Method and device pertaining to state measurement report using artificial intelligence and machine learning in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. The present disclosure relates to a method and device pertaining to a state measurement report using artificial intelligence and machine learning in a wireless communication system.

Description

Method and device for reporting status measurement using artificial intelligence and machine learning in wireless communication systems

[0001] The present invention relates to a method and device for status measurement reporting using artificial intelligence and machine learning in a wireless communication system.

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

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

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

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

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

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

[0008] As described above and with the development of mobile communication systems, various services have become available, and methods for providing these services effectively are required.

[0009] The present disclosure introduces a channel environment measurement and prediction method based on an AI / ML (artificial intelligence and machine learning) algorithm for implementing a preemptive handover algorithm in a high-density micro-cell environment and an environment with high mobility, and aims to improve the overall performance and stability of the network by reducing the overhead that may occur when reporting channel environment measurement and prediction.

[0010] The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0011] According to an embodiment of the present invention for solving the above-described problem, a method performed by a terminal of a wireless communication system may include the steps of: receiving a first message including L1 (layer 1) measurement prediction configuration information or L1 measurement logging configuration information from a base station; generating a prediction value of at least one L1 measurement result based on the L1 measurement prediction configuration information or logging at least one L1 measurement result value based on the L1 measurement logging configuration information; and transmitting a second message including the prediction value of at least one L1 measurement result or the logged at least one L1 measurement result value to the base station.

[0012] Additionally, the method may further include a step of transmitting to the base station a third message including at least one of information indicating whether the terminal supports L1 measurement prediction or information indicating whether the terminal supports L1 measurement logging.

[0013] Additionally, the L1 measurement prediction setting information may include at least one of cell information, beam information, prediction interval, prediction period, L1 filtering, L1 filtering parameter, or reporting period.

[0014] Additionally, the L1 measurement logging setting information may include at least one of cell information, beam information, logging interval, logging cycle, L1 filtering, L1 filtering parameter, or reporting cycle.

[0015] In addition, the method may further include a step of transmitting, to a target base station, a fourth message including information indicating that the predicted value of the at least one L1 measurement result or the logged at least one L1 measurement result value is stored in the terminal when a handover or cell reselection operation is performed; and a step of transmitting, to the target base station, a fifth message including the predicted value of the at least one L1 measurement result or the logged at least one L1 measurement result value based on a request of the target base station.

[0016] In addition, a method performed by a base station of a wireless communication system according to an embodiment of the present invention for solving the above-described problem may include the steps of transmitting a first message including L1 (layer 1) measurement prediction setting information or L1 measurement logging setting information to a terminal; and receiving a second message including a predicted value of at least one L1 measurement result generated based on the L1 measurement prediction setting information or at least one L1 measurement result value logged based on the L1 measurement logging setting information from the terminal.

[0017] Additionally, the method may further include a step of receiving a third message from the terminal, the third message including at least one of information indicating whether the terminal supports L1 measurement prediction or information indicating whether the terminal supports L1 measurement logging.

[0018] In addition, the method may further include: receiving, from the terminal, a fourth message including information indicating that a predicted value of the at least one L1 measurement result or the logged at least one L1 measurement result value is stored in the terminal when the base station is selected according to a cell reselection operation; transmitting, to the terminal, a fifth message including information requesting a predicted value of the at least one L1 measurement result or the logged at least one L1 measurement result value; and receiving, from the terminal, a sixth message including a predicted value of the at least one L1 measurement result or the logged at least one L1 measurement result value.

[0019] In addition, a terminal of a wireless communication system according to an embodiment of the present invention for solving the above-described problem may include a transceiver; and a control unit connected to the transceiver, configured to receive a first message including L1 (layer 1) measurement prediction setting information or L1 measurement logging setting information from a base station, generate a prediction value of at least one L1 measurement result based on the L1 measurement prediction setting information or log at least one L1 measurement result value based on the L1 measurement logging setting information, and transmit a second message including the prediction value of at least one L1 measurement result or the logged at least one L1 measurement result value to the base station.

[0020] In addition, a base station of a wireless communication system according to an embodiment of the present invention for solving the above-described problem may include a transceiver; and a control unit connected to the transceiver, transmitting a first message including L1 (layer 1) measurement prediction setting information or L1 measurement logging setting information to a terminal, and receiving a second message including a predicted value of at least one L1 measurement result generated based on the L1 measurement prediction setting information or at least one L1 measurement result value logged based on the L1 measurement logging setting information from the terminal.

[0021] According to one embodiment of the present disclosure, a method is provided, which is performed by a terminal and a base station of a wireless communication system or a mobile communication network equipment supporting artificial intelligence and machine learning (AL / ML). The method may include the steps of: receiving configuration information for channel state prediction of an AL / ML-based beam or cell, or measurement of a current beam or cell, from a base station; performing channel state prediction of an AL / ML-based beam or cell, or measurement of a current beam or cell, based on the configuration information; transmitting a report of the predicted or measured result to the base station based on the configuration information; terminating the measurement or prediction based on the configuration information from the base station or when a connection state is changed; and reporting the predicted or measured result upon a request from the base station.

[0022] According to various embodiments of the present disclosure, channel state prediction / measurement information of a beam or cell enabling a preemptive handover procedure can be started at a desired time, transmitted with low overhead, and prediction / measurement can be terminated according to the network situation, thereby increasing the overall performance and stability of the network without performance degradation due to prediction / measurement.

[0023] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0024] FIG. 1a is a diagram illustrating the structure of a mobile communication system according to one embodiment of the present disclosure.

[0025] FIG. 1b is a diagram for explaining a wireless connection state transition in a mobile communication system according to an embodiment of the present disclosure.

[0026] FIG. 1c is a flowchart for explaining a channel state measurement and handover process of a terminal according to an embodiment of the present disclosure.

[0027] FIG. 1da is a diagram showing a filtering structure of a terminal for explaining a Layer 1 measurement result and a Layer 3 measurement result according to an embodiment of the present disclosure.

[0028] FIG. 1db is a diagram illustrating an example of Layer 1 measurement report and Layer 3 measurement report operations according to one embodiment of the present disclosure.

[0029] FIG. 1e is a flowchart illustrating an AI / ML prediction report process of a terminal according to one embodiment of the present disclosure.

[0030] FIG. 1f is a flowchart illustrating a case in which a handover occurs during an AI / ML prediction report process of a terminal according to an embodiment of the present disclosure.

[0031] FIG. 1g is a flowchart illustrating a case in which a connection disconnection occurs during an AI / ML prediction report process of a terminal according to one embodiment of the present disclosure.

[0032] FIG. 1h is a flowchart illustrating a logging result report process for AI / ML of a terminal according to one embodiment of the present disclosure.

[0033] FIG. 1i is a flowchart illustrating a case in which a handover occurs during a logging result report process for AI / ML of a terminal according to an embodiment of the present disclosure.

[0034] FIG. 1j is a flowchart illustrating a case in which a connection disconnection occurs during a logging result report process for AI / ML of a terminal according to an embodiment of the present disclosure.

[0035] FIG. 1k is a diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0036] FIG. 1l is a diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0037] FIG. 1m is a diagram for explaining filter parameters that a base station can set together with whether or not to perform L1 filtering according to an embodiment of the present invention.

[0038] In describing the embodiments in this specification, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0039] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0040] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

[0041] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0042] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0043] Here, the term '~ unit' used in the present embodiment means a software or hardware component such as an FPGA or ASIC, and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to play one or more processors. Accordingly, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. Additionally, components and '~parts' may be implemented to regenerate one or more CPUs within a device or secure multimedia card.

[0044] FIG. 1a is a diagram illustrating the structure of a mobile communication system according to one embodiment of the present disclosure.

[0045] Referring to FIG. 1a, a wireless access network of a mobile communication system (New Radio, NR) according to an embodiment of the present disclosure may be composed of a base station (source next generation Node B, hereinafter referred to as source gNB) (1a-10) and an AMF (1a-05, access and mobility management function or New Radio Core Network). A user terminal (New Radio User Equipment, hereinafter referred to as (NR) UE or terminal) (1a-15) may access an external network (1a-20) through the source gNB (1a-10) and the AMF (1a-05). The terminal (1a-15) may measure a signal of an adjacent gNB (1a-30), which is an adjacent base station (1a-25). Here, the adjacent base station including the adjacent gNB (1a-30) may be a base station (eNB) of the NR system, a 3GPP series mobile communication system base station including an evolved node B (eNB) of an LTE system, or an AP of another mobile communication series. The mobile communication system according to one embodiment of the present disclosure may be a next-generation mobile communication system, and the base station may be a next-generation base station.

[0046] AMF (1a-05) can perform functions such as mobility support, bearer setup, and QoS (quality of service) setup. AMF (1a-05) is a device that is responsible for various control functions as well as mobility management functions for terminals (1a-15) and can be connected to multiple base stations.

[0047] In addition, the mobile communication v system according to one embodiment of the present disclosure can also be linked with an existing LTE system through connection with AMF (1a-05).

[0048] FIG. 1b is a diagram for explaining a wireless connection state transition in a mobile communication system according to an embodiment of the present disclosure.

[0049] Referring to FIG. 1b, a mobile communication system according to an embodiment of the present disclosure may have three radio connection states (RRC (radio resource control) states) or RRC modes. The connected mode (RRC_CONNECTED, 1b-05) is a radio connection state in which a terminal can transmit and receive data. The idle mode (RRC_IDLE, 1b-30) is a radio connection state in which a terminal monitors whether paging is transmitted to itself. The above two modes are radio connection states that are also applied to the existing LTE system, and the detailed technology is the same as that of the existing LTE system. The mobile communication system according to an embodiment of the present disclosure may be a next-generation mobile communication system.

[0050] In a mobile communication system according to an embodiment of the present disclosure, a new inactive (RRC_INACTIVE) radio connection state (1b-15) is defined. In this inactive radio connection state, the UE context is maintained between the base station and the terminal, and RAN (radio access network)-based paging can be supported. The characteristics of this inactive radio connection state are listed below.

[0051] - Cell re-selection mobility;

[0052] - CN - NR RAN connection (both C / U-planes (control plane / user plane)) has been established for UE;

[0053] - The UE AS (Access Stratum) context is stored in at least one gNB and the UE;

[0054] - Paging is initiated by NR RAN;

[0055] - RAN-based notification area is managed by NR RAN;

[0056] - NR RAN knows the RAN-based notification area which the UE belongs to;

[0057] - The connection between the terminal and the core network is maintained (CM CONNECTED state). Terminals in the CM connected state have NAS signaling connections through AMF and N1.

[0058] According to one embodiment of the present disclosure, a terminal in an inactive wireless connection state (1b-15) can transition to a connected mode (1b-05) or a standby mode (1b-30) using a specific procedure. The transition (1b-10) between the connected mode (1b-05) and the inactive mode (1b-15) can be performed through a Resume or a Release with suspend procedure. For example, the terminal can transition from the INACTIVE mode (1b-15) to the connected mode (1b-05) through a Resume procedure, and can transition from the connected mode (1b-05) to the INACTIVE mode (1b-15) by receiving a Release message including suspend configuration information (1b-10). The procedure is performed by transmitting and receiving one or more RRC messages between the terminal and the base station, and can consist of one or more steps. Additionally, the terminal can transition from INACTIVE mode (1b-15) to STANDBY mode (1b-30) (1b-20) through the Resume and Release procedures. The transition between connected mode (1b-05) and standby mode (1b-30) (1b-25) can follow existing LTE technology. For example, transitions between the above modes can be achieved through establishment or release procedures.

[0059] FIG. 1c is a flowchart illustrating a process in which a terminal performs cell measurement and reporting operations according to an embodiment of the present disclosure.

[0060] Referring to FIG. 1c, according to one embodiment of the present disclosure, in step 1c-15, the terminal (1c-05) may report its capability information (UE capability information, terminal capability information) to the base station (1c-10). In step 1c-20, the base station (1c-10) may transmit a message including configuration information (measConfig IE) related to cell measurement operation, for example, an RRCReconfiguration message (RRC reconfiguration message), to the terminal (1c-05).

[0061] The above configuration information (measConfig IE) may include information necessary for reporting the results measured by the terminal (1c-05) to the base station (1c-10) depending on the type of measurement report (e.g., periodical, event-triggered, event-triggered periodical). For example, in the case of "event-triggered" or "event-triggered periodical," the terminal (1c-05) may report a predetermined measurement result when a specific event set based on the configuration information is satisfied. For example, the following events may be set in the NR system.

[0062] - Event(s) related to typical intra- / inter-RAT measurements may be as shown in [Table 1] below.

[0063] Event A1: Serving becomes better than absolute threshold;Event A2: Serving becomes worse than absolute threshold;Event A3: Neighbour becomes amount of offset better than PCell / PSCell;Event A4: Neighbour becomes better than absolute threshold;Event A5: PCell / PSCell becomes worse than absolute threshold1 AND Neighbour / SCell becomes better than another absolute threshold2;Event A6: Neighbour becomes amount of offset better than SCell;Event D1: Distance between UE and a reference location referenceLocation1 becomes larger than configured threshold distanceThreshFromReference1 and distance between UE and a reference location referenceLocation2 becomes shorter than configured threshold distanceThreshFromReference2;Event B1: Neighbour becomes better than absolute threshold;Event B2: PCell becomes worse than absolute threshold1 AND Neighbour becomes better than another absolute threshold2;

[0064] - Similar to condition-based measurement reporting, in condition-based handover, when a specific event is met, the terminal (1c-05) can perform a handover based on condition-based handover configuration information. Event(s) related to condition-based handover may be as shown in [Table 2] below.

[0065] CondEvent A3: Conditional reconfiguration candidate becomes amount of offset better than PCell / PSCell;CondEvent A4: Conditional reconfiguration candidate becomes better than absolute threshold;CondEvent A5: PCell / PSCell becomes worse than absolute threshold1 AND Conditional reconfiguration candidate becomes better than another absolute threshold2;CondEvent D1: Distance between UE and a reference location referenceLocation1 becomes larger than configured threshold distanceThreshFromReference1 and distance between UE and a reference location referenceLocation2 of conditional reconfiguration candidate becomes shorter than configured threshold distanceThreshFromReference2;CondEvent T1: Time measured at UE becomes more than configured threshold t1-Threshold but is less than t1-Threshold + duration;

[0066] - (Sidelink) When a specific event is satisfied in the Relay, the terminal (1c-05) can perform a specific action. Event(s) related to the Relay may be as shown in [Table 3] below.

[0067] Event X1: Serving L2 U2N Relay UE becomes worse than absolute threshold1 AND NR Cell becomes better than another absolute threshold2;Event

[0068] - In the case of NR-U (Unlicensed), when a specific event is satisfied, the terminal (1c-05) can perform a specific action. Event(s) related to NR-U may be as shown in [Table 4] below.

[0069] Event I1: Interference becomes higher than absolute threshold.

[0070] In step 1c-25, terminal (1c-05) can evaluate whether the configured Events are satisfied. If the Events described above continue to satisfy a predetermined condition for a predetermined time interval (time-to-trigger), terminal (1c-05) can consider (judge, identify) that the Event is satisfied.

[0071] In step 1c-30, when the set condition is satisfied, the terminal (1c-05) may report a MeasurementReport message (measurement report message) containing the measurement result to the base station (1c-10). Alternatively, although not shown, depending on the embodiment, the terminal (1c-05) may perform a predetermined operation corresponding to the above condition, for example, a condition-based handover (HO).

[0072] The base station (1c-10) that receives the above measurement results can use the measurement results for a predetermined purpose. For example, in step 1c-35, the base station (1c-10) can determine whether to trigger a handover of the terminal (1c-05). If the base station (1c-10) triggers a handover, in step 1c-40, the base station (1c-10) can request the handover to the target cell(s) (HO coordination with the target(s)). In step 1c-45, the base station (1c-10) can transmit handover configuration information configured based on predetermined configuration information received from the target cell(s) to the terminal (1c-05). In step 1c-50, the terminal (1c-05) that received the configuration information can execute the handover.

[0073] FIG. 1da and FIG. 1db are drawings for explaining an operation of reporting a measurement result when a specific condition is satisfied according to one embodiment of the present disclosure.

[0074] Referring to Figure 1dA, a terminal may undergo a filtering process to report a channel condition that changes in real time to a base station. When a terminal receives K beams transmitted from a base station, the terminal may perform Layer 1 filtering (1d-a-10) on its own physical layer and transmit it to Layer 3. At this time, the terminal may report the Layer 1 filtered value to the base station in the form of a CSI report, which is hereinafter referred to as an L1 measurement result for convenience.

[0075] The channel status of each Layer1 filtered beam selects the number of beams for calculation according to the configured value to produce a cell-level measurement result (beam selection), and then through the Layer3 filtering (1d-a-15) process, a single cell-level measurement result can be derived (layer 3 filtering for cell quality). For convenience, this is referred to as the L3 measurement result below.

[0076] Cell-level L3 measurement evaluates whether the conditions of the event set in [Table 1] to [Table 4] are satisfied (evaluating reporting criteria), and if the conditions of the event are satisfied, the terminal generates a measurement report (1d-a-20) and transmits it to the base station. In addition, in the case of the L3 measurement result, even if the base station configures cell-level information, the terminal can report it as a beam-level measurement result, and for this purpose, Layer 3 filtering can be performed on a beam-level basis. The L3 measurement result performed on a beam-level basis can be selected for reporting (beam selection for reporting) (1d-a-25).

[0077] Referring to FIG. 1db, the terminal (1d-10) can evaluate the signal strength or quality of the base station (1d-05) signal based on the SSB (synchronization signal block or SS / PBCH block) or CSI-RS (channel state information reference signal) transmitted from the base station (1d-05). Hereinafter, for convenience of explanation, the measurement result reporting operation of the terminal (1d-10) is described mainly with respect to SSB, but the same can be applied to CSI-RS.

[0078] In the case of SSB, the transmission cycle of SSB can be determined according to the settings of the base station (1d-05). Typically, the transmission cycle of SSB can be set to 20 ms, and the base station (1d-05) can transmit SSB with a cycle of up to 160 ms.

[0079] When the base station (1d-05) sets Event A2 to the terminal (1d-10), the terminal (1d-10) can continuously evaluate whether the RSRP value measured based on SSB is lower than the threshold during a predetermined time period (time-to-trigger, TTT, trigger time) from the time point (T1) (1d-15) when the RSRP (reference signal received power) value measured based on SSB becomes lower than the set absolute threshold value. At this time, the measured value can be set as an indicator of channel quality, such as RSRQ (reference signal received quality) or SINR (signal to interference ratio), in addition to RSRP. In the conventional case, the measured RSRP, RSRQ, or SINR value is an L3 measurement result value.

[0080] If the RSRP value measured based on SSB is continuously lower than the threshold from the initial time point (T1) (1d-15) when the RSRP value is lower than the set absolute threshold value to the time point (T2) (1d-20) when the time interval has elapsed, the terminal (1d-10) may consider that the Event A2 is satisfied and may report a measurement report triggered by the Event A2 to the base station (1d-05). As described above, by considering the TTT in determining whether the conditions for performing the measurement report are satisfied, the variability of the measurement signal may be corrected. The TTT value may be set by the base station (1d-05) for each Event.

[0081] If the above-mentioned Events continuously satisfy a predetermined condition for a predetermined time interval (TTT), the terminal (1d-10) can perform an operation corresponding to the purpose of the set Event. If the type of measurement report according to the measurement-related setting information received by the terminal (1d-10) is set to "periodical" or "event-triggered periodical," the terminal (1d-10) can perform a measurement report periodically.

[0082] When the base station (1d-05) configures the terminal (1d-10), the terminal can report the RSRP value measured once (aperiodic), periodically (periodic), or continuously (semi-persistency) after receiving a start command. For example, if the base station (1d-05) configures the semi-persistency report to the terminal (1d-10) and then issues a start command at time T'1, the terminal (1d-10) can report the RSRP value at that time until time T'4 according to the configured CSI report cycle and section. At this time, the value reported by the terminal (1d-10) can be RSRP or SINR, and in the conventional case, this value is the L1 measurement result.

[0083] Even if you use the conventional handover method up to Rel-18, including CHO (Conditional handover = conditional handover), CPAC (Conditional PSCell Addition or Change), CPA (Conditional PSCell Addition), CPC (Conditional PSCell Change), LTM (lower-layer triggered mobility), etc., you can improve the performance by using artificial intelligence and machine learning (AI / ML), and for this purpose, you can utilize the future measurement results predicted by AI / ML at the terminal. In addition, in the case of the AI / ML-based preemptive handover method that is expected to appear after Rel-19, the past measurement results of the terminal may be required to perform AI / ML at the base station.

[0084] To support the high-density cell deployment and high mobility expected in next-generation mobile communication systems, measurement results may require conventional L3 and L1 measurements, or even unfiltered results. These results are expected to be a series of results rather than a single value. This can lead to issues such as high overhead and resource constraints in reporting these measurements.

[0085] When following the conventional reporting method, the L1 measurement result report based on Rel-18 can be reported using the UCI (Uplink control indicator) of Layer 2 or the Measurement report of the RRC layer. When reporting using UCI, the base station can set reportConfigID, target PCI, beam idx, and report type in csi-reportConfigToAddModList via the RRCReconfiguration message, thereby allowing the terminal to include the L1 measurement report for a specific base station and beam pair in the CSI report of the UCI (Uplink Control Information).

[0086] This method can be configured with a report type of aperiodic method that reports once using DCI (Downlink Control Information), semi-persistency method that starts reporting using DCI and reports for a specified period, and periodic method that continuously reports for the targets set in csi-reportConfigToAddModList without DCI. These methods cannot currently report RSRQ, and due to limitations in the number of base stations and beams, an increase in the number of UCI bits may inevitably be required for multiple measurement reports. Furthermore, if the number of UCI bits is not increased, the number of transmissions must be increased, which may inevitably lead to an increase in PUCCH / PUSCH resources.

[0087] When transmitting beam measurement reports via RRC, Rel-18 standards do not allow the target beam index to be added, nor can serialized results be included in the message. In this case, a method is essential to reduce overhead by precisely specifying the target beam, allowing the terminal to locate it, and including the serialized results in the measurement report.

[0088] In addition, even if serial results are included, in order to prevent the number of reports from affecting the performance of the existing network, a method is needed to separate the prediction / measurement cycle and the reporting cycle, start measurement and reporting at the desired time, report serially, and terminate prediction / measurement when it is determined that sufficient training data has been received or when a problem occurs with the current RRC connection.

[0089] Although the embodiments of the present invention have been described with handover to aid understanding, they can be applied to any situation where prediction / measurement for AI / ML is required depending on the settings of the base station and the capabilities of the terminal while the terminal is in a network.

[0090] FIG. 1e is a flowchart illustrating a prediction result reporting process (hereinafter, UE side AI / ML model) according to one embodiment of the present disclosure.

[0091] Referring to FIG. 1e, in step 1e-05, a connected mode terminal (UE) may transmit to a base station (source gNB) a terminal capability information message (e.g., a UE capability information message) that includes information indicating that the terminal is a terminal capable of AI / ML or measurement prediction or information indicating whether the terminal is a terminal capable of AI / ML or measurement prediction. The UE capability information message may be a message transmitted by the terminal in response to a UE capability enquiry message previously received from the base station.

[0092] In step 1e-10, the base station can transmit measurement configuration information to the terminal. This process is an example of a measurement configuration for instructing prediction, and any event can be used, including a conventional event, a periodic report, or an event predicted by AI / ML. The measurement configuration information (measConfig) can be transmitted in an RRC reconfiguration message.

[0093] In step 1e-15, the terminal can report the measurement results to the base station according to the measurement-related settings received from the base station (measurement report). Similar to step 1e-10, this step is only an example of a trigger point for starting step 1e-20, and it can be omitted depending on the base station implementation, such as a base station that has only received UE capability information going directly to step 1e-20 regardless of whether the base station has received the corresponding MR (measurement report), or triggering can also be done based on low layer input.

[0094] In step 1e-20, the base station can instruct (set up, configure) the terminal to perform L1 measurement prediction. At this time, the base station can configure the cell to be measured, beam ID, prediction interval, prediction period, report type, L1 filtering, L1 filtering parameter, report interval, etc. to the terminal. At this time, the method for instructing the prediction can use at least one of the following methods: a method of creating a completely new MeasID by setting a new type of MeasObject (such as MeasObjectAIML) and reportConfigID; a method of adding an IE such as PredictionAllowed and configuration information belonging to PredictionAllowed to an existing reportConfigID to check and add Prediction to the same MeasID; a method of adding a PredictionAllowed IE to an RRCReconfiguration message so that a measurement report including PredictionAllowed for the corresponding MeasID includes a prediction result; a method of allowing events belonging to measurement reports corresponding to all MeasIDs in the corresponding message to include a prediction result.

[0095] FIG. 1m is a diagram for explaining filter parameters that a base station can set together with whether or not to perform L1 filtering according to an embodiment of the present invention.

[0096] Referring to Fig. 1m, each L1 sample is a channel state value measured by the lower L1 of the terminal, and may be a value measured for a target designated by the base station, such as SSB or CSI-RS. The minimum possible period of the L1 sample may be the period of the measurement target. First, the base station can designate the filtering method as a sliding method, a non-sliding method, or a third method. In the case of the sliding method shown in (a) of Fig. 1m, the sliding length can be set, and the example shown in (a) of Fig. 1m means a sliding length of 1. In the case of the non-sliding method shown in (b) of Fig. 1m, it operates in the same way as when the sliding length is equal to the filtering length, and this can be distinguished and designated as a non-sliding method or designated using the sliding length. In addition, the base station can set the number of L1 samples to be collected and made into L1 filtered RSRP within the measurement period by setting the filter length. The unit can be set as time unit, number unit, or multiple of L1 sample unit. In the example of Fig. 1m, the filter length is 4. In addition, it is possible to specify whether to give the weight of each sample the same value or designate the weight as a different value. For example, the filter coefficient can be designated in the same form as Layer 3 filtering of TS38.331 section 5.5.3.2. In this case, the measurement period can be set to a value that does not exceed the measurement period of the requirement defined in TS38.133 or can be newly defined and set.The base station can also configure whether to use L3 filtering when L1 filtering is configured. In addition, the L1 filtering configuration value can be configured for the base station to change or delete via an RRC message.

[0097] Looking at FIG. 1m in more detail, in the sliding method of (a) of FIG. 1m, the sliding length is 1, and the filter length is 4, as exemplified. In this case, the 4th L1 filtered RSRP value can be generated by filtering the 1st, 2nd, 3rd, and 4th values ​​of the L1 samples. In addition, the 5th L1 filtered RSRP value can be generated by filtering the 2nd, 3rd, 4th, and 5th values ​​of the L1 samples, and the 6th L1 filtered RSRP value can be generated by filtering the 3rd, 4th, 5th, and 6th values ​​of the L1 samples. In this way, the L1 filtered RSRP value can be generated by sliding the L1 samples one by one. Depending on the embodiment, the 1st L1 filtered RSRP value may be generated by filtering only the 1st value of the L1 samples, or may be generated by using the 1st value of the L1 samples and the three previous L1 sample values ​​(not shown).

[0098] In the non-sliding method of (b) of Fig. 1m, the sliding length is 1 and the filter length is 4, as exemplified. In this case, the 1st L1 filtered RSRP value can be generated by filtering the 1st, 2nd, 3rd, and 4th values ​​among the L1 samples. In addition, the 2nd L1 filtered RSRP value can be generated by filtering the 5th, 6th, 7th, and 8th values ​​among the L1 samples. In this way, the L1 samples used to generate the previous L1 filtered RSRP value can be omitted when generating the L1 filtered RSRP value.

[0099] Referring back to FIG. 1e, the base station can request UEAssistanceInformation from the terminal using OtherConfig in the RRCReconfiguration message, and at this time, the terminal can transmit the L1 filtering configuration value in the UEAssistanceInformation to the base station. This process can be omitted or not requested if the base station transmits the L1 filtering configuration value via the RRCReconfiguration message.

[0100] In step 1e-25, the terminal can generate a predicted value at each prediction interval set by the base station. For example, if the prediction interval is 1 second and the prediction periodicity is 10 seconds for a target cell with cell ID 1 and beam ID 1, the terminal can predict the RSRP predicted value in 1-second units up to 10 seconds later. In this case, the predicted value may be the L1 filtered RSRP value illustrated in FIG. 1m.

[0101] In step 1e-30, the terminal can transmit all values ​​within the prediction periodic to the base station in a single MR (measurement report). At this time, the terminal can indicate a new MeasID or an existing MeasID and the predictionAllowed IE together. The measurement report indicates a serial value corresponding to each cell and beam index, and this value can be an absolute index or a differential index. The MR transmitted in step 1e-30 can use a conventional SRB (Signal Radio Bearer) (e.g., SRB1,3), but can also define and use a new bearer such as SRB4 according to the bearer policy of Rel-19.

[0102] In this Figure 1e, the case where the report is MR is considered, but the reserved index in [Table 5] below, or the available LCID when the LCID increases after Rel-19, can be used to transmit it to MAC CE and UL-SCH. For example, in the case of index 38, it can be indicated as an L1 measurement report and its priority can be lowered compared to other indexes to be processed later.

[0103] Table 6.2.1-2: Values of LCID for UL-SCH when the LX field is not present or is set to 0Codepoint / IndexLCID values0CCCH of size 64 bits, except for an (e)RedCap UE1-32Identity of the logical channel of DCCH and DTCH33Extended logical channel ID field (two-octet eLCID field)34Extended logical channel ID field (one-octet eLCID field)35CCCH of size 48 bits for a RedCap UE36CCCH of size 64 bits for a RedCap UE37SL LBT failure38-42Reserved43Truncated Enhanced BFR (one octet C i )44Timing Advance Report45Truncated Sidelink BSR46Sidelink BSR47Reserved48LBT failure (four octets)49LBT failure (one octet)50BFR (one octet C i )51Truncated BFR (one octet C i )52CCCH of size 48 bits, except for an (e)RedCap UE53Recommended bit rate query54Multiple Entry PHR (four octets C i )55Configured Grant Confirmation56Multiple Entry PHR (one octet C i)57Single Entry PHR58C-RNTI59Short Truncated BSR60Long Truncated BSR61Short BSR62Long BSR63PaddingNOTE: CCCH of size 48 bits and CCCH of size 64 bits are referred to as CCCH and CCCH1, respectively, in TS 38.331 [5].

[0104] In step 1e-35, the base station may transmit an RRCReconfiguration message to the terminal, which includes an information element (IE) that terminates measurement prediction. At this time, the base station may release a specific MeasID through an IE such as the existing CellToremoveList, transmit a PredictionRelease IE to the terminal to terminate all predictions for the terminal, or transmit PredictionRelease and MeasID together to the terminal to terminate predictions for only the corresponding MeasID.

[0105] FIG. 1f is a flowchart illustrating a case in which a handover occurs during a prediction report according to an embodiment of the present disclosure.

[0106] Referring to FIG. 1f, steps 1f-05 to 1f-30 are similar to steps 1e-05 to 1e-30 described in FIG. 1e, and thus, a detailed description thereof will be omitted.

[0107] When a handover occurs in step 1f-35 and the RRC connection of the terminal is moved to another base station (target base station), the terminal can immediately terminate the prediction it was performing without receiving another message from the existing base station (source base station) or the target base station.

[0108] As an example of step 1f-35, the source gNB may include the prediction result of the terminal received before the handover in the UE context message included when transmitting the handover request message to the target gNB before the handover occurs.

[0109] When the terminal transmits an RRCReconfigurationComplete message (RRC reconfiguration complete message) for the handover command to the target base station in step 1f-40, the terminal can transmit information indicating that there is a prediction result performed so far, for example, a 1-bit IE to the target base station (e.g., RemainPrediction IE, etc.). At this time, a boolean can be used, where the value of the IE is 1 if there is a prediction result stored in the terminal, and the value of the IE is 0 if there has been no prediction.

[0110] In step 1f-45, the target gNB may request the UE to transmit the remaining prediction results it has by sending a UE Information request message. At this time, the UE may transmit the remaining prediction results through a UE Information Response message. For this purpose, a new UEPredictionResult IE may be defined within the UE Information Response, and the IE may contain a Measurement report or have an IE format similar to the Measurement report. At this time, the target gNB may transmit the UE Information request message to the UE depending on the base station implementation, and this step may be omitted.

[0111] FIG. 1g is a flowchart illustrating a case in which a connection break occurs according to an embodiment of the present disclosure.

[0112] Referring to FIG. 1g, steps 1g-05 to 1g-30 are similar to steps 1e-05 to 1e-30 described in FIG. 1e, so a detailed description thereof will be omitted.

[0113] If a radio link failure (RLF) occurs after step 1g-30 due to RLC max re-transmission or RLF (radio link failure) timer expiration, the UE may immediately terminate the prediction operation in step 1g-35. At this time, the UE may perform RRC re-establishment with the existing source gNB or a new gNB according to the cell reselection procedure.

[0114] If the source cell is selected as a result of cell reselection of the UE, the UE can perform an RRC Re-establishment request to the source gNB in ​​step 1g-40a. At this time, the source gNB transmits an RRC Re-establishment accept to the UE, and the UE can transmit information notifying that there is a prediction result performed so far in the RRC Re-establishment complete message, for example, a 1-bit IE (e.g., RemainPrediction IE). At this time, a boolean can be used, where the value of the corresponding IE is 1 if there is a prediction result stored in the UE, and the value of the corresponding IE is 0 if there has been no prediction. Even if the UE receives an RRC Release in addition to an RLF and performs the setup procedure, the UE can include the RemainPrediction IE in the RRCSetupComplete message.

[0115] If a different cell is selected as a result of cell reselection of the terminal, the terminal can transmit an RRC Re-establishment request to the gNB (target base station) in step 1g-40b. At this time, if the base station receives the message, the terminal can transmit information indicating that there is a prediction result performed so far, for example, a 1-bit IE, in the RRC Re-establishment complete message. At this time, a boolean can be used, where the value of the IE is 1 if there is a prediction result stored in the terminal, and the value of the IE is 0 if there has been no prediction.

[0116] In some embodiments, when the target gNB transmits an RRCSetup message in response to an RRC Re-esatablishment request and moves to the setup procedure, the terminal may transmit an IE of 1 bit size together with the RRCSetupComplete message.

[0117] In step 1g-45a, the gNB may request the UE to transmit the remaining prediction results it has by sending a UE Information request message. At this time, the UE may transmit the remaining prediction results to the base station via a UE Information Response message. For this purpose, a new UEPredictionResult IE may be defined within the UE Information Response, and the IE may contain a Measurement report or have an IE format similar to the Measurement report. At this time, the transmission of the UE Information request message by the gNB to the UE may vary depending on the base station implementation, and this step may be omitted.

[0118] In steps 1g-45b, the target gNB may request the UE to transmit the remaining prediction results it has by sending a UE Information request message. At this time, the UE may transmit the remaining prediction results via a UE Information Response message. To this end, a new UEPredictionResult IE may be defined within the UE Information Response, and this IE may contain a Measurement report or have an IE format similar to the Measurement report. At this time, the target gNB may transmit the UE Information request message to the UE depending on the base station implementation, and this step may be omitted.

[0119] As an example of step 1g-45b, when the target gNB performs the setup procedure, the target gNB can identify the gNB where the RLF occurred through the RLF report. The target gNB transmits a RETRIEVE UE CONTEXT message to the existing source gNB to initiate the setup procedure, and when the source gNB transmits a RETRIVE UE CONTEXT RESPONSE message to the target gNB, the prediction result can be transmitted to the target gNB together.

[0120] FIG. 1h is a flowchart illustrating a logging result report process for AI / ML of a terminal according to one embodiment of the present disclosure.

[0121] Figure 1h is a flowchart of a case where AI / ML is performed at a base station or network equipment (AMF, OTT, etc.) connected to a base station.

[0122] The configuration of steps 1h-05 to 1h-35 is similar to steps 1e-05 to 1e-30 described in FIG. 1e. However, in the embodiment exemplarily described in FIG. 1h, prediction in the operations and settings performed by the terminal may be replaced with logging.

[0123] Referring to FIG. 1h, in step 1h-05, a connected mode terminal may transmit to a base station a terminal capability information message (e.g., a UE capability information message) that includes information indicating that the terminal is a terminal capable of AI / ML or measurement prediction or information indicating whether the terminal is a terminal capable of AI / ML or measurement prediction. The UE capability information message may be a message transmitted by the terminal in response to a UE capability enquiry message previously received from the base station.

[0124] In steps 1h-10, the base station can transmit measurement settings to the terminal. This process is an example of a measurement configuration for instructing logging, and any event can be used, including a conventional event, a periodic report, or an event predicted by AI / ML. The measurement configuration information (measConfig) can be transmitted in an RRC reconfiguration message.

[0125] In step 1h-15, the terminal can report the measurement results to the base station according to the measurement-related settings received from the base station (measurement report). Similar to step 1h-10, this step is only an example of a trigger point for starting step 1h-20, and it can be omitted depending on the implementation of the base station, such as a base station that has only received UE capability information and proceeds directly to step 1h-20 regardless of whether the base station has received the corresponding MR (measurement report), or triggering can also be done based on low layer input.

[0126] In step 1h-20, the base station can instruct (set up, configure) L1 measurement logging to the terminal. At this time, the base station can configure the cell to be measured, beam ID, logging interval, logging period, report type, L1 filtering, L1 filtering parameter, report interval, etc. to the terminal. At this time, the method for instructing logging can use at least one of the following methods: a method of creating a completely new MeasID by setting a new type of MeasObject (such as MeasObjectAIML) and reportConfigID; a method of checking and adding whether to log to the same MeasID by adding an IE such as LoggingAllowed and configuration information belonging to LoggingAllowed to an existing reportConfigID; a method of adding a LoggingAllowed IE to an RRCReconfiguration message so that a measurement report including LoggingAllowed for the corresponding MeasID includes the logging result; a method of allowing events belonging to Measurement reports corresponding to all MeasIDs in the corresponding message to include the logging result.

[0127] The base station can request UEAssistanceInformation from the terminal using OtherConfig in the RRCReconfiguration message, and at this time, the terminal can transmit the L1 filtering setting value in the UEAssistanceInformation to the base station.

[0128] A diagram illustrating the filter parameters that can be set by the base station along with whether L1 filtering is performed is shown in Fig. 1m. Referring to Fig. 1m, each L1 sample is a channel state value measured by the lower L1 of the terminal, which may be a value measuring a target designated by the base station, such as SSB or CSI-RS. The minimum possible period of the L1 sample may be the period of the measurement target. First, the base station can designate the filtering method as a sliding method, a non-sliding method, or a third method. In the case of the sliding method shown in (a) of Fig. 1m, the sliding length can be set, and the example shown in (a) of Fig. 1m means a sliding length of 1. In the case of the non-sliding method shown in (b) of Fig. 1m, it operates in the same way as when the sliding length is equal to the filtering length, and this can be distinguished and designated as a non-sliding method or designated using the sliding length. In addition, the base station can set the number of L1 samples to be collected and made into L1 filtered RSRP within the measurement period by setting the filter length. The unit can be set as time unit, number unit, or multiple of L1 sample unit. In the example of Fig. 1m, the filter length is 4. In addition, it can be specified whether to give the weight of each sample the same value or designate the weight as different values. For example, the filter coefficient can be specified in the same form as Layer 3 filtering of TS38.331 section 5.5.3.2. In this case, the measurement period is TS38.The measurement period defined in the requirement in 133 can be used as is, or a new value that does not exceed the period can be defined and set. The base station can also configure whether to use L3 filtering when L1 filtering is configured. In addition, the L1 filtering setting value can be configured so that the base station changes or deletes it via an RRC message. In this case, the values ​​logged by the terminal may be L1 sample values.

[0129] Referring back to Figure 1h, this process can be set to be omitted or not requested if the base station sends the L1 filtering setting value through the RRCReconfiguration message.

[0130] In step 1h-25, the terminal can generate a prediction value (log the L1 measurement result) at each logging interval set by the base station. For example, if the logging interval is 1 second and the logging periodic is 10 seconds for a target cell with cell ID 1 and beam ID 1, the terminal can predict (log) the RSRP prediction value for up to 10 seconds in 1-second units.

[0131] In step 1h-30, the terminal can transmit all values ​​within the logging periodic to the base station in a single MR. At this time, the terminal can indicate a new MeasID or an existing MeasID and the LoggingAllowed IE together. The measurement report indicates a serial value corresponding to each cell and beam index, and this value can be an absolute index or a differential index. The MR transmitted in step 1h-30 can use a conventional SRB (Signal Radio Bearer) (e.g., SRB1,3), but a new bearer such as SRB4 can also be defined and used according to the bearer policy of Rel-19.

[0132] In this Figure 1h, the case where the report is MR is considered, but the reserved index in [Table 5] above, or the LCID that is available when the LCID increases after Rel-19, can be used to transmit to MAC CE and UL-SCH. For example, in the case of index 38, it can be indicated as an L1 measurement report and its priority can be lowered compared to other indexes to be processed later.

[0133] Although not shown, the base station can predict the L1 measurement result using the logged L1 measurement result values ​​received from the terminal.

[0134] Referring to FIG. 1m, in the sliding method of (a) of FIG. 1m, the sliding length is 1 and the filter length is 4, as an example. In this case, the base station can generate the 4th L1 filtered RSRP value by filtering the 1st, 2nd, 3rd, and 4th values ​​of the L1 samples. In addition, the 5th L1 filtered RSRP value can be generated by filtering the 2nd, 3rd, 4th, and 5th values ​​of the L1 samples, and the 6th L1 filtered RSRP value can be generated by filtering the 3rd, 4th, 5th, and 6th values ​​of the L1 samples. In this way, the base station can generate the L1 filtered RSRP value by sliding the L1 samples one by one. Depending on the embodiment, the 1st L1 filtered RSRP value may be generated by filtering only the 1st value of the L1 samples, or may be generated by using the 1st value of the L1 samples and the three previous L1 sample values ​​(not shown).

[0135] And, in the non-sliding method of (b) of FIG. 1m, the sliding length is 1 and the filter length is 4, as exemplified. In this case, the base station can generate the first L1 filtered RSRP value by filtering the 1st, 2nd, 3rd, and 4th values ​​among the L1 samples. And, the second L1 filtered RSRP value can be generated by filtering the 5th, 6th, 7th, and 8th values ​​among the L1 samples. In this way, the L1 sample used to generate the previous L1 filtered RSRP value can be omitted when generating the L1 filtered RSRP value.

[0136] In this way, the base station can predict the L1 filtered RSRP value.

[0137] In step 1h-35, the base station may transmit an RRCReconfiguration message to the terminal, which includes an information element (IE) that terminates measurement prediction (logging). At this time, the base station may release a specific MeasID through an IE such as the existing CellToremoveList, transmit a LoggingRelease IE to the terminal to terminate all logging of the terminal, or transmit LoggingRelease and MeasID together to the terminal to terminate logging of only the corresponding MeasID.

[0138] FIG. 1i is a flowchart illustrating a case in which a handover occurs during a logging result report process for AI / ML of a terminal according to an embodiment of the present disclosure.

[0139] Referring to FIG. 1i, steps 1i-05 to 1i-30 are similar to steps 1h-05 to 1h-30 described in FIG. 1h, and thus a detailed description thereof will be omitted.

[0140] When a handover occurs in step 1i-35 and the RRC connection of the terminal is moved to another base station (target base station), the terminal can immediately stop the logging being performed without receiving another message from the existing base station (source base station) or the target base station.

[0141] As an example of step 1i-35, the source gNB may include the logging result of the terminal received before the handover in the UE context message included when transmitting the handover request message to the target gNB before the handover occurs.

[0142] When the terminal transmits the RRCReconfigurationComplete message for the handover command to the target base station in step 1i-40, the terminal can transmit information indicating that there is a logging result performed so far, for example, a 1-bit IE to the target base station (e.g., RemainLogging IE). At this time, a boolean can be used that sets the value of the corresponding IE to 1 if there is a logging result stored in the terminal, and to 0 if there has been no logging.

[0143] In step 1i-45, the target gNB may request the UE to transmit the remaining logging results it has by sending a UE Information request message. At this time, the UE may transmit the remaining logging results via a UE Information Response message. To this end, a new UELoggingResult IE may be defined within the UE Information Response, and the IE may contain a Measurement report or have an IE format similar to the Measurement report. At this time, the target gNB may transmit the UE Information request message to the UE depending on the base station implementation, and this step may be omitted.

[0144] FIG. 1j is a flowchart illustrating a case in which a connection disconnection occurs during a logging result report process for AI / ML of a terminal according to an embodiment of the present disclosure.

[0145] Referring to FIG. 1j, steps 1j-05 to 1j-30 are similar to steps 1h-05 to 1h-30 described in FIG. 1h, and thus a detailed description thereof will be omitted.

[0146] If a radio link failure (RLF) occurs after step 1j-30 due to RLC max re-transmission or RLF timer expiration, the UE may immediately terminate logging operation in step 1j-35. At this time, the UE may perform RRC re-establishment with the existing source gNB or a new gNB according to the cell reselection procedure.

[0147] If the source cell is selected as a result of cell reselection of the UE, the UE can perform an RRC Re-establishment request to the source gNB in ​​step 1j-40a. At this time, the source gNB transmits an RRC Re-establishment accept to the UE, and the UE can transmit information notifying that there is a logging result performed so far in the RRC Re-establishment complete message, for example, a 1-bit IE (e.g., RemainLogging IE). At this time, a boolean that sets the value of the corresponding IE to 1 if there is a logging result stored in the UE, and to 0 if there has been no logging can be used. Even if the UE receives an RRC Release in addition to an RLF and performs the setup procedure, the UE can include the RemainLogging IE in the RRCSetupComplete message.

[0148] If a different cell is selected as a result of cell reselection of the terminal, the terminal can transmit an RRC Re-establishment request to the gNB (target base station) in step 1j-40b. At this time, if the base station receives the message, the terminal can transmit information notifying that there is a logging result performed so far, for example, a 1-bit IE, in the RRC Re-establishment complete message. At this time, a boolean can be used that sets the value of the IE to 1 if there is a logging result stored in the terminal, and sets the value of the IE to 0 if there has been no logging.

[0149] In some embodiments, when the target gNB transmits an RRCSetup message in response to an RRC Re-esatablishment request and moves to the setup procedure, the terminal may transmit an IE of 1 bit size together with the RRCSetupComplete message.

[0150] In step 1j-45a, the gNB may request the UE to transmit the remaining logging results held by the UE by sending a UE Information request message. At this time, the UE may transmit the remaining logging results to the base station via a UE Information Response message. For this purpose, a new UELoggingResult IE may be defined within the UE Information Response, and the IE may contain a Measurement report or have an IE format similar to the Measurement report. At this time, the transmission of the UE Information request message by the gNB to the UE may vary depending on the base station implementation, and this step may be omitted.

[0151] In steps 1j-45b, the target gNB may request the UE to transmit the remaining logging results it has by sending a UE Information request message. At this time, the UE may transmit the remaining logging results via a UE Information Response message. For this purpose, a new UELoggingResult IE may be defined within the UE Information Response, and the IE may contain a Measurement report or have an IE format similar to the Measurement report. At this time, the target gNB may transmit the UE Information request message to the UE depending on the base station implementation, and this step may be omitted.

[0152] As an example of step 1j-45b, when the target gNB performs the setup procedure, the target gNB can identify the gNB where the RLF occurred through the RLF report. The target gNB transmits a RETRIEVE UE CONTEXT message to the existing source gNB to initiate the setup procedure, and when the source gNB transmits a RETRIVE UE CONTEXT RESPONSE message to the target gNB, the logging result can be transmitted to the target gNB together.

[0153] FIG. 1k is a diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

[0154] Referring to FIG. 1k, the terminal includes an RF (Radio Frequency) processing unit (1k-10), a baseband processing unit (1k-20), a storage unit (1k-30), and a control unit (1k-40).

[0155] The RF processing unit (1k-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1k-10) up-converts the baseband signal provided from the baseband processing unit (1k-20) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1k-10) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. In the drawing, only one antenna is illustrated, but the terminal may be equipped with multiple antennas. In addition, the RF processing unit (1k-10) may include multiple RF chains. Furthermore, the RF processing unit (1k-10) may perform beamforming. For the above beamforming, the RF processing unit (1k-10) can adjust the phase and size of each signal transmitted and received through multiple antennas or antenna elements. In addition, the RF processing unit can perform MIMO and receive multiple layers when performing the MIMO operation.

[0156] The baseband processing unit (1k-20) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the baseband processing unit (1k-20) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (1k-20) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (1k-10). For example, in the case of following the OFDM (orthogonal frequency division multiplexing) method, when transmitting data, the baseband processing unit (1k-20) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by performing an inverse fast Fourier transform (IFFT) operation and inserting a cyclic prefix (CP). In addition, when receiving data, the baseband processing unit (1k-20) divides the baseband signal provided from the RF processing unit (1k-10) into OFDM symbol units, restores signals mapped to subcarriers through FFT (fast Fourier transform) operation, and then restores the received bit string through demodulation and decoding.

[0157] The baseband processing unit (1k-20) and the RF processing unit (1k-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (1k-20) and the RF processing unit (1k-10) may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. Furthermore, at least one of the baseband processing unit (1k-20) and the RF processing unit (1k-10) may include a plurality of communication modules to support a plurality of different wireless access technologies. In addition, at least one of the baseband processing unit (1k-20) and the RF processing unit (1k-10) may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include a wireless LAN (e.g., IEEE 802.11), a cellular network (e.g., LTE), etc. Additionally, the different frequency bands may include a super high frequency (SHF) (e.g., 2.NRHz, NRhz) band and a millimeter wave (mm wave) (e.g., 60GHz) band.

[0158] The above storage unit (1k-30) stores data such as basic programs, application programs, and setting information for the operation of the terminal. The above storage unit (1k-30) provides the stored data upon request from the control unit (1k-40).

[0159] The control unit (1k-40) controls the overall operations of the terminal. For example, the control unit (1k-40) transmits and receives signals through the baseband processing unit (1k-20) and the RF processing unit (1k-10). In addition, the control unit (1k-40) records and reads data in the storage unit (1k-30). For this purpose, the control unit (1k-40) may include at least one processor. For example, the control unit (1k-40) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs, and may include a multi-connection processing unit (1k-42) as illustrated in the drawing.

[0160] FIG. 1l is a diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0161] Referring to FIG. 1l, a base station according to an example of the present disclosure is configured to include an RF processing unit (1l-10), a baseband processing unit (1l-20), a backhaul communication unit (1l-30), a storage unit (1l-40), and a control unit (1l-50).

[0162] The RF processing unit (11-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (11-10) up-converts the baseband signal provided from the baseband processing unit (11-20) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (11-10) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. In the drawing, only one antenna is shown, but the base station may have multiple antennas. In addition, the RF processing unit (11-10) may include multiple RF chains. Furthermore, the RF processing unit (11-10) may perform beamforming. For the above beamforming, the RF processing unit (11-10) can adjust the phase and size of each signal transmitted and received through multiple antennas or antenna elements. The RF processing unit can perform a downlink MIMO operation by transmitting one or more layers.

[0163] The baseband processing unit (11-20) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the wireless access technology. For example, when transmitting data, the baseband processing unit (11-20) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (11-20) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (11-10). For example, in the case of OFDM, when transmitting data, the baseband processing unit (11-20) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols through IFFT operation and CP insertion. In addition, when receiving data, the baseband processing unit (11-20) divides the baseband signal provided from the RF processing unit (11-10) into OFDM symbol units, restores the signals mapped to subcarriers through FFT operation, and then restores the received bit string through demodulation and decoding. The baseband processing unit (11-20) and the RF processing unit (11-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (11-20) and the RF processing unit (11-10) may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

[0164] The above backhaul communication unit (1l-30) provides an interface for communicating with other nodes within the network. That is, the backhaul communication unit (1l-30) converts a bit string transmitted from a base station to another node, such as an auxiliary base station or a core network, into a physical signal, and converts a physical signal received from the other node into a bit string.

[0165] The storage unit (11-40) stores data such as basic programs, application programs, and setting information for the operation of the base station. In particular, the storage unit (11-40) can store information on bearers assigned to connected terminals, measurement results reported from connected terminals, and the like. In addition, the storage unit (11-40) can store information that serves as a judgment criterion for whether to provide or terminate multiple connections to a terminal. In addition, the storage unit (11-40) provides the stored data at the request of the control unit (11-50).

[0166] The control unit (11-50) controls the overall operations of the base station. For example, the control unit (11-50) transmits and receives signals through the baseband processing unit (11-20) and the RF processing unit (11-10) or through the backhaul communication unit (11-30). In addition, the control unit (11-50) records and reads data in the storage unit (11-40). For this purpose, the control unit (11-50) may include at least one processor, and may include a multi-connection processing unit (11-52) as illustrated in the drawing.

[0167] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples presented to easily explain the technical content of the present disclosure and aid in understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art to which the present disclosure pertains that other modified examples based on the technical concepts of the present disclosure are possible.

[0168] Furthermore, the above embodiments may be combined and operated as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment may be combined to operate a base station and a terminal. Furthermore, the embodiments of the present disclosure are applicable to other communication systems, and other modifications based on the technical concepts of the embodiments may also be implemented. For example, the embodiments may be applied to LTE systems, 5G, NR systems, or 6G systems. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the following claims but also by equivalents thereof.

Claims

1. In a method performed by a terminal of a wireless communication system, A step of receiving a first message including L1 (layer 1) measurement prediction setting information or L1 measurement logging setting information from a base station; A step of generating a prediction value of at least one L1 measurement result based on the L1 measurement prediction setting information or logging at least one L1 measurement result value based on the L1 measurement logging setting information; and A method comprising the step of transmitting a second message including a predicted value of at least one L1 measurement result or a logged value of at least one L1 measurement result to the base station.

2. In paragraph 1, A method characterized in that it further comprises the step of transmitting to the base station a third message including at least one of information indicating whether the terminal supports L1 measurement prediction or information indicating whether the terminal supports L1 measurement logging.

3. In paragraph 1, The above L1 measurement prediction setting information includes at least one of cell information, beam information, prediction interval, prediction period, L1 filtering, L1 filtering parameter, or reporting period, A method characterized in that the above L1 measurement logging setting information includes at least one of cell information, beam information, logging interval, logging cycle, L1 filtering, L1 filtering parameter, or reporting cycle.

4. In paragraph 1, When performing a handover or cell reselection operation, a step of transmitting a fourth message to the target base station including information indicating that the terminal stores a predicted value of the at least one L1 measurement result or the at least one logged L1 measurement result value; and A method characterized in that it further comprises the step of transmitting a fifth message including a predicted value of the at least one L1 measurement result or the logged value of the at least one L1 measurement result to the target base station based on a request of the target base station.

5. In a method performed by a base station of a wireless communication system, A step of transmitting a first message including L1 (layer 1) measurement prediction setting information or L1 measurement logging setting information to a terminal; and A method comprising the step of receiving, from the terminal, a second message including a predicted value of at least one L1 measurement result generated based on the L1 measurement prediction setting information or at least one L1 measurement result value logged based on the L1 measurement logging setting information.

6. In paragraph 5, A method further comprising the step of receiving a third message from the terminal, the third message including at least one of information indicating whether the terminal supports L1 measurement prediction or information indicating whether the terminal supports L1 measurement logging.

7. In paragraph 5, The above L1 measurement prediction setting information includes at least one of cell information, beam information, prediction interval, prediction period, L1 filtering, L1 filtering parameter, or reporting period, A method characterized in that the above L1 measurement logging setting information includes at least one of cell information, beam information, logging interval, logging cycle, L1 filtering, L1 filtering parameter, or reporting cycle.

8. In paragraph 5, If the base station is selected according to a cell reselection operation, a step of receiving a fourth message from the terminal that includes information indicating that a predicted value of the at least one L1 measurement result or a logged value of the at least one L1 measurement result is stored in the terminal; A step of transmitting a fifth message to the terminal, the fifth message including information requesting a predicted value of at least one L1 measurement result or a logged value of at least one L1 measurement result; and A method characterized in that it further comprises the step of receiving a sixth message including a predicted value of at least one L1 measurement result or a logged value of at least one L1 measurement result from the terminal.

9. In the terminal of a wireless communication system, Transmitter and receiver; and Connected to the above transmitter and receiver, Receive a first message including L1 (layer 1) measurement prediction setting information or L1 measurement logging setting information from a base station, Based on the above L1 measurement prediction setting information, generate a prediction value of at least one L1 measurement result or log at least one L1 measurement result value based on the above L1 measurement logging setting information, A terminal including a control unit that transmits a second message including a predicted value of at least one L1 measurement result or a logged value of at least one L1 measurement result to the base station.

10. In the 9th paragraph, the control unit, A terminal characterized in that it transmits to the base station a third message including at least one of information indicating whether the terminal supports L1 measurement prediction or information indicating whether the terminal supports L1 measurement logging.

11. In paragraph 9, The above L1 measurement prediction setting information includes at least one of cell information, beam information, prediction interval, prediction period, L1 filtering, L1 filtering parameter, or reporting period, A terminal characterized in that the above L1 measurement logging setting information includes at least one of cell information, beam information, logging interval, logging cycle, L1 filtering, L1 filtering parameter, or reporting cycle.

12. In the 9th paragraph, the control unit, When performing a handover or cell reselection operation, transmit a fourth message to the target base station including information indicating that the predicted value of the at least one L1 measurement result or the logged at least one L1 measurement result value is stored in the terminal, A terminal characterized in that, based on a request from the target base station, a fifth message including a predicted value of the at least one L1 measurement result or the logged at least one L1 measurement result value is transmitted to the target base station.

13. In a base station of a wireless communication system, Transmitter and receiver; and Connected to the above transmitter and receiver, Transmitting a first message including L1 (layer 1) measurement prediction setting information or L1 measurement logging setting information to the terminal, A base station including a control unit that receives, from the terminal, a second message including a predicted value of at least one L1 measurement result generated based on the L1 measurement prediction setting information or at least one L1 measurement result value logged based on the L1 measurement logging setting information.

14. In the 13th paragraph, the control unit, Receive a third message from the terminal that includes at least one of information indicating whether the terminal supports L1 measurement prediction or information indicating whether the terminal supports L1 measurement logging; The above L1 measurement prediction setting information includes at least one of cell information, beam information, prediction interval, prediction period, L1 filtering, L1 filtering parameter, or reporting period, A base station, characterized in that the above L1 measurement logging setting information includes at least one of cell information, beam information, logging interval, logging cycle, L1 filtering, L1 filtering parameter, or reporting cycle.

15. In the 13th paragraph, the control unit, If the base station is selected according to a cell reselection operation, a fourth message including information indicating that the predicted value of the at least one L1 measurement result or the logged at least one L1 measurement result value is stored in the terminal is received from the terminal, Transmitting a fifth message to the terminal, the fifth message including information requesting a predicted value of at least one L1 measurement result or a logged value of at least one L1 measurement result, A base station characterized in that it receives a sixth message including a predicted value of at least one L1 measurement result or a logged value of at least one L1 measurement result from the terminal.

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