the indices of the plurality of SSBs. For example, the first device may determine the specific SSB having the highest index among the indices of the first SSBs for the first candidate cell as the SSB of the specific index, and determine a value such as L1-RSRP measured at the SSB of the specific index as the quality of the first candidate cell. Alternatively, the specific index may be determined as the lowest index among the indices of the plurality of SSBs. For example, the first device may determine the specific SSB having the lowest index among the indices of the first SSBs for the first candidate cell as the SSB of the specific index, and determine a value such as L1-RSRP measured at the SSB of the specific index as the quality of the first candidate cell.

[0280] Alternatively, the specific index may be indicated by the second device for each of the at least one candidate cell. For example, when a first candidate cell and a second candidate cell are configured in relation to mobility or LTM, the first device may directly be indicated a specific measurement resource / SSB ID among at least one measurement resource / SSB for the first candidate cell from the second device via MAC-CE / RRC / DCI, and may directly be indicated a specific measurement resource / SSB ID among at least one measurement resource / SSB for the second candidate cell from the second device.

[0281] Next, the first device can determine / judge an event instance related to the event trigger based on the cell quality of each of the at least one candidate cell (S105). For example, the first device can determine an event instance of a specific candidate cell among the at least one candidate cell based on the quality of the specific candidate cell being equal to or higher than the specific threshold quality. In this case, if the number of event instances of the specific candidate cell is equal to or higher than the specific threshold number, the first device can trigger the event-triggered based measurement report for the specific candidate cell, and transmit an event trigger report on the occurrence of the event trigger to the second device.

[0282] For example, the first device may report an event trigger report regarding the occurrence of an event trigger via a 1-bit indicator. Alternatively, the event trigger report may include information about at least one of the event ID(s), the report configuration ID(s) used to define the triggered event, and the candidate cell ID(s) that caused the event trigger. For example, as described in “3. UE Operations According to Event Trigger Reporting,” the first device may transmit the event trigger report to the second device on a resource scheduled by the second device (such as a PUCCH UCI) or a pre-configured resource. Further, the subsequent report may also be transmitted on a resource scheduled by the second device (such as a PUCCH UCI) or a pre-configured resource. In the former case, the first device may request the second device to schedule a resource for transmitting the subsequent report via a transmission such as an SR.

[0283] FIG. 11 is a diagram illustrating a method for a second device to receive a mobility-related event trigger-based measurement report from a first device.

[0284] Referring to FIG. 11, a second device may transmit measurement configuration information for the event-triggered measurement report related to mobility to a first device (S111). The measurement configuration information may include information for setting at least one candidate cell related to the LTM or mobility, measurement resources for each of the at least one candidate cell, and a threshold value and threshold number related to the event trigger. Here, the second device may be a base station, gNB, or a network, and the first device may be a UE.

[0285] Next, the second device can receive the measurement report event-triggered by the first device based on the cell quality for each of the at least one candidate cell (S113). As described in Section 2 Case 2, the second device can define / set a cell-level event for the mobility-related measurement report to the first device. At this time, the cell quality for each of the at least one candidate cell may be a value measured based on an SSB of a specific index among a plurality of SSBs (Synchronization signal blocks) set for each of the at least one candidate cell. Here, the specific index may be determined based on the number of associated CSI-RS (Channel State Information-Reference Signal) resources for each of the plurality of SSBs. For example, the specific index may be determined as an index of an SSB having a largest number of associated CSI-RS (Channel State Information-Reference Signal) resources among the plurality of SSBs.

[0286] Alternatively, the specific index may be determined as the highest index among the indices of the plurality of SSBs. For example, the cell quality for the first candidate cell may be an L1-RSRP value measured for a specific SSB having the highest index among the indices of the first SSBs for the first candidate cell. Alternatively, the specific index may be determined as the lowest index among the indices of the plurality of SSBs. For example, the cell quality for the first candidate cell may be a value such as an L1-RSRP measured for a specific SSB having the lowest index among the indices of the first SSBs for the first candidate cell. Alternatively, the second device may directly indicate to the first device a measurement resource / SSB ID associated with the measurement of cell quality among the measurement resources / SSBs for each of the plurality of candidate cells associated with the mobility or LTM via MAC-CE / DCI / RRC.

[0287] As described above, the first device can determine / judge an event instance related to the event trigger based on the cell quality of each of the at least one candidate cell, and when the number of the event instances is greater than or equal to a specific threshold number, the second device can receive an event-triggered measurement report for at least one candidate cell or a specific candidate cell from the first device. The second device can receive a subsequent report including an event-triggered report on the occurrence of an event trigger and a measurement value of a cell quality as a measurement report reported from the first device. For example, the second device can recognize through the event-triggered report that a measurement report related to mobility is event-triggered by the first device, and can receive measurement values ​​for the at least one candidate cell that is event-triggered through the subsequent report.

[0288] For example, the second device may receive an event trigger report regarding the occurrence of an event trigger via a 1-bit indicator. Alternatively, the event trigger report may include at least one of event ID(s), report configuration ID(s) used to define the triggered event, and candidate cell ID(s) that caused the event trigger. For example, as described in “3. UE Operation According to Event Trigger Report”, the second device may receive the event trigger report on a resource scheduled by the second device (such as a PUCCH UCI) or a pre-configured resource. Next, the second device may receive a follow-up report including measurement values / measurement information related to the event trigger report after receiving the event trigger report. Here, the follow-up information may be received on a resource scheduled by the second device (such as a PUCCH UCI) or a pre-configured resource. In the former case, the second device may be requested to schedule a resource for transmitting the follow-up report from the first device via an SR, etc.

[0289] In this way, the proposed invention can effectively ensure that measurement reports that are consistent with the purpose of handover decisions are event-triggered by the first device by defining events at the candidate cell level in mobility-related event-triggered reporting. Alternatively, the proposed invention can effectively secure the effectiveness of defining events at the cell level in mobility-related event-triggered reporting by clearly defining judgment criteria for measuring the quality of candidate cells. Alternatively, the proposed invention can minimize UE complexity / load in cell quality measurement / monitoring by limiting specific resources for determining cell quality to one or some of the multiple resources set for the candidate cell.

[0290] Examples of communication systems to which the invention applies

[0291] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts of the present invention disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0292] Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings / descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

[0293] Figure 12 illustrates a communication system applied to the present invention.

[0294] Referring to FIG. 12, a communication system (1) applied to the present invention includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0295] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0296] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present invention.

[0297] Examples of wireless devices to which the present invention is applied

[0298] Figure 13 illustrates a wireless device applicable to the present invention.

[0299] Referring to FIG. 13, 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). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 12.

[0300] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, 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). In addition, 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 code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chipset 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. In the present invention, a wireless device may also mean a communication modem / circuit / chipset.

[0301] According to one example, the first wireless device or first device (100) may include a processor (102) and a memory (104) connected to the RF transceiver. The memory (104) may include at least one program capable of performing operations related to the embodiments described in FIGS. 8 to 11. The operations include: the first device receiving measurement configuration information for the event-triggered measurement report related to mobility from the second device; the first device measuring cell quality for each of at least one candidate cell based on the measurement configuration information; and the first device determining an event instance related to the event-trigger based on the cell quality of each of the at least one candidate cell, wherein the cell quality of each of the at least one candidate cell may be measured based on a synchronization signal block (SSB) of a specific index among a plurality of SSBs configured for each of the at least one candidate cell.

[0302] Specifically, the first wireless device or the first device controls the processor (102) of (100) the transceiver (106) so that the first device (100) controls the RF transceiver to receive measurement configuration information for the event-triggered measurement report related to mobility from the second device, measure cell quality for each of at least one candidate cell based on the measurement configuration information, and determine an event instance related to the event-trigger based on the cell quality of each of the at least one candidate cell, and the cell quality of each of the at least one candidate cell can be measured based on an SSB of a specific index among a plurality of SSBs (Synchronization signal blocks) set for each of the at least one candidate cell.

[0303] Alternatively, a processing device controlling a first device may include at least one processor; and at least one memory coupled to the at least one processor and storing instructions. The instructions, when executed by the at least one processor, cause the first device to: receive measurement configuration information for the event-triggered measurement report related to mobility from the second device; measure cell quality for each of at least one candidate cell based on the measurement configuration information; and cause the first device to determine an event instance related to the event-trigger based on the cell quality of each of the at least one candidate cell, wherein the cell quality of each of the at least one candidate cell may be measured based on a synchronization signal block (SSB) of a specific index among a plurality of SSBs configured for each of the at least one candidate cell.

[0304] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further 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, proposals, methods, and / or operational flowcharts disclosed in this document. For example, 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). Furthermore, 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 code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, 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. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0305] According to one example, the second wireless device or second apparatus (200) may include a processor (202) and a memory (204) connected to the RF transceiver. The memory (204) may include at least one program capable of performing operations related to the embodiments described in FIGS. 8 to 11.

[0306] Specifically, the processor (202) of the second wireless device or base station (200) controls the transceiver (206) or the RF transceiver to transmit measurement configuration information for the event-triggered measurement report related to mobility to the first device, and receives the measurement report event-triggered by the first device based on cell quality for each of at least one candidate cell, wherein the cell quality of each of the at least one candidate cell can be measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

[0307] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, 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 operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. 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, proposals and / or methods disclosed herein, 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, proposals, methods and / or operational flowcharts disclosed herein.

[0308] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document 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 operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0309] 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 configured as 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.

[0310] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, 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, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can 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 user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0311] Examples of wireless devices to which the present invention is applied

[0312] Figure 14 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case / service.

[0313] Referring to FIG. 14, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 13 and may be composed of various elements, components, units / units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and an additional element (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 14. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 13. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0314] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 12, 100a), a vehicle (Fig. 12, 100b-1, 100b-2), an XR device (Fig. 12, 100c), a portable device (Fig. 12, 100d), a home appliance (Fig. 12, 100e), an IoT device (Fig. 12, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 12, 400), a base station (Fig. 12, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0315] In FIG. 14, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of a set of one or more processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0316] Here, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. At this time, for example, 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. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification may perform communication based on LTE-M technology. At this time, for example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, 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. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification 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. For example, 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.

[0317] The embodiments described above are combinations of components and features of the present invention in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form an embodiment of the present invention by combining some components and / or features. The order of operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form an embodiment or may be incorporated as a new claim through a post-application amendment.

[0318] In this document, embodiments of the present invention have been described primarily focusing on the signal transmission and reception relationship between a terminal and a base station. This transmission and reception relationship is equally / similarly extended to signal transmission and reception between a terminal and a relay or a base station and a relay. Certain operations described as being performed by a base station in this document may, in some cases, be performed by its upper node. That is, it is obvious that various operations performed for communication with a terminal in a network composed of multiple network nodes including a base station may be performed by the base station or other network nodes other than the base station. The base station may be replaced by terms such as fixed station, Node B, eNode B (eNB), and access point. In addition, the terminal may be replaced by terms such as UE (User Equipment), MS (Mobile Station), MSS (Mobile Subscriber Station).

[0319] Embodiments of the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0320] When implemented via firmware or software, an embodiment of the present invention may be implemented in the form of modules, procedures, functions, etc. that perform the functions or operations described above. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located within or outside the processor and may exchange data with the processor via various known means.

[0321] It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the scope of the invention. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

[0322] The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims

1. In the method, A step in which a first device receives measurement setup information for a mobility-related event trigger-based measurement report from a second device; The first device measures the cell quality for each of at least one candidate cell based on the measurement setting information; and The first device comprises a step of determining an event instance associated with the event-trigger based on the cell quality of each of the at least one candidate cell, A method wherein the cell quality of each of the at least one candidate cell is measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

2. In paragraph 1, A method wherein the specific index is determined based on the number of associated CSI-RS (Channel State Information-Reference Signal) resources for each of the plurality of SSBs.

3. In paragraph 1, A method wherein the specific index is determined as the index of an SSB having the largest number of associated CSI-RS (Channel State Information-Reference Signal) resources among the plurality of SSBs.

4. In paragraph 1, A method wherein the specific index is determined as the highest index among the indices of the plurality of SSBs.

5. In paragraph 1, A method wherein the specific index is determined as the lowest index among the indices of the plurality of SSBs.

6. In paragraph 1, A method wherein said specific index is indicated for each of said at least one candidate cell by said second device.

7. In paragraph 1, The above measurement setting information includes information about a specific threshold quality and a specific threshold number, A method wherein the first device determines an event instance of a specific candidate cell based on the quality of the specific candidate cell among the at least one candidate cell being equal to or greater than the specific threshold quality.

8. In paragraph 7, A method wherein the first device triggers the event trigger-based measurement report based on the number of the event instances being greater than or equal to the specific threshold number.

9. In paragraph 1, A method wherein the above measurement setting information is related to LTM (L1 / L2 Triggered Mobility).

10. In at least one non-transitory computer-readable recording medium, Contains instructions that perform operations when executed by at least one processor, The above actions are, The first device receives measurement setup information for mobility-related event trigger-based measurement reporting from the second device; The first device measures cell quality for each of at least one candidate cell based on the measurement setting information; and wherein the first device comprises determining an event instance associated with the event-trigger based on a cell quality of each of the at least one candidate cell; At least one non-transitory computer-readable recording medium, wherein the cell quality of each of the at least one candidate cell is measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

11. In the first device, RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, The processor controls the RF transceiver to receive measurement configuration information for an event trigger-based measurement report related to mobility from a second device, measures cell quality for each of at least one candidate cell based on the measurement configuration information, and determines an event instance related to the event-trigger based on the cell quality of each of the at least one candidate cell. A first device, wherein the cell quality of each of the at least one candidate cell is measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

12. In paragraph 11, A first device, wherein the specific index is determined based on the number of associated CSI-RS (Channel State Information-Reference Signal) resources for each of the plurality of SSBs.

13. In a processing device that controls the first device, at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said first device causes: Receive measurement configuration information for an event trigger-based measurement report related to mobility from a second device, measure cell quality for each of at least one candidate cell based on the measurement configuration information, and determine an event instance related to the event-trigger based on the cell quality of each of the at least one candidate cell. A processing device, wherein the cell quality of each of the at least one candidate cell is measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

14. In the method, A step in which the second device transmits measurement setup information for an event trigger-based measurement report related to mobility to the first device; and The second device comprises a step of receiving the measurement report event-triggered by the first device based on cell quality for each of at least one candidate cell, A method wherein the cell quality of each of the at least one candidate cell is measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

15. In the second device, RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, The processor controls the RF transceiver to transmit measurement setup information for an event-triggered measurement report related to mobility to the first device, and receives the measurement report event-triggered by the first device based on cell quality for each of at least one candidate cell, A second device, wherein the cell quality of each of the at least one candidate cell is measured based on an SSB (Synchronization signal block) of a specific index among a plurality of SSBs set for each of the at least one candidate cell.

Images