Method and apparatus for setting performance monitoring period of artificial intelligence and / or machine learning model

Abstract

Provided are a method and an apparatus for setting a performance monitoring period of an artificial intelligence (AI) / machine learning (ML) model. A terminal receives, from a base station, first configuration information for monitoring the performance of an AI / ML model. Here, the first configuration information includes information regarding a first reference signal (RS) resource and at least one monitoring period associated with the first reference signal resource. In addition, the terminal performs monitoring of the performance of the AI / ML model on the basis of a first monitoring period from among the at least one monitoring period. Subsequently, the terminal receives, from the base station, signaling indicating a change to a second monitoring period from among the at least one monitoring period and performs monitoring of the performance of the AI / ML model on the basis of the second monitoring period.

Description

Method and device for setting a performance monitoring cycle for artificial intelligence and / or machine learning models

[0001] This specification relates to wireless communications applicable to 5G NR, 5G-Advanced and 6G.

[0002] As more and more communication devices demand ever-increasing communication traffic, the need for next-generation 5G systems, which offer enhanced wireless broadband communication capabilities over existing LTE systems, is growing. This next-generation 5G system, known as NewRAT, differentiates communication scenarios into Enhanced Mobile BroadBand (eMBB), Ultra-reliability and low-latency communication (URLLC), and Massive Machine-Type Communications (mMTC).

[0003] Here, eMBB is a next-generation mobile communication scenario with characteristics such as High Spectrum Efficiency, High User Experienced Data Rate, and High Peak Data Rate; URLLC is a next-generation mobile communication scenario with characteristics such as Ultra Reliable, Ultra Low Latency, and Ultra High Availability (e.g., V2X, Emergency Service, and Remote Control); and mMTC is a next-generation mobile communication scenario with characteristics such as Low Cost, Low Energy, Short Packet, and Massive Connectivity (e.g., IoT).

[0004] An object of the present specification is to provide a method and device for measuring the accuracy of AI / ML deployed in a terminal capable of performing beam management using AI / ML in a wireless communication system, wherein at least one model monitoring cycle is set and the model monitoring cycle is adaptively changed according to signaling from a base station.

[0005] One embodiment of the present specification provides a method for a wireless communication system in which a terminal receives first configuration information for performance monitoring of an artificial intelligence (AI) / machine learning (ML) model from a base station. Here, the first configuration information includes information on a first reference signal (RS) resource and at least one monitoring period associated with the first reference signal resource. Then, the terminal performs performance monitoring of the AI / ML model based on the first monitoring period among the at least one monitoring period. Thereafter, the terminal receives signaling from the base station indicating a change to a second monitoring period among the at least one monitoring period, and performs performance monitoring of the AI / ML model based on the second monitoring period.

[0006] In addition, one embodiment of the present specification provides a method in which, in a wireless communication system, a base station transmits first configuration information for performance monitoring of an AI / ML model to a terminal. Here, the first configuration information includes information on a first reference signal (RS) resource and at least one monitoring period associated with the first reference signal resource. Then, the base station transmits a first reference signal to the terminal based on the first monitoring period among the at least one monitoring period. Thereafter, the base station transmits a signaling indicating a change to a second monitoring period among the at least one monitoring period to the terminal, and transmits the first reference signal based on the second monitoring period.

[0007] In addition, one embodiment of the present invention provides a wireless communication system comprising at least one processor, and at least one memory storing instructions and being operably electrically connectable to the at least one processor, wherein the operation performed based on the instructions being executed by the at least one processor is: receiving first configuration information for performance monitoring of an AI / ML model from a base station. Here, the first configuration information includes information on a first reference signal (RS) resource and at least one monitoring period associated with the first reference signal resource. Then, performance monitoring of the AI / ML model is performed based on the first monitoring period among the at least one monitoring period. Thereafter, a terminal is provided that receives signaling from the base station instructing a change to a second monitoring period among the at least one monitoring period, and performs performance monitoring of the AI / ML model based on the second monitoring period.

[0008] In addition, one embodiment of the present invention provides a wireless communication system, comprising at least one processor, and at least one memory storing instructions and being operably electrically connectable to the at least one processor, wherein the operation performed based on the instructions being executed by the at least one processor is: transmitting first configuration information for performance monitoring of an AI / ML model to a terminal, wherein the first configuration information includes information on a first reference signal (RS) resource and at least one monitoring period associated with the first reference signal resource. Then, the base station transmits a first reference signal to the terminal based on the first monitoring period among the at least one monitoring period. Thereafter, the base station transmits signaling instructing a change to a second monitoring period among the at least one monitoring period to the terminal, and transmits the first reference signal based on the second monitoring period.

[0009] The base station may transmit second configuration information for inference of an AI / ML model to the terminal, and the terminal may receive the second configuration information. Here, the second configuration information may include information about a second reference signal resource and an inference cycle associated with the second reference signal resource.

[0010] The base station can transmit a second reference signal based on the inference cycle, and the terminal can perform inference of the AI / ML model based on the inference cycle.

[0011] The terminal transmits the inference results and performance monitoring results of the AI / ML model to the base station, and the base station can receive them.

[0012] The above first setting information and the above second setting information are transmitted and received via an RRC (radio resource control) message, and the signaling may be L1 (layer 1) signaling or L2 (layer 2) signaling.

[0013] Preferably, at least one monitoring period can be set to a multiple of the inference period.

[0014] Communication techniques utilizing AI / ML models require continuous model monitoring. However, excessively frequent model monitoring can increase DL (downlink) reference signal (RS) overhead and increase the measurement burden on the terminal, which can lead to battery drain. To address this, the disclosure of this specification efficiently performs model monitoring using one or more model monitoring cycles, thereby effectively resolving the trade-off between the DL RS overhead and measurement burden associated with model monitoring and model performance monitoring.

[0015] Figure 1 is a diagram illustrating a wireless communication system.

[0016] Figure 2 illustrates the structure of a radio frame used in NR.

[0017] Figures 3a to 3c are exemplary diagrams showing exemplary architectures for wireless communication services.

[0018] Figure 4 illustrates the slot structure of an NR frame.

[0019] Figure 5 illustrates an example of subframe types in NR.

[0020] Figure 6 illustrates the structure of a self-contained slot.

[0021] Figure 7 shows an example of initial beam measurement and selection in NR.

[0022] Figure 8 shows an example of an initial connection procedure between a terminal and a base station in NR.

[0023] Figure 9 shows an example of candidate beam settings in NR.

[0024] Figures 10a to 10c illustrate three procedures for beam management in NR.

[0025] Figures 11a to 11c illustrate examples of beam reporting procedures in NR.

[0026] Fig. 12 is a flowchart illustrating a method of operating a terminal according to one embodiment of the present specification.

[0027] FIG. 13 is an example showing multi-level model monitoring according to one embodiment of the present specification.

[0028] FIG. 14 is an example showing a model monitoring period change based on L1 / L2 signaling according to one embodiment of the present specification.

[0029] Fig. 15 is a flowchart illustrating a method of operating a terminal according to another embodiment of the present specification.

[0030] Fig. 16 is a flowchart illustrating an operation method of a base station according to one embodiment of the present specification.

[0031] Figure 17 illustrates a device according to one embodiment of the present specification.

[0032] Fig. 18 is a block diagram showing the configuration of a terminal according to one embodiment of the present specification.

[0033] Figure 19 shows a block diagram of a processor in which the disclosure of this specification is implemented.

[0034] FIG. 20 is a block diagram showing in detail the transmitter / receiver of the first device illustrated in FIG. 17 or the transmitter / receiver unit of the device illustrated in FIG. 18.

[0035] It should be noted that the technical terms used in this specification are used merely to describe specific embodiments and are not intended to limit the contents of this specification. In addition, unless specifically defined otherwise herein, the technical terms used in this specification should be interpreted as having a meaning generally understood by those skilled in the art to which this specification pertains, and should not be interpreted in an excessively broad or narrow sense. In addition, if a technical term used in this specification is an incorrect technical term that does not accurately express the contents and ideas of this specification, it should be replaced with a technical term that can be correctly understood by a person skilled in the art. In addition, general terms used in this specification should be interpreted according to their dictionary definitions or according to the preceding and following context, and should not be interpreted in an excessively narrow sense.

[0036] Additionally, the singular expressions used herein include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consist of" or "have" should not be construed to necessarily include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0037] Additionally, terms including ordinal numbers, such as "first" and "second," used herein may be used to describe various components, but these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a second component, and similarly, a second component could also be referred to as a first component.

[0038] When a component is referred to as being connected or connected to another component, it may be directly connected or connected to that other component, but there may also be other components intervening. Conversely, when a component is referred to as being directly connected or connected to another component, it should be understood that there are no other components intervening.

[0039] Hereinafter, embodiments will be described in detail with reference to the attached drawings. Regardless of the drawing reference numerals, identical or similar components will be given the same reference numerals, and redundant descriptions thereof will be omitted. In addition, when describing the contents of this specification, if a detailed description of a related known technology is judged to obscure the gist of this specification, the detailed description thereof will be omitted. In addition, it should be noted that the attached drawings are only intended to make the contents and ideas of this specification easily understandable, and should not be construed as limiting the contents and ideas of this specification by the attached drawings. The contents and ideas of this specification should be construed to extend to all changes, equivalents, and substitutes other than the attached drawings.

[0040] In this specification, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, “A or B” in this specification can be interpreted as “A and / or B.” For example, “A, B or C” in this specification can mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.”

[0041] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0042] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0043] Additionally, in this specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0044] Additionally, parentheses used in this specification may mean “for example.” Specifically, when “control information (PDCCH)” is indicated, “PDCCH (Physical Downlink Control Channel)” may be suggested as an example of “control information.” In other words, “control information” in this specification is not limited to “PDCCH,” and “PDDCH” may be suggested as an example of “control information.” Furthermore, even when indicated as “control information (i.e., PDCCH),” “PDCCH” may be suggested as an example of “control information.”

[0045] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0046] Although the attached drawing illustrates a UE (User Equipment) as an example, the illustrated UE may also be referred to as a terminal, ME (Mobile Equipment), etc. In addition, the UE may be a portable device such as a laptop, mobile phone, PDA, smart phone, multimedia device, etc., or a non-portable device such as a PC or vehicle-mounted device.

[0047] Hereinafter, the term "UE" is used as an example of a device capable of wireless communication (e.g., a wireless communication device, a wireless device, or a wireless device). The operations performed by the UE can be performed by any device capable of wireless communication. A device capable of wireless communication may also be referred to as a wireless communication device, a wireless device, or a wireless device.

[0048] The term base station used below generally refers to a fixed station that communicates with wireless devices, and can be used as a comprehensive term that includes eNodeB (evolved-NodeB), eNB (evolved-NodeB), BTS (Base Transceiver System), Access Point, gNB (Next generation NodeB), RRH (remote radio head), TP (transmission point), RP (reception point), relay, etc.

[0049] Although this specification describes embodiments using LTE systems, LTE-A systems, and NR systems, these embodiments may be applied to any communication system falling within the above definitions.

[0050] Wireless Communication System

[0051] Building on the success of LTE (long term evolution) / LTE-Advanced (LTE-A) for 4th generation mobile communications, commercialization of the next generation, or 5th generation (so-called 5G) mobile communications, and follow-up research are also ongoing.

[0052] The International Telecommunication Union (ITU) defines 5G mobile communications as providing data transfer speeds of up to 20 Gbps and a perceived transmission speed of at least 100 Mbps everywhere. Its official name is "IMT-2020."

[0053] ITU proposes three usage scenarios: eMBB (enhanced Mobile BroadBand), mMTC (massive Machine Type Communication), and URLLC (Ultra Reliable and Low Latency Communications).

[0054] URLLC addresses usage scenarios that require high reliability and low latency. For example, services such as autonomous driving, factory automation, and augmented reality require high reliability and low latency (e.g., sub-1ms). Current 4G (LTE) latency is statistically 21-43ms (best 10%) and 33-75ms (median). This is insufficient to support services requiring sub-1ms latency. Next, eMBB usage scenarios address usage scenarios that require mobile ultra-wideband.

[0055] In other words, the 5th generation mobile communication system can support higher capacity than the current 4G LTE, increase the density of mobile broadband users, and support D2D (Device to Device), high reliability, and MTC (Machine-type communication). 5G research and development also aims for lower latency and lower battery consumption than 4G mobile communication systems to better implement the Internet of Things. For this 5G mobile communication, a new radio access technology (New RAT or NR) may be proposed.

[0056] The NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges (FR1, FR2) can be as shown in Table 1 below. For convenience of explanation, 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).

[0057] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0058] The numerical value of the frequency range of the NR system can be changed. For example, FR1 can include a band from 410 MHz to 7125 MHz, as shown in Table 1. That is, FR1 can include frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 can include unlicensed bands. Unlicensed bands can be used for various purposes, such as for communications for vehicles (e.g., autonomous driving).

[0059] Meanwhile, 3GPP-based communication standards define downlink physical channels corresponding to resource elements that carry information originating from upper layers, and downlink physical signals corresponding to resource elements that are used by the physical layer but do not carry information originating from upper layers. For example, the physical downlink shared channel (PDSCH), physical broadcast channel (PBCH), physical multicast channel (PMCH), physical control format indicator channel (PCFICH), physical downlink control channel (PDCCH), and physical hybrid ARQ indicator channel (PHICH) are defined as downlink physical channels, and reference signals and synchronization signals are defined as downlink physical signals. A reference signal (RS), also referred to as a pilot, is a signal with a special predefined waveform known to the gNB and the UE. For example, cell specific RS, UE-specific RS (UE-RS), positioning RS (PRS), and channel state information RS (CSI-RS) are defined as downlink reference signals. The 3GPP LTE / LTE-A standard defines uplink physical channels corresponding to resource elements carrying information originating from higher layers, and uplink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers.For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH) are defined as uplink physical channels, and a demodulation reference signal (DMRS) for uplink control / data signals and a sounding reference signal (SRS) used for uplink channel measurement are defined.

[0060] In this specification, PDCCH (Physical Downlink Control CHannel) / PCFICH (Physical Control Format Indicator CHannel) / PHICH ((Physical Hybrid automatic retransmit request Indicator CHannel) / PDSCH (Physical Downlink Shared CHannel) mean a set of time-frequency resources or a set of resource elements that carry DCI (Downlink Control Information) / CFI (Control Format Indicator) / downlink ACK / NACK (ACKnowlegement / Negative ACK) / downlink data, respectively. In addition, PUCCH (Physical Uplink Control CHannel) / PUSCH (Physical Uplink Shared CHannel) / PRACH (Physical Random Access CHannel) mean a set of time-frequency resources or a set of resource elements that carry UCI (Uplink Control Information) / uplink data / random access signals, respectively.

[0061] Figure 1 is a diagram illustrating a wireless communication system.

[0062] As can be seen from FIG. 1, the wireless communication system includes at least one base station (BS). The BS is divided into a gNodeB (or gNB) (20a) and an eNodeB (or eNB) (20b). The gNB (20a) supports 5th generation mobile communications. The eNB (20b) supports 4th generation mobile communications, i.e., long term evolution (LTE).

[0063] Each base station (20a and 20b) provides communication services for a specific geographic area (commonly referred to as a cell) (20-1, 20-2, 20-3). The cell may be further divided into multiple areas (referred to as sectors).

[0064] A UE (user equipment) typically belongs to a single cell, and the cell to which the UE belongs is called a serving cell. The base station that provides communication services for the serving cell is called a serving base station (BS). Since the wireless communication system is a cellular system, there are other cells adjacent to the serving cell. These other cells adjacent to the serving cell are called neighbor cells. The base station that provides communication services to the neighbor cell is called a neighbor BS. The serving cell and neighbor cells are determined relative to the UE.

[0065] Hereinafter, downlink refers to communication from a base station (20) to a UE (10), and uplink refers to communication from a UE (10) to a base station (20). In downlink, the transmitter may be part of the base station (20), and the receiver may be part of the UE (10). In uplink, the transmitter may be part of the UE (10), and the receiver may be part of the base station (20).

[0066] Meanwhile, wireless communication systems can be broadly divided into frequency division duplex (FDD) and time division duplex (TDD). In FDD, uplink and downlink transmissions occupy different frequency bands and occur at different times. In TDD, uplink and downlink transmissions occupy the same frequency band but occur at different times. The channel response in TDD is essentially reciprocal, meaning that the downlink and uplink channel responses are nearly identical in a given frequency range. Therefore, in TDD-based wireless communication systems, the downlink channel response can be derived from the uplink channel response. In TDD, uplink and downlink transmissions are time-divided across the entire frequency band, so downlink transmission by the base station and uplink transmission by the UE cannot be performed simultaneously. In TDD systems, where uplink and downlink transmissions are divided into subframes, uplink and downlink transmissions are performed in different subframes.

[0067] Figure 2 illustrates the structure of a radio frame used in NR.

[0068] In NR, uplink and downlink transmissions are structured as frames. A radio frame is 10ms long and is defined by two 5ms half-frames (HF). Each half-frame is defined by five 1ms subframes (SF). A subframe is divided into one or more slots, and the number of slots in a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM(A) symbols, depending on the cyclic prefix (CP). When a normal CP is used, each slot contains 14 symbols. When an extended CP is used, each slot contains 12 symbols. Here, the symbols may include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or DFT-s-OFDM symbols).

[0069] Support for various numerologies

[0070] In NR systems, multiple numerologies may be provided to terminals as wireless communication technologies advance. For example, an SCS of 15 kHz supports a wide area in traditional cellular bands. An SCS of 30 kHz / 60 kHz supports dense urban environments, lower latency, and wider carrier bandwidth. An SCS of 60 kHz or higher supports a bandwidth greater than 24.25 GHz to overcome phase noise.

[0071] The above numerology can be defined by the cycle prefix (CP) length and subcarrier spacing (SCS). A single cell can provide multiple numerologies to a terminal. When the numerology index is represented by μ, each subcarrier spacing and the corresponding CP length can be as shown in the table below.

[0072] μ△f=2 μ 15 [kHz]CP015 General 130 General 260 General, Extended 3120 General 4240 General 5480 General 6960 General

[0073] For general CP, when the index of the numerology is represented by μ, the number of OFDM symbols per slot (N slot symb ), number of slots per frame (N frame,μ slot ) and the number of slots per subframe (N subframe,μ slot ) is as shown in the table below.

[0074] μ△f=2 μ 15 [kHz]N slot symb N frame,μ slot N subframe,μ slot 015141011301420226014404312014808424014160165480143203269601464064

[0075] For extended CP, when the index of the numerology is represented by μ, the number of OFDM symbols per slot (N slot symb ), number of slots per frame (N frame,μ slot ) and the number of slots per subframe (N subframe,μ slot ) is as shown in the table below.

[0076] μSCS (15*2 u )N slot symb N frame,μ slot N subframe,μslot 260KHz (u=2)12404

[0077] In an NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0078] Figures 3a to 3c are exemplary diagrams showing exemplary architectures for wireless communication services.

[0079] Referring to FIG. 3a, the UE is connected to an LTE / LTE-A-based cell and an NR-based cell in a DC (dual connectivity) manner.

[0080] The above NR-based cell is connected to the core network for existing 4th generation mobile communication, i.e. Evolved Packet Core (EPC).

[0081] Referring to FIG. 3b, unlike FIG. 3a, the LTE / LTE-A-based cell is connected to a core network for 5th generation mobile communication, i.e., a 5G core network.

[0082] A service method based on an architecture as illustrated in Figures 3a and 3b above is called NSA (non-standalone).

[0083] Referring to Figure 3c, the UE is connected only to NR-based cells. A service method based on this architecture is called SA (standalone).

[0084] Meanwhile, in the above NR, it may be considered that reception from the base station utilizes a downlink subframe, and transmission to the base station utilizes an uplink subframe. This method can be applied to paired and unpaired spectrums. A pair of spectrums means that two carrier spectrums are included for downlink and uplink operations. For example, in a pair of spectrums, one carrier may include a downlink band and an uplink band that are paired with each other.

[0085] Figure 4 illustrates the slot structure of an NR frame.

[0086] A slot contains multiple symbols in the time domain. For example, in the case of a normal CP, one slot contains 14 symbols, but in the case of an extended CP, one slot contains 12 symbols. A carrier contains multiple subcarriers in the frequency domain. An RB (Resource Block) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) is defined as multiple consecutive (physical, P)RBs in the frequency domain, and can correspond to a single numerology (e.g., SCS, CP length, etc.). A terminal can be configured with up to N (e.g., 4) BWPs in the downlink and uplink, respectively. Downlink or uplink transmission is performed through an activated BWP, and at a given time, only one BWP among the BWPs configured for the terminal can be activated. In the resource grid, each element is referred to as a Resource Element (RE), to which one complex symbol can be mapped.

[0087] Figure 5 illustrates an example of subframe types in NR.

[0088] The transmission time interval (TTI) illustrated in FIG. 5 may be referred to as a subframe or slot for NR (or new RAT). The subframe (or slot) of FIG. 5 may be used in a TDD system of NR (or new RAT) to minimize data transmission delay. As illustrated in FIG. 5, a subframe (or slot) includes 14 symbols. The symbols in the front of the subframe (or slot) may be used for a downlink (DL) control channel, and the symbols in the back of the subframe (or slot) may be used for an uplink (UL) control channel. The remaining symbols may be used for DL ​​data transmission or UL data transmission. According to this subframe (or slot) structure, downlink transmission and uplink transmission may be sequentially performed in one subframe (or slot). Therefore, downlink data may be received within a subframe (or slot), and an uplink acknowledgment (ACK / NACK) may be transmitted within the subframe (or slot).

[0089] The structure of these subframes (or slots) can be called self-contained subframes (or slots).

[0090] Specifically, the first N symbols in a slot are used to transmit a DL control channel (hereinafter, DL control region), and the last M symbols in the slot can be used to transmit a UL control channel (hereinafter, UL control region). N and M are each integers greater than or equal to 0. A resource region (hereinafter, data region) between the DL control region and the UL control region can be used for DL ​​data transmission or UL data transmission. For example, a physical downlink control channel (PDCCH) can be transmitted in the DL control region, and a physical downlink shared channel (PDSCH) can be transmitted in the DL data region. A physical uplink control channel (PUCCH) can be transmitted in the UL control region, and a physical uplink shared channel (PUSCH) can be transmitted in the UL data region.

[0091] Using this subframe (or slot) structure has the advantage of minimizing the final data transmission latency by reducing the time required to retransmit data that has experienced reception errors. In this self-contained subframe (or slot) structure, a time gap may be required during the transition from transmit mode to receive mode or from receive mode to transmit mode. To this end, some OFDM symbols during the transition from DL to UL in the subframe structure can be designated as a guard period (GP).

[0092] Figure 6 illustrates the structure of a self-contained slot.

[0093] In an NR system, a frame is characterized by a self-contained structure in which a DL control channel, DL or UL data, and a UL control channel can all be included within a single slot. For example, the first N symbols within a slot can be used to transmit a DL control channel (hereinafter, referred to as a DL control region), and the last M symbols within a slot can be used to transmit a UL control channel (hereinafter, referred to as a UL control region). N and M are each integers greater than or equal to 0. The resource region (hereinafter, referred to as a data region) between the DL control region and the UL control region can be used for DL ​​data transmission or UL data transmission. As an example, the following configuration can be considered. Each section is listed in chronological order.

[0094] 1. DL only configuration

[0095] 2. UL only configuration

[0096] 3. Mixed UL-DL configuration

[0097] - DL area + GP (Guard Period) + UL control area

[0098] - DL control area + GP + UL area

[0099] DL area: (i) DL data area, (ii) DL control area + DL data area

[0100] UL domain: (i) UL data domain, (ii) UL data domain + UL control domain

[0101] In the DL control region, a PDCCH can be transmitted, and in the DL data region, a PDSCH can be transmitted. In the UL control region, a PUCCH can be transmitted, and in the UL data region, a PUSCH can be transmitted. In the PDCCH, downlink control information (DCI), for example, DL data scheduling information, UL data scheduling information, etc., can be transmitted. In the PUCCH, uplink control information (UCI), for example, ACK / NACK (Positive Acknowledgement / Negative Acknowledgement) information for DL ​​data, CSI (Channel State Information) information, SR (Scheduling Request), etc., can be transmitted. GP provides a time gap when a base station and a terminal switch from transmission mode to reception mode or when switching from reception mode to transmission mode. Some symbols at the time of switching from DL to UL within a subframe can be set as GP.

[0102] <NR에서 빔 관리(beam management)>

[0103] Current 3GPP NR beam management methods can be divided into the initial access phase and the cell connection establishment phase. A terminal performing the initial access procedure establishes its initial transmit / receive (Tx / Rx) beam through a random access procedure, i.e., the random access channel (RACH) procedure.

[0104] Figure 7 shows an example of initial beam measurement and selection in NR.

[0105] Referring to Fig. 7, in order to provide base station transmission beam (gNB Tx beam) settings to terminals (UE1 / UE2) without cell connection, the base station periodically and repeatedly transmits SSBs (synchronization signal blocks) with beams in different directions mapped. In addition, SSBs can be transmitted at 20ms cycles within 5ms. Specifically, the default value for initial cell selection can be 20ms.

[0106] A terminal can select a qualified SSB through signal measurement for periodically transmitted SSBs and transmit a PRACH (physical random access channel) preamble mapped to the selected SSB, thereby informing the base station of information about the selected Tx beam. For example, based on signal strength measurements, terminals at different locations, i.e., UE1, can select an SSB with an SSB index of 3, and UE2, can select an SSB with an SSB index of 9, and UE1 and UE2 can each transmit a corresponding PRACH preamble for the selected SSB. Here, it is assumed that each SSB is beamformed in a specific direction.

[0107] Figure 8 shows an example of an initial connection procedure between a terminal and a base station in NR.

[0108] Referring to Fig. 8, after the terminal (UE) is powered on (S801), the UE receives cell-related parameter information (e.g., PRACH information corresponding to each SSB) required in the initial access phase through a system information message transmitted by the base station (gNB) (S802). Here, the system information message includes a master information block (MIB) and a system information block 1 (SIB1) including cell common information.

[0109] After acquiring the system information message, the terminal receives SSBs periodically transmitted from the base station (S803). Then, the terminal measures the RSRP (reference signal received power) for the received SSBs. Among the N SSBs, i.e., beams, the one SSB (beam) with the highest / qualified value is selected (S804).

[0110] Thereafter, the terminal transmits an RA (random access) preamble belonging to the PRACH resource corresponding to the selected SSB (beam) to the base station (S805). Through this, the terminal can inform the base station of the selected initial beam information.

[0111] The base station receives a RA (random access) preamble belonging to a PRACH resource corresponding to the SSB (beam) selected from the terminal, and in response transmits a RAR (random access response) to the terminal using the selected SSB (beam) (S806).

[0112] Meanwhile, a base station that does not know the location / beam information of a terminal that first enters a cell, i.e. a terminal performing a CBRA (contention based random access) procedure, can set up to 64 beams in common with the cell to set the beam of a terminal that has no connection, and the terminal sequentially measures all beams to find the optimal beam at its location. This not only causes a time delay in beam selection and cell connection as the number of beams in the cell increases, but can also increase the power consumption of the terminal by requiring the terminal to measure a large number of beams.

[0113] To address the aforementioned issues, the base station can map a wide beam for SSB to determine the approximate location / beam of the initially connected terminal, and then perform beam refinement to configure a narrow beam after the terminal accesses the cell. However, while a narrow beam provides a high data rate to the terminal, it is sensitive to the terminal's movement or environmental changes, which can easily cause disconnections. To address this, the base station allocates a CSI resource (CSI-RS / SSB) with a candidate beam mapped to the terminal in a UE-specific manner, allowing the terminal to continuously measure the surrounding beam strength and report the measurement results to the base station. This can be configured by the base station through CSI resource configuration and CSI report configuration.

[0114] Figure 9 shows an example of candidate beam settings in NR.

[0115] A terminal that has been configured for beam reporting performs measurement of the reference signal (RS) assigned to it and reports the result based on the configuration of the base station. This follows the CSI framework defined by 3GPP. However, this UE-specific CSI configuration method has a problem in that as the number of terminals in the cell increases, the RS resources allocated to each terminal also increase rapidly. To alleviate this resource overhead problem, the base station can select a method of allocating the same candidate beam, i.e., CSI resources, to terminals in similar locations, as shown in FIG. 9. This can be referred to as UE group-specific CSI resource configuration. However, when terminals with different mobility share the same resource, an issue arises in which new candidate beam resources must be allocated to terminals that leave the corresponding resource area. If a minimum number of candidate beams is allocated to a UE with high / medium mobility to reduce resource overhead, the UE will experience frequent RRC reconfigurations. These candidate beam reconfigurations through RRC incur relatively large delays, potentially leading to beam dropouts. To mitigate this issue, the base station can operate candidate beams by appropriately increasing the number of beams within the CSI resource set. However, from the UE's perspective, this may present a trade-off: the increased number of beams increases the measurement burden.

[0116] Figures 10a to 10c illustrate three procedures for beam management in NR.

[0117] Beam management in NR can be defined by dividing it into three procedures in terms of the procedures defined in the physical layer. Fig. 10a shows Procedure 1 (P1), Fig. 10b shows Procedure 2 (P2), and Fig. 10c shows Procedure 3 (P3), respectively. P1 is an operation to find a transmit / receive beam pair while simultaneously performing TRP (transmission reception point) beam sweeping and UE beam sweeping, similar to the beam setting method of a terminal performing the initial access procedure described above. A terminal that enters connected mode recognizes that the beams set by the base station through candidate beam (i.e., CSI resource set) setting will be swept, and first performs signal strength measurement for the TRP beam. When the terminal's TRP beam is selected through P2, the base station repeatedly transmits the selected one beam through P3. A terminal can select a UE beam while performing UE beam sweeping. The UE's choice of beam during this operation is left to the terminal implementation. The aforementioned operation can be applied to both downlink (DL) and uplink (UL).

[0118] Figures 11a to 11c illustrate examples of beam reporting procedures in NR.

[0119] Beam sweeping uses a method in which the base station notifies the terminal of reference signal (RS) resource information by configuring a specific candidate beam, i.e., a CSI resource set, so that information about the beam is implicitly provided by being mapped to the RS resource information. In other words, rather than notifying the terminal of the actual beam index, the base station recognizes the information about the mapped beam through the index information implicitly mapped to the RS information using the RS resource indicator (RI). This is configured using the 3GPP CSI framework, and the terminal implicitly reports RSRP information for the best four beams (RI) to the base station by measuring the RS strength for the resources configured by the base station. The method for reporting the measurement results also depends on the RRC configuration of the base station, and 3GPP defines one of the following three methods to be configured.

[0120] - Periodic reporting

[0121] - Aperiodic reporting

[0122] - Semi-persistent reporting

[0123] Figure 11a illustrates a periodic CSI reporting method, which is triggered through RRC configuration. That is, the terminal receives an RRC configuration message from the base station, and the RRC configuration message includes settings for CSI-related RS resources and reporting methods, i.e., CSI resource set information, and information that CSI reporting is periodic (S1101a). Thereafter, the terminal receives RSs periodically transmitted based on the received RRC configuration message (S1102a and S1105a), and measures the signal strength for a beam based on the received RSs (S1103a and S1106a). Then, the terminal periodically reports the measured results (values) to the base station (S1104a and S1107a).

[0124] Figure 11b illustrates an aperiodic CSI reporting method. Even if CSI-related RS resources and a reporting method are configured through an RRC configuration message, beam measurement through RS is not performed without a trigger message (or information) from a lower layer. That is, the terminal receives an RRC configuration message including CSI resource set information and information that CSI reporting is aperiodic from the base station regarding configuration of CSI-related RS resources and a reporting method (i.e., CSI resource set information) and information that CSI reporting is aperiodic (S1101b), and the CSI report trigger is performed through a medium access control (MAC) control element (CE) or downlink control information (DCI). The terminal receives CSI report trigger information including a trigger indication from the base station through the MAC CE or DCI (S1102b), and receives RSs transmitted once based on the received trigger indication (S1103b). Here, the transmission of RSs for the CSI resource set can be transmitted after a specific time (e.g., X slots) at which the CSI report trigger information is transmitted. Thereafter, the terminal measures the signal strength for the beam based on the received RSs (S1104b). Then, the terminal reports the measured result (value) to the base station once (S1105b). Here, the CSI report can be transmitted after a specific time (e.g., Y slots) at which the CSI report trigger information is received.

[0125] Fig. 11c shows a semi-persistent reporting method, which is an intermediate method between the periodic reporting method and the aperiodic reporting method. Upon receiving a configuration for CSI-related RS resources and a reporting method through an RRC configuration message, the terminal performs CSI reporting periodically until receiving a deactivation message (or information) only when activated by MAC CE. That is, the terminal receives an RRC configuration message from the base station that includes a configuration for CSI-related RS resources and a reporting method, that is, CSI resource set information and information that CSI reporting is semi-persistent (S1101c), and CSI report activation is performed through MAC CE. The terminal receives CSI report activation information including an activation indication from the base station via MAC CE (S1102c and S1110c), receives RSs periodically transmitted based on the received activation indication (S1103c, S1106c, S1111c and S1114c), and measures signal strength for a beam based on the received RSs (S1104c, S1107c, S1112c and S1115c). Then, the terminal periodically reports the measured result (value) to the base station (S1105c, S1108c, S1113c and S1116c). After CSI reporting is activated, if CSI report deactivation information including a deactivation indication is received from the base station via MAC CE (S1109c), the terminal stops CSI reporting.

[0126] 3GPP is conducting research on technology that applies AI / ML models to improve delay and terminal power consumption in the aforementioned beam search (measurement).

[0127] The list of terms applied to AI / ML is discussed as shown in Table 5 below.

[0128] Terminology Description Data collection A process of collecting data by the network nodes, management entity, or UE for the purpose of AI / ML model training, data analytics and inference AI / ML Model A data driven algorithm that applies AI / ML techniques to generate a set of outputs based on a set of inputs.)AI / ML model trainingA process to train an AI / ML Model [by learning the input / output relationship] in a data driven manner and obtain the trained AI / ML Model for inference. AI / ML model inferenceA process of using a trained AI / ML model to produce a set of outputs based on a set of inputs. AI / ML model validationA subprocess of training to evaluate the quality of an AI / ML model using a dataset different from the one used for model training, that helps selecting model parameters that generalize beyond the dataset used for model training. AI / ML model testing Testing is a sub-process of training that evaluates the performance of the final AI / ML model using a dataset different from that used for model training and validation. Unlike AI / ML model validation, testing does not assume subsequent adjustments to the model.(A subprocess of training, to evaluate the performance of a final AI / ML model using a dataset different from one used for model training and validation. Differently from AI / ML model validation, testing does not assume subsequent tuning of the model.)UE-side (AI / ML) modelAn AI / ML Model whose inference is performed entirely at the UENetwork-side (AI / ML) modelAn AI / ML Model whose inference is performed entirely at the networkOne-sided (AI / ML) modelA UE-side (AI / ML) model or a Network-side (AI / ML) modelTwo-sided (AI / ML) modelA pair of AI / ML model(s) on which joint inference is performed. Here, joint inference is AI / ML inference where inference is performed jointly across the UE and the network, i.e., the first part of the inference is performed first by the UE and the remaining part by the gNB, or vice versa.(A paired AI / ML Model(s) over which joint inference is performed, where joint inference comprises AI / ML Inference whose inference is performed jointly across the UE and the network, i.e., the first part of inference is firstly performed by the UE and then the remaining part is performed by gNB, or vice versa.)AI / ML model transferTransfer of an AI / ML model over a wireless interface with parameters of a model structure known to the receiving end or a new model having parameters. Delivery of an AI / ML model over the air interface, either parameters of a model structure known at the receiving end or a new model with parameters. Delivery may contain a full model or a partial model. Model download: Model transfer from the network to UE. Model upload: Model transfer from UE to the network. Federated learning / federated training: A machine learning technique for training an AI / ML model on multiple distributed edge nodes (e.g., UEs, gNBs), each performing local model training using local data samples. This technique requires multiple interactions of the model but does not require the exchange of local data samples.(A machine learning technique that trains an AI / ML model across multiple decentralized edge nodes (e.g., UEs, gNBs) each performing local model training using local data samples. The technique requires multiple interactions of the model, but no exchange of local data samples.) Offline field data: The data collected from the field and used for offline training of the AI / ML model. Online field data: The data collected from the field and used for online training of the AI / ML model. Model monitoring: A procedure that monitors the inference performance of the AI / ML model. Supervised learning: A process of training a model from input and its corresponding labels. Unsupervised learning: A process of training a model without labeled data.)Semi-supervised learning: A process of training a model with a mix of labeled and unlabeled data. Reinforcement Learning (RL): A process of training an AI / ML model from input (aka state) and a feedback signal (aka reward) resulting from the model's output (aka action) in an environment the model is interacting with.. Model activation: Enable an AI / ML model for a specific function. Model deactivation: Disable an AI / ML model for a specific function. Model switching: Deactivating a currently active AI / ML model and activating another AI / ML model for a specific function. a different AI / ML model for a specific function.

[0129] 3GPP RAN1 has been discussing model monitoring techniques for each use case and is considering it as one of the key factors for maintaining the performance of AI / ML models.

[0130] Current AI / ML models aim to improve overall system performance by applying model inference output to communication techniques to reduce DL (downlink) RS (reference signal) overhead and terminal measurement burden. Furthermore, they utilize models to obtain more accurate results, thereby improving overall system performance. To maintain consistent performance, these AI / ML models require continuous monitoring. Various metrics were identified as candidates for model monitoring during the previous study period, and the information reported from terminals to base stations can also vary depending on which node performs this performance monitoring.

[0131] As more detailed standardization discussions begin in the future, procedures related to AI / ML model monitoring on terminals are expected to be defined. The most intuitive way to evaluate model performance is through model accuracy. This requires comparing the output derived from model inference with the results of actual communication environments. Additional RS transmissions, which serve as benchmarks / references for model performance measurement, need to be defined in relation to the model inference time, but there is currently no specific discussion or definition for this. Furthermore, if benchmark / reference RSs are required for monitoring, excessively frequent transmission or measurement of these RSs can incur additional overhead for base stations and terminals, and if not monitored in a timely manner, this can degrade system performance. To address this trade-off, a method for efficiently performing monitoring is needed.

[0132] As a solution to the above, in this specification, when performing wireless communication between a base station and a terminal using an AI / ML model, a method is proposed in which at least one model monitoring period is set based on a DL RS period set for model inference for a benchmark / reference RS resource for measuring the performance of a model operating in the terminal or base station, and the period for model monitoring is adaptively changed based on the model performance results.

[0133] More specifically, when the base station configures DL RS resources for model inference for a terminal, it configures additional DL RS resources associated with the DL RS resources for model inference for the purpose of monitoring, and the DL RS resources for monitoring can have at least one or more periods. Here, the transmission period for the DL RS resources for monitoring can be set to a period(s) that is a multiple of n (where n is a natural number greater than 1) based on the transmission period of the DL RS resources for model inference.

[0134] Fig. 12 is a flowchart illustrating a method of operating a terminal according to one embodiment of the present specification.

[0135] When one or more model monitoring periods are set for a terminal, the base station clearly notifies the terminal of a change in the monitoring DL RS transmission period based on information received from the terminal (e.g., monitoring result or assistance information) or internal information of the base station, or defines that the terminal and the base station recognize the change in the monitoring DL RS transmission period based on an arbitrary condition (e.g., timer or count). If the change in the monitoring period is performed based on signaling, the configuration information for one or more monitoring periods proposed in the present invention is proposed to be transmitted through radio resource control (RRC) control information (or message), and an instruction for changing the monitoring period is proposed to be performed through signaling such as downlink control information (DCI) / uplink control information (UCI) or medium access control (MAC) control element (CE). Additionally, if a condition for changing the monitoring period and a parameter related thereto are set together, it is proposed to change the monitoring period if the set condition is satisfied.

[0136] Referring to FIG. 12, a terminal receives an RRC message from a base station, which includes DL RS resource information having at least one cycle for model monitoring (S1201). The terminal performs model monitoring for each first cycle based on the received information (S1202). The base station may determine a change in the monitoring DL RS transmission cycle, and may do so based on monitoring results or assistance information received from the terminal. If the base station determines to change the monitoring DL RS transmission cycle, it may indicate this to the terminal. That is, the terminal receives L1 / L2 signaling from the base station indicating a change in the monitoring DL RS transmission cycle to a second cycle (S1203). Thereafter, the terminal performs model monitoring for each second cycle (S1204).

[0137] FIG. 13 is an example showing multi-level model monitoring according to one embodiment of the present specification.

[0138] The monitoring cycle proposed in this specification may be set to at least one or more cycles (i.e., the 1st to Nth cycles) for each terminal / model / function as a multiple (N*x) of the inference cycle (x) for the corresponding model, as shown in Fig. 13. The terminal performs inference using the DL RS for model inference transmitted from the base station based on the inference cycle (x), and performs model monitoring using the DL RS for model monitoring transmitted from the base station based on the monitoring cycle (e.g., N*x).

[0139] If the terminal is configured with one or more monitoring periods via RRC, the terminal may start monitoring by setting the shortest period (e.g., 1st period) as the default model monitoring period or by explicitly receiving a default monitoring period instruction from the base station.

[0140] Referring to Fig. 13, if a terminal is set with n model monitoring periods, the terminal starts model monitoring with the indicated or default model monitoring period. Here, it is assumed that the 1st to Nth model monitoring periods are set in the order of the length of the period from the shortest period. When the terminal performs model monitoring from the first period, the base station and the terminal may want to change the model monitoring to a longer period depending on the model performance result value or any set condition. That is, when the model accuracy is sufficiently high according to the model monitoring result, or when the terminal's battery is low, or when the terminal's movement speed is low, and conditions do not require frequent monitoring, the terminal may change the monitoring period of the terminal to a longer period so that the terminal performs model monitoring intermittently. Conversely, when the terminal's movement speed is high, the terminal's battery is sufficient, or when the model's accuracy is low, and conditions require frequent model monitoring, the terminal may be made to perform model monitoring with a shorter period.

[0141] Below, we describe specific methods for changing the model monitoring cycle.

[0142] FIG. 14 is an example showing a model monitoring period change based on L1 / L2 signaling according to one embodiment of the present specification.

[0143] The base station can set one or more model monitoring cycles for the terminal through an RRC message (or information) and simultaneously set a method for reporting the monitoring results. In this case, if the monitoring results (i.e., monitoring DL RS measurement results or model performance results depending on the monitoring type) are set to be reported periodically to the base station each time monitoring is performed, the terminal reports the required results to the base station each time it measures DL RS for model monitoring. The base station can instruct the terminal to dynamically change the monitoring cycle of the terminal using L1 / L2 signaling based on the report received from the terminal. This means that the base station can quickly instruct the terminal to operate with one or more configured monitoring cycles using L1 / L2 signaling, such as DCI or MAC CE, to instruct the terminal to dynamically change the monitoring cycle of the terminal. The instructor can include an index or cycle information for the cycle configured for monitoring in the RRC message (or information), or can be instructed in the form of an n-bit long bitmap.

[0144] Meanwhile, L1 / L2 signaling can also be defined to be transmitted from the terminal to the base station. The terminal can transmit information about its preferred cycle to the base station, or request / indicate a change to the requested / preferred cycle. This can be done by requesting / indicating a change to the requested / preferred cycle using L1 / L2 signaling such as UCI or MAC CE, or by transmitting preferred cycle information to the base station using an RRC message (or information) that carries assistance information. The indicator can include an index or cycle information for the cycle set for monitoring in the RRC message (or information), or can be indicated in the form of an n-bit long bitmap. The base station that receives this can change the model monitoring cycle of the terminal based on the received information, or instruct a change by transmitting L1 / L2 response signaling (i.e., DCI / MAC CE) for the change.

[0145] Hereinafter, terminal operation is described in detail with reference to FIG. 14.

[0146] The terminal receives an RRC message from the base station containing configuration information for DL ​​RS resources and reporting related to the AI / ML model. The message may include at least one of the following information:

[0147] - DL RS resource and reporting method configuration information for AI / ML model inference. This may include inference cycle (e.g., x slots) configuration information.

[0148] - DL RS resource and reporting method configuration information for AI / ML model monitoring associated with AI / ML model inference. Here, at least one monitoring cycle (e.g., x slots and 2x slots) configuration information may be included.

[0149] The terminal performs inference and monitoring every x slots based on the received RRC message.

[0150] Afterwards, the terminal reports the results of inference and monitoring to the base station.

[0151] The terminal receives L1 or L2 signaling from the base station indicating a change in the model monitoring period. Here, the indication of a change in the model monitoring period means an indication of changing the model monitoring period to 2x slots.

[0152] The terminal performs inference every x slots based on the received L1 / L2 signaling, and performs model monitoring every 2x slots.

[0153] Below, the operation of the base station is described in detail with reference to FIG. 14.

[0154] The base station transmits an RRC message to the terminal containing configuration information for DL ​​RS resources and reporting related to the AI / ML model. The message may include at least one of the following information:

[0155] - DL RS resource and reporting method configuration information for AI / ML model inference. This may include inference cycle (e.g., x slots) configuration information.

[0156] - DL RS resource and reporting method configuration information for AI / ML model monitoring associated with AI / ML model inference. Here, at least one monitoring cycle (e.g., x slots and 2x slots) configuration information may be included.

[0157] The base station transmits DL RS for inference and monitoring every x slots based on the transmitted RRC message.

[0158] Afterwards, the base station receives the results of inference and monitoring from the terminal.

[0159] The base station decides to change the model monitoring cycle of the terminal based on the performance results and internal condition information received from the terminal, and transmits L1 or L2 signaling indicating this.

[0160] The base station transmits DL RS for inference every x slots based on the transmitted L1 / L2 signaling, and DL RS for model monitoring every 2x slots.

[0161] Fig. 15 is a flowchart illustrating a method of operating a terminal according to another embodiment of the present specification.

[0162] Referring to FIG. 15, the terminal receives first configuration information for performance monitoring of an AI / ML model from a base station (S1501). The first configuration information may include information about a first reference signal (RS) resource and at least one monitoring cycle associated with the first reference signal resource.

[0163] The terminal performs performance monitoring of the AI / ML model based on the first monitoring cycle among at least one monitoring cycle (S1502).

[0164] Thereafter, the terminal receives a signal from the base station indicating a change to a second monitoring cycle among at least one monitoring cycle (S1503), and performs performance monitoring of the AI / ML model based on the second monitoring cycle (S1504).

[0165] Meanwhile, the terminal may receive second configuration information for AI / ML model inference from the base station. The second configuration information may include information about a second reference signal resource and an inference cycle associated with the second reference signal resource. Based on the inference cycle, the terminal may perform AI / ML model inference. Furthermore, the terminal may transmit the AI / ML model inference results and performance monitoring results to the base station.

[0166] The first setting information and the second setting information are received via an RRC (radio resource control) message, and the signaling may be L1 (layer 1) signaling or L2 (layer 2) signaling.

[0167] Preferably, at least one monitoring period can be set to a multiple of the inference period.

[0168] Fig. 16 is a flowchart illustrating an operation method of a base station according to one embodiment of the present specification.

[0169] Referring to FIG. 16, the base station transmits first configuration information for performance monitoring of an AI / ML model to the terminal (S1601). The first configuration information may include information on a first reference signal (RS) resource and at least one monitoring cycle associated with the first reference signal resource.

[0170] The base station transmits a first reference signal based on a first monitoring period among at least one monitoring period (S1602).

[0171] Thereafter, the base station transmits to the terminal a signal indicating a change to a second monitoring cycle among at least one monitoring cycle (S1603), and transmits a first reference signal based on the second monitoring cycle (S1604).

[0172] Meanwhile, the base station may transmit second configuration information to the terminal for AI / ML model inference. The second configuration information may include information about a second reference signal resource and an inference period associated with the second reference signal resource. The base station may transmit the second reference signal based on the inference period. Furthermore, the base station may receive AI / ML model inference results and performance monitoring results from the terminal.

[0173] The first setting information and the second setting information are received via an RRC (radio resource control) message, and the signaling may be L1 (layer 1) signaling or L2 (layer 2) signaling.

[0174] Preferably, at least one monitoring period can be set to a multiple of the inference period.

[0175] The concepts disclosed in this specification may be applied independently or may be combined and operated in any form. Furthermore, while this specification is based on a 5G NR system, the scope of this specification encompasses all cases in which the concepts of this specification apply, regardless of the specific wireless communication technology.

[0176] Figure 17 illustrates a device according to one embodiment of the present specification.

[0177] Referring to FIG. 17, the wireless communication system may include a first device (100a) and a second device (100b).

[0178] The first device (100a) may be a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or any other device related to the 4th industrial revolution field.

[0179] The second device (100b) may be a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or any other device related to the 4th industrial revolution field.

[0180] The first device (100a) may include at least one processor, such as a processor (1020a), at least one memory, such as a memory (1010a), and at least one transceiver, such as a transceiver (1031a). The processor (1020a) may perform the functions, procedures, and / or methods described above. The processor (1020a) may perform one or more protocols. For example, the processor (1020a) may perform one or more layers of a wireless interface protocol. The memory (1010a) may be connected to the processor (1020a) and may store various types of information and / or commands. The transceiver (1031a) may be connected to the processor (1020a) and may be controlled to transmit and receive wireless signals.

[0181] The second device (100b) may include at least one processor, such as a processor (1020b), at least one memory device, such as a memory (1010b), and at least one transceiver, such as a transceiver (1031b). The processor (1020b) may perform the functions, procedures, and / or methods described above. The processor (1020b) may implement one or more protocols. For example, the processor (1020b) may implement one or more layers of a wireless interface protocol. The memory (1010b) may be connected to the processor (1020b) and may store various types of information and / or commands. The transceiver (1031b) may be connected to the processor (1020b) and may be controlled to transmit and receive wireless signals.

[0182] The memory (1010a) and / or the memory (1010b) may be connected internally or externally to the processor (1020a) and / or the processor (1020b), or may be connected to another processor via various technologies such as a wired or wireless connection.

[0183] The first device (100a) and / or the second device (100b) may have one or more antennas. For example, the antenna (1036a) and / or the antenna (1036b) may be configured to transmit and receive wireless signals.

[0184] Fig. 18 is a block diagram showing the configuration of a terminal according to one embodiment of the present specification.

[0185] In particular, FIG. 18 is a drawing illustrating the device of FIG. 17 in more detail.

[0186] The device includes a memory (1010), a processor (1020), a transceiver (1031), a power management module (1091), a battery (1092), a display (1041), an input unit (1053), a speaker (1042), and a microphone (1052), a subscriber identification module (SIM) card, and one or more antennas.

[0187] The processor (1020) may be configured to implement the proposed functions, procedures, and / or methods described herein. Layers of a radio interface protocol may be implemented in the processor (1020). The processor (1020) may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. The processor (1020) may be an application processor (AP). The processor (1020) may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). Examples of the processor (1020) may be a SNAPDRAGON™ series processor manufactured by Qualcomm®, an EXYNOSTM series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO™ series processor manufactured by MediaTek®, an ATOM™ series processor manufactured by INTEL®, a KIRINTM series processor manufactured by HiSilicon®, or a corresponding next-generation processor.

[0188] The power management module (1091) manages power to the processor (1020) and / or the transceiver (1031). The battery (1092) supplies power to the power management module (1091). The display (1041) outputs the results processed by the processor (1020). The input unit (1053) receives input to be used by the processor (1020). The input unit (1053) can be displayed on the display (1041). A SIM card is an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and its associated keys, which are used to identify and authenticate subscribers in mobile devices such as mobile phones and computers. Contact information can also be stored on many SIM cards.

[0189] The memory (1010) is operably coupled to the processor (1020) and stores various information for operating the processor (610). The memory (1010) may include a read-only memory (ROM), a random access memory (RAM), flash memory, a memory card, a storage medium, and / or other storage devices. When the embodiment is implemented in software, the techniques described herein may be implemented as modules (e.g., procedures, functions, etc.) that perform the functions described herein. The modules may be stored in the memory (1010) and executed by the processor (1020). The memory (1010) may be implemented within the processor (1020). Alternatively, the memory (1010) may be implemented external to the processor (1020) and communicatively connected to the processor (1020) via various means known in the art.

[0190] The transceiver (1031) is operably coupled to the processor (1020) and transmits and / or receives a radio signal. The transceiver (1031) includes a transmitter and a receiver. The transceiver (1031) may include baseband circuitry for processing a radio frequency signal. The transceiver controls one or more antennas to transmit and / or receive a radio signal. The processor (1020) transmits command information to the transceiver (1031) to initiate communication, for example, to transmit a radio signal constituting voice communication data. The antenna functions to transmit and receive radio signals. Upon receiving a radio signal, the transceiver (1031) may transmit the signal to the processor (1020) for processing and convert the signal to baseband. The processed signal may be converted into audible or readable information output through the speaker (1042).

[0191] The speaker (1042) outputs sound-related results processed by the processor (1020). The microphone (1052) receives sound-related input to be used by the processor (1020).

[0192] A user inputs command information, such as a phone number, for example, by pressing (or touching) a button on an input unit (1053) or by voice activation using a microphone (1052). The processor (1020) receives this command information and processes it to perform an appropriate function, such as dialing a phone number. Operational data can be extracted from a SIM card or memory (1010). In addition, the processor (1020) can display command information or operation information on a display (1041) for the user's recognition and convenience.

[0193] Figure 19 shows a block diagram of a processor in which the disclosure of this specification is implemented.

[0194] As can be seen from FIG. 19, the processor (1020) implementing the disclosure of the present specification may include multiple circuits to implement the proposed functions, procedures, and / or methods described herein. For example, the processor (1020) may include a first circuit (1020-1), a second circuit (1020-2), and a third circuit (1020-3). Furthermore, although not shown, the processor (1020) may include more circuits. Each circuit may include multiple transistors.

[0195] The above processor (1020) may be called an application-specific integrated circuit (ASIC) or an application processor (AP), and may include at least one of a digital signal processor (DSP), a central processing unit (CPU), and a graphics processing unit (GPU).

[0196] FIG. 20 is a block diagram showing in detail the transmitter / receiver of the first device illustrated in FIG. 17 or the transmitter / receiver unit of the device illustrated in FIG. 18.

[0197] Referring to FIG. 20, the transceiver (1031) includes a transmitter (1031-1) and a receiver (1031-2). The transmitter (1031-1) includes a DFT (Discrete Fourier Transform) unit (1031-11), a subcarrier mapper (1031-12), an IFFT unit (1031-13), a CP insertion unit (1031-14), and a wireless transmitter (1031-15). The transmitter (1031-1) may further include a modulator. In addition, for example, the transmitter may further include a scramble unit (not shown), a modulation mapper (not shown), a layer mapper (not shown), and a layer permutator (not shown), which may be arranged before the DFT unit (1031-11). That is, in order to prevent an increase in PAPR (peak-to-average power ratio), the transmitter (1031-1) first passes the information through a DFT (1031-11) before mapping the signal to a subcarrier. The signal spread (or precoded in the same sense) by the DFT unit (1031-11) is mapped to a subcarrier through a subcarrier mapper (1031-12) and then passes through an IFFT (Inverse Fast Fourier Transform) unit (1031-13) to be converted into a signal on the time axis.

[0198] The DFT unit (1031-11) performs DFT on the input symbols and outputs complex-valued symbols. For example, if Ntx symbols are input (where Ntx is a natural number), the DFT size is Ntx. The DFT unit (1031-11) may be called a transform precoder. The subcarrier mapper (1031-12) maps the complex symbols to each subcarrier in the frequency domain. The complex symbols may be mapped to resource elements corresponding to resource blocks allocated for data transmission. The subcarrier mapper (1031-12) may be called a resource element mapper. The IFFT unit (1031-13) performs IFFT on the input symbols and outputs a baseband signal for data, which is a time-domain signal. The CP insertion unit (1031-14) copies a portion of the rear portion of the baseband signal for data and inserts it into the front portion of the baseband signal for data. CP insertion prevents ISI (Inter-Symbol Interference) and ICI (Inter-Carrier Interference), thereby maintaining orthogonality even in multipath channels.

[0199] On the other hand, the receiver (1031-2) includes a wireless reception unit (1031-21), a CP removal unit (1031-22), an FFT unit (1031-23), and an equalization unit (1031-24). The wireless reception unit (1031-21), the CP removal unit (1031-22), and the FFT unit (1031-23) of the receiver (1031-2) perform the inverse functions of the wireless transmission unit (1031-15), the CP insertion unit (1031-14), and the IFF unit (1031-13) of the transmitter (1031-1). The receiver (1031-2) may further include a demodulator.

[0200] Although the preferred embodiments have been described above by way of example, the disclosure of this specification is not limited to such specific embodiments, and may be modified, changed, or improved in various forms within the scope described in the spirit and claims of this specification.

[0201] In the exemplary system described above, the methods are described based on a flowchart as a series of steps or blocks. However, the order of the steps described is not limited, and some steps may occur in a different order or simultaneously with other steps described above. Furthermore, those skilled in the art will understand that the steps depicted in the flowchart are not exclusive, and other steps may be included, or one or more steps in the flowchart may be deleted without affecting the scope of the invention.

[0202] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

Claims

1. In a method of operating a terminal in a wireless communication system, A step of receiving first configuration information for performance monitoring of an AI (artificial intelligence) / ML (machine learning) model, wherein the first configuration information includes information on a first reference signal (RS) resource and at least one monitoring period associated with the first reference signal resource; A step of performing performance monitoring of the AI / ML model based on a first monitoring cycle among the at least one monitoring cycle; A step of receiving a signal indicating a change to a second monitoring period among at least one of the monitoring periods; and A method comprising the step of performing performance monitoring of the AI / ML model based on the second monitoring cycle.

2. In paragraph 1, A step of receiving second configuration information for inference of the AI / ML model, wherein the second configuration information includes information about a second reference signal resource and an inference period associated with the second reference signal resource; and A method further comprising a step of performing inference of the AI / ML model based on the above inference cycle.

3. In paragraph 2, A method further comprising the step of transmitting the inference results and performance monitoring results of the above AI / ML model.

4. In paragraph 2, A method wherein the first setting information and the second setting information are received via an RRC (radio resource control) message, and the signaling is L1 (layer 1) signaling or L2 (layer 2) signaling.

5. In paragraph 2, A method wherein at least one of the monitoring periods is set to a multiple of the inference period.

6. In a method of operating a base station in a wireless communication system, A step of transmitting first configuration information for performance monitoring of an AI (artificial intelligence) / ML (machine learning) model, wherein the first configuration information includes information on a first reference signal (RS) resource and at least one monitoring period associated with the first reference signal resource; A step of transmitting a first reference signal based on a first monitoring period among at least one of the above monitoring periods; A step of transmitting a signal indicating a change to a second monitoring cycle among at least one of the above monitoring cycles; and A method comprising the step of transmitting the first reference signal based on the second monitoring period.

7. In paragraph 6, A step of transmitting second configuration information for inference of the AI / ML model, wherein the second configuration information includes information about a second reference signal resource and an inference cycle associated with the second reference signal resource; and A method further comprising the step of transmitting a second reference signal based on the above inference cycle.

8. In paragraph 7, A method further comprising the step of receiving the inference results and performance monitoring results of the AI / ML model.

9. In paragraph 7, A method wherein the first setting information and the second setting information are transmitted via an RRC (radio resource control) message, and the signaling is L1 (layer 1) signaling or L2 (layer 2) signaling.

10. In paragraph 7, A method wherein at least one of the monitoring periods is set to a multiple of the inference period.

11. As a terminal in a wireless communication system, at least one processor; and At least one memory storing instructions and being operably electrically connected to said at least one processor, wherein the operations performed based on the instructions being executed by said at least one processor are: A step of receiving first configuration information for performance monitoring of an AI (artificial intelligence) / ML (machine learning) model, wherein the first configuration information includes information on a first reference signal (RS) resource and at least one monitoring period associated with the first reference signal resource. A step of performing performance monitoring of the AI / ML model based on a first monitoring cycle among at least one of the above monitoring cycles, A step of receiving a signal indicating a change to a second monitoring cycle among at least one of the above monitoring cycles, and A terminal comprising a step of performing performance monitoring of the AI / ML model based on the second monitoring cycle.

12. In paragraph 11, Based on the above instruction being executed by the at least one processor, the operations performed are: A step of receiving second configuration information for inference of the AI / ML model, wherein the second configuration information includes information about a second reference signal resource and an inference cycle associated with the second reference signal resource, and A terminal further comprising a step of performing inference of the AI / ML model based on the above inference cycle.

13. In paragraph 12, Based on the above instruction being executed by the at least one processor, the operations performed are: A terminal further comprising a step of transmitting the inference result and performance monitoring result of the AI / ML model.

14. In paragraph 12, A terminal, wherein the first setting information and the second setting information are received via an RRC (radio resource control) message, and the signaling is L1 (layer 1) signaling or L2 (layer 2) signaling.

15. In paragraph 12, A terminal wherein at least one of the above monitoring periods is set to a multiple of the above inference period.

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