Terminal, base transceiver station, control method, and program for efficiently measuring neighboring cells

Abstract

To improve communication efficiency by efficiently specifying radio quality of a peripheral cell.SOLUTION: Acquiring, by a terminal that performs communication with a base station based on a cellular communication standard of the 3rd Generation Partnership Project, setting information including a measurement period for measuring radio quality of a frequency from the base station, and measuring the radio quality of the frequency in the set measurement period to identify the radio quality; Providing, to a base station, predetermined information to be used in determining, by using a measurement result in a part of a measurement period, that radio quality of a frequency in another measurement period is to be estimated, the predetermined information including reconfiguration information indicating a reconfigured measurement period and information for specifying a predetermined period in which the radio quality of the frequency is to be estimated, An instruction indicating that the estimation should be performed is received from the base station, and the radio quality of the frequency is specified by using the measurement of the radio quality of the frequency in the reset measurement period and the estimation of the radio quality of the frequency in the predetermined period using the radio quality of the frequency.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a technique for measuring neighboring cells in a mobile communication system. [Background technology]

[0002] In a mobile communication system conforming to the cellular communication standard of the Third Generation Partnership Project (3GPP (registered trademark)), in order to identify a cell to which a terminal (also referred to as User Equipment, UE) can connect, the wireless quality of other cells existing around the terminal is identified. For example, a base station such as a gNB (next generation Node B) or an eNB (evolved Node B) periodically transmits a reference signal used to measure the wireless quality in the cell configured by the terminal, and indicates a period during which the reference signal should be measured. A terminal connected to the base station identifies the wireless quality of other cells by measuring frequencies other than the frequency used for communication during a set Measurement Gap (MG) period, and reports the identification result to the base station. Non-Patent Document 1 specifies the definition of measurement configuration to be set in a terminal. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS 38.331 “NR;Radio Resource Control (RRC) protocol specification” Summary of the Invention [Problem to be solved by the invention]

[0004] During the period when a terminal is performing measurements, the terminal cannot communicate with the base station to which it is connected. As a result, communication performance, such as throughput and transmission delay, decreases for the period required for measurements. Furthermore, power consumption increases when the terminal performs measurements. The present invention provides a technology for improving communication efficiency in a mobile communication system by efficiently identifying the wireless quality of neighboring cells. [Means for solving the problem]

[0005] A base station according to one embodiment of the present invention is a base station that communicates with a terminal device based on the cellular communication standard of the 3rd Generation Partnership Project (3GPP), and includes: a providing means for providing the terminal device with configuration information including a setting of a measurement period for the terminal device to measure the wireless quality of a frequency; an acquiring means for acquiring from the terminal device predetermined information regarding the wireless quality of the frequency measured during the measurement period set by the configuration information; a determining means for determining, based on the predetermined information, whether to estimate the wireless quality of the frequency during a period corresponding to another measurement period set by the configuration information using measurement results during a part of the measurement period set by the configuration information; and an instruction means for issuing an instruction to the terminal device indicating that the estimation should be performed, including reconfiguration information for reconfiguring the measurement period and information specifying a predetermined period for which the wireless quality of the frequency should be estimated, based on the result of the determination.

[0006] A terminal device according to one aspect of the present invention is a terminal device that communicates with a base station based on a cellular communication standard of the Third Generation Partnership Project (3GPP), and includes: an acquisition means that acquires from the base station configuration information including a setting of a measurement period for the terminal device to measure wireless quality of a frequency; an identification means that measures the wireless quality of the frequency in the measurement period set based on the configuration information and identifies the wireless quality; and a determination means that uses measurement results in a part of the measurement period set based on the configuration information to determine whether to estimate the wireless quality of the frequency in a period corresponding to another measurement period set by the configuration information. The method includes: a providing means for providing the base station with predetermined information to be used when the base station executes the method; and a receiving means for receiving from the base station an instruction indicating that the estimation should be performed, the instruction including resetting information indicating the measurement period that is reset based on the determination and information specifying a predetermined period during which the wireless quality of the frequency should be estimated. When the instruction is received, the identifying means identifies the wireless quality of the frequency by measuring the wireless quality of the frequency during the reset measurement period and estimating the wireless quality of the frequency during the predetermined period specified by the instruction using the wireless quality of the frequency obtained by the measurement. [Effects of the Invention]

[0007] According to the present invention, in a mobile communication system, communication efficiency can be improved by efficiently identifying the radio quality of neighboring cells. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a mobile communication system. [Figure 2] FIG. 10 is a diagram illustrating an example of the relationship between the SMTC and the MG. [Figure 3] FIG. 10 is a diagram illustrating an example of the relationship between SSB measurement settings and MG settings. [Figure 4] FIG. 10 is a diagram illustrating an example of a sequence executed between a base station and a terminal. [Figure 5]FIG. 10 is a diagram illustrating an example of a processing flow executed when a base station determines whether a prediction mode can be executed. [Figure 6] FIG. 10 is a diagram illustrating an example of the relationship between an SSB signal and an MG. [Figure 7] FIG. 10 is a diagram illustrating an example of the relationship between an SSB signal and an MG. [Figure 8] FIG. 1 illustrates an example of an extended measurement configuration. [Figure 9] FIG. 1 illustrates an example of an extended measurement configuration. [Figure 10] FIG. 1 illustrates an example of an extended measurement configuration. [Figure 11] FIG. 1 illustrates an example of an extended measurement configuration. [Figure 12] FIG. 10 is a diagram illustrating an example of a processing flow executed when a base station determines whether a prediction mode can be executed. [Figure 13] FIG. 10 is a diagram illustrating an example of a processing flow executed when a base station determines whether a prediction mode can be executed. [Figure 14] FIG. 2 is a diagram illustrating an example of the hardware configuration of a base station and a terminal. [Figure 15] FIG. 2 is a diagram illustrating an example of the functional configuration of a base station and a terminal. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0010] (System Configuration) FIG. 1 shows an example of the configuration of a mobile communication system according to this embodiment. The mobile communication system according to this embodiment is, for example, a cellular communication system conforming to the cellular communication standard of the Third Generation Partnership Project (3GPP (registered trademark)). However, this is not limited to this, and the following discussion can be applied to a mobile communication system conforming to any wireless communication standard. This mobile communication system is configured to include, for example, a terminal 101, a base station 111, a base station 112, and a base station 113. The base stations 111, 112, and 113 may be collectively referred to as base stations 110. The base station 110 exchanges radio signals with the terminal 101 via a wireless medium. The base station 110 includes, for example, a next generation Node B (gNB) and an evolved Node B (eNB). Each of the base stations 110 is connected to a core network (not shown). The core network may be, for example, an evolved packet system (EPS) or a 5G core network (5GC). The terminal 101 is a terminal used by a user and exchanges radio signals with the base station 110 via a wireless medium. The terminal 101 may be referred to as User Equipment (UE). The terminal 101 may include, for example, a smartphone, a mobile phone, a personal computer, a tablet terminal, a wearable terminal, an IoT (Internet of Things) terminal, etc. The terminal 101 may be referred to as a wireless terminal. The base station 110 and the terminal 101 may communicate using radio signals in frequency bands such as the 3.7 GHz band, the 4.5 GHz band, and the 28 GHz band. The base station 110 and the terminal 101 may also communicate using radio signals in frequency bands such as the 700 MHz band, the 800 MHz band, the 900 MHz band, the 1.5 GHz band, the 1.7 GHz band, the 2 GHz band, the 2.5 GHz band, the 3.4 GHz band, and the 3.5 GHz band. The base station 110 and the terminal 101 may also communicate using radio signals in frequency bands such as the 2.6 GHz band, the 4.9 GHz band, the 26 GHz band, and the 40 GHz band. 1, it is assumed that base station 111 and terminal 101 communicate using a first frequency, and base station 112 and base station 113 are capable of communicating with terminal 101 using frequencies other than the first frequency, such as a second frequency or a third frequency.That is, the base station 111 and the terminal 101 are in a connected state or an RRC (Radio Resource Control)_Connected state, and the base station 112 and the base station 113 are not in a connected state or are in an RRC_Idle state (or an RRC_Inactive state) with the terminal 101. Each of the first frequency, the second frequency, the third frequency, etc. may be a frequency included in the above-mentioned frequency band.

[0011] Each base station 110 constitutes a cell. A cell is, for example, a geographical area in which communication with the base station 110 that provides this cell is possible. Cell 121 provided by base station 111 communicating with terminal 101 may be referred to as a serving cell in relation to terminal 101. In FIG. 1, cells 122 and 123 formed by base station 112 and base station 113, respectively, other than the serving cell, may be referred to as neighboring cells in relation to terminal 101. A single base station may constitute multiple cells. For example, if a single base station can use multiple frequencies in parallel, different cells may be formed in each frequency. Furthermore, if a single base station can use multiple beams in parallel, different cells may be formed using each beam.

[0012] The terminal 101 may identify the wireless quality of a neighboring cell based on a notification from the base station 111, even while communicating with the base station 111. For example, the terminal 101 may identify the wireless quality of a neighboring cell by measuring the received power of a signal received from the neighboring cell. RSRP, which indicates the received power of a reference signal, may be used as a value indicating the received power of the received signal. RSRP is an abbreviation for Reference Signal Received Power. The wireless quality of a neighboring cell may be identified using information other than the received power, such as throughput, delay time, packet error rate, etc. In this embodiment, an example in which the wireless quality of a neighboring cell is identified using the received power will be described.

[0013] For example, when the terminal 101 and the base station 111 are in an RRC_Connected state, the radio quality of a neighboring cell may be identified as follows. First, the base station 111 notifies the terminal 101 to measure the received power from each base station 110. For example, the base station 111 may use an RRC Connection Reconfiguration message to notify the terminal 101 of a measurement configuration (MeasConfig) for causing the terminal 101 to perform measurement. The measurement configuration may include a measurement object (MeasObject) and a report configuration (reportConfig). The measurement configuration may also include a measurement gap (MG) configuration that indicates a period during which data is not transmitted or received in order to perform measurement. During the period in which the MG is configured, the terminal 101 may identify the radio quality of frequencies other than the first frequency.

[0014] A measurement object identifier (MeasObjectId) may be assigned to each measurement object included in a measurement configuration. For example, if multiple measurement objects are configured in one measurement configuration, each measurement object may be identified by a measurement object identifier. Each measurement object may include information specifying the frequency to be measured (ssbFrequency) and the timing to be measured (SMTC). SMTC is an abbreviation for SS / PBCH Block Measurement Timing Configuration. SS is an abbreviation for Synchronization Signal. PBCH is an abbreviation for Physical Broadcast CHannel. SMTC may be configured to include a periodicity, an offset (periodicityAndOffset), and a duration. One or more SMTCs may be configured for one frequency to be measured. For example, if multiple cells are configured in one frequency, an SMTC corresponding to each cell may be configured. The SMTC period may be expressed by the number of subframes. For example, the SMTC period can be set to 5 subframes, 10 subframes, 20 subframes, 40 subframes, 80 subframes, 160 subframes, etc. One subframe is 1 ms (msec). The duration can be set to 1 ms, 2 ms, 3 ms, 4 ms, or 5 ms.

[0015] The report configuration can be used to notify the terminal 101 of the type of trigger for a measurement report, parameters used for the trigger, the report period, the number of reports, etc. For example, when a measurement report trigger occurs in the terminal 101 (for example, when a condition for reporting is satisfied), the base station 111 can receive a measurement report from the terminal 101. The measurement report trigger can include a periodic trigger and an event trigger.

[0016] The MG settings may include an MG Length (MGL) and an MG Repetition Periodicity (MGRP). The MG may also include an offset value for specifying the start position of the MG. For example, the MGL notified by the base station 111 may be selected from among 1.5 ms, 3 ms, 3.5 ms, 4 ms, 5.5 ms, and 6 ms. On the other hand, the MGRP notified by the base station 111 may be selected from among 20 ms, 40 ms, 80 ms, and 160 ms.

[0017] When the terminal 101 receives a measurement configuration from the base station 111, the terminal 101 measures the received power of neighboring cells in accordance with the measurement configuration. For example, the terminal 101 may identify a frequency to be measured from the measurement targets included in the acquired measurement configuration and measure the received power of a signal detected at that frequency during the set MG period. The terminal 101 may perform measurements using an SSB signal included in a radio frame transmitted from the base station 110. SSB is an abbreviation for SS / PBCH Block, SS is an abbreviation for Synchronization Signal, and PBCH is an abbreviation for Physical Broadcast Channel. The SSB signal may be transmitted at different intervals in each cell. For example, the base station 110 may transmit an SSB signal in each cell it serves at an interval of 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, or 160 ms. The terminal 101 may measure received power (also referred to as Reference Signal Receive Power, RSRP) and received quality (also referred to as Reference Signal Receive Quality, RSRQ) using the received SSB signal. The terminal 101 may transmit a measurement report including the RSRP, RSRQ, etc. to the base station 111.

[0018] FIG. 2 shows the relationship between the SMTC and MG set in the measurement target. As shown in FIG. 2, the MG can be configured to include the SMTC. For example, an example will be described in which the base station 112 transmits four SSB signals, namely, a zeroth SSB signal 200, a first SSB signal 201, a second SSB signal 202, and a third SSB signal 203, at predetermined intervals. These four SSB signals can be transmitted across multiple subframes. Each SSB signal can be transmitted using the same beam or different beams. The SSB signals can also be transmitted independently across multiple frequencies. In the example of FIG. 2, the four SSB signals are transmitted across two subframes. In this case, the base station 112 can notify other base stations and terminals of information indicating the period of the two subframes in which the SSB signals are to be measured. The period in which the SSB signals are to be measured can be referred to as the SMTC window. For example, the base station 112 may notify another base station (e.g., the base station 111) of information specifying the SMTC window in the cell configured by the base station 112 using the Xn interface. For example, the SMTC window may be indicated by a cycle, an offset, and a duration in which the SMTC window should be set. The offset may be used to specify the subframe in which the SMTC window should be set. On the other hand, when the base station 111 causes the terminal 101 to measure the radio quality of the cell 122 configured by the base station 112, the base station 111 may configure measurements so that the SMTC window in the cell 122 is included. For example, the base station 111 may configure the frequency and timing to be measured so that the SMTC window in the cell 122 is included, and may also configure the MG. In the example of FIG. 2, a 4-ms MG including a 2-ms SMTC window is configured.

[0019] 3 shows an example in which MG and SSB measurement are periodically configured by the measurement configuration by base station 111. SSB measurement indicates the timing at which the SSB signal to be measured should be measured. SSB signal 210 may be SSB signal 0 200 to SSB signal 3 203 in FIG. 2. As shown in FIG. 3, SSB measurement period 301 and duration 302 may be configured to include each SSB signal 210. MG MGL 303 and MGRP 304 may be configured to include each SSB measurement period. Note that SSB measurement period 301 may be configured to include all of SSB signals 210, or may not be configured to include all of SSB signals 210.

[0020] As described above, the base station 111 configures an SSB measurement period and MG for the terminal 101 connected thereto, and causes the terminal 101 to measure the wireless quality of neighboring cells. In this case, the terminal 101 does not transmit or receive data to or from the base station 111 during the measurement period, which may result in a decrease in throughput and an increase in delay time. In contrast, if wireless quality measurements during a certain measurement period can be used to estimate wireless quality during a period corresponding to another measurement period, the terminal 101 may be able to omit part of the measurement period. For example, the terminal 101 may be able to transmit or receive data to or from the base station 111 during the period corresponding to the omitted measurement period. However, no mechanism for omitting part of the measurement period has been provided. For example, no method has been provided for the terminal 101 to configure measurements based on the assumption that wireless quality of neighboring cells can be estimated when the terminal 101 can estimate the wireless quality.

[0021] In consideration of these circumstances, the base station 111 in this embodiment uses measurement results from a part of the measurement period set by the measurement configuration to determine whether or not to estimate the radio quality of the frequency in a predetermined period corresponding to the other measurement period, and notifies the terminal 101 of information that enables the terminal to reset the measurement period in which measurements should be performed and specify the period in which estimation should be performed, based on the determination result. For example, the base station 111 provides the terminal 101 with configuration information including the configuration of the measurement period in which the terminal 101 measures the radio quality of the frequency, and acquires from the terminal 101 predetermined information related to the radio quality of the frequency measured in the measurement period set by the configuration information. Then, based on the acquired predetermined information, the base station 111 determines that estimation of the radio quality of the frequency in a period corresponding to the other measurement period set by the configuration information should be performed using measurement results from a part of the measurements set by the configuration information, and based on the determination result, notifies the terminal 101 of reconfiguration information for resetting the measurement period, information specifying the predetermined period in which the radio quality of the frequency should be estimated, and an instruction to perform estimation.

[0022] On the other hand, the terminal 101 in this embodiment measures the radio quality of the frequency during the reset measurement period and estimates the radio quality for the predetermined period using the measurement results, based on information indicating the resetting of the measurement period in which measurement should be performed and the predetermined period in which estimation should be performed, which information is notified from the base station 111. For example, the terminal 101 acquires from the base station 111 configuration information including the setting of the measurement period in which to measure the radio quality of the frequency, and provides to the base station 111 predetermined information used when the base station 111 determines that the radio quality of the frequency should be estimated during a period corresponding to another measurement period set based on the configuration information, using the measurement results for a part of the measurement period set based on the configuration information. Furthermore, the terminal 101 receives from the base station 111 a notification including reset information indicating the measurement period to be reset based on the determination and information specifying the predetermined period in which the radio quality of the frequency should be estimated, and an instruction to perform estimation. When the instruction is received, the terminal 101 determines the wireless quality of the frequency by measuring the wireless quality of the frequency during the reset measurement period and estimating the wireless quality of the frequency during the specified period specified by the instruction using the wireless quality of the frequency obtained by the measurement.

[0023] With this configuration, the base station 111 can determine that the wireless quality should be determined by estimation based on the fact that the wireless quality of the frequency in the period corresponding to the other measurement period set by the measurement configuration can be estimated using the measurement results in a part of the measurement period set by the measurement configuration, and can reset the measurement period in which the wireless quality should be measured. This enables communication between the base station 111 and the terminal 101 using resources for the period in which measurement is omitted. Furthermore, by specifying a predetermined period in which the wireless quality should be estimated using the measurement values ​​acquired in the reset measurement period, the terminal 101 can determine the wireless quality by using both measurement and estimation. This enables the terminal 101 to efficiently obtain information necessary for handover, etc. The following describes information exchanged between the terminal 101 and the base station 110 operating as described above, and examples of the configurations of each device.

[0024] (Example of a sequence between the base station 111 and the terminal 101) The operation of the base station 111 and the terminal 101 when estimating wireless quality for a period corresponding to another measurement period set by the measurement configuration using measurement values ​​acquired during a portion of the measurement period set by the measurement configuration will be described. In this embodiment, the function of the terminal 101 to estimate wireless quality for a period corresponding to another measurement period set by the measurement configuration using measurement values ​​acquired during a portion of the measurement period set by the measurement configuration will be referred to as a prediction function. Also, the operation of the terminal 101 to estimate wireless quality for a period corresponding to another measurement period set by the measurement configuration using measurement values ​​acquired during a portion of the measurement period set by the measurement configuration will be referred to as a prediction mode. Note that the measurement period in this embodiment may be, for example, an MG. Also, the measurement period in this embodiment may be, for example, an SSB measurement period (SMTC window).

[0025] 4 shows an example of a sequence of messages exchanged between the base station 111 and the terminal 101. This sequence may be executed after the terminal 101 establishes a wireless connection and an RRC connection with the base station 111 using a random access procedure, for example, based on the terminal 101 being powered on (S401). First, when the RRC connection with the terminal 101 is established, the base station 111 inquires whether the terminal 101 has a prediction function (S402). For example, the base station 111 may make the inquiry using a UE Capability Enquiry message. In response to the inquiry from the base station 111, the terminal 101 notifies the base station 111 that it has a prediction function (S403). For example, the terminal 101 may make the notification using a UE Capability Information message. In the notification indicating that it has a prediction function, the terminal 101 may notify the base station 111 of information indicating the estimation method supported by the terminal 101 and the method of calculating an evaluation value (metric) for determining whether estimation is possible. For example, the terminal 101 may notify the terminal 101 of information indicating the estimation method it supports, such as the moving average method, exponential smoothing method, regression analysis method, and estimation method using an AI model, which will be described later. Furthermore, when the terminal 101 supports multiple types of AI models for the estimation method using an AI model, the terminal 101 may notify the terminal 101 of information identifying the AI ​​model it supports. For example, the types of AI models include an AI model for estimating the wireless quality of another frequency from measurements of one frequency, an AI model for estimating the wireless quality of another period from measurements of the same frequency over a predetermined period, an AI model for estimating the wireless quality of a signal transmitted from one base station from measurements of a signal transmitted from another base station, and an AI model for estimating the wireless quality of a signal transmitted using one beam from measurements of a signal transmitted using another beam. If the terminal 101 has a prediction function, the base station 111 notifies the terminal 101 that use of the prediction mode is permitted (S404). For example, the base station 111 may notify the terminal 101 using an RRC Reconfiguration message.Note that, when the terminal 101 has a prediction function, the base station 111 may determine whether to permit the terminal 101 to use the prediction mode and may issue a notification based on the determination result. For example, the base station 111 may determine to permit the terminal 101 to use the prediction mode based on the fact that an estimation method or a metrics calculation method supported by the terminal 101 is included in the methods allowed by the base station 111 itself. For example, the base station 111 may determine not to permit the terminal 101 to use the prediction mode if the estimation method supported by the terminal 101 has low estimation accuracy. The method by which the base station 111 determines whether to permit the terminal 101 to use the prediction mode is not limited to this. For example, the base station 111 may make a determination based on the traffic situation in communication between the base station 111 itself and the terminal 101. In this case, the base station 111 may determine to permit the terminal 101 to use the prediction mode based on the amount of traffic in communication between the base station 111 itself and the terminal 101 exceeding a predetermined threshold. This increases the opportunities to allocate resources to the terminal 101, allowing the base station 111 to allocate resources necessary for communication with the terminal 101. Furthermore, the base station 111 may make a determination based on the traffic situation in the cell that the base station 111 serves. In this case, the base station 111 may determine to permit the terminal 101 to use the prediction mode based on the amount of traffic in the cell that the base station 111 serves falling below a predetermined threshold. When the amount of traffic in the cell is high, using the prediction mode may not increase opportunities to allocate resources. Therefore, not using the prediction mode may increase the accuracy of identifying the wireless quality of neighboring cells.

[0026] When the terminal 101 receives a notification from the base station 111 indicating that use of the prediction mode is permitted, the terminal 101 performs an operation to determine whether it is possible to estimate wireless quality for periods corresponding to other measurement periods set by the measurement configuration using measurement values ​​acquired during a portion of the measurement period set by the measurement configuration, and notifies the base station 111 of information about the wireless quality (S405). For example, the terminal 101 measures wireless quality for each measurement period set by the measurement configuration and notifies the base station 111 of the acquired measurement values. The terminal 101 also estimates wireless quality for periods corresponding to other measurement periods set by the measurement configuration using measurement values ​​of wireless quality acquired during a portion of the measurement period, and notifies the base station 111 of the acquired estimated value. In this case, the base station 111 may determine whether it is possible to estimate wireless quality for periods corresponding to other measurement periods set by the measurement configuration using measurement values ​​acquired during a portion of the measurement period set by the measurement configuration using the notified measurement values ​​and estimated values, and may determine whether to execute the prediction mode. Furthermore, the terminal 101 may determine whether it is possible to estimate wireless quality for periods corresponding to other measurement periods set by the measurement configuration using measurement values ​​acquired during a portion of the measurement period set by the measurement configuration, using measurement values ​​acquired during each measurement period set by the measurement configuration and estimated values ​​of wireless quality for periods corresponding to other measurement periods set by the measurement configuration estimated using a portion of the acquired measurement values. In this case, the determination result may be notified to the base station 111. The base station 111 may determine whether to execute the prediction mode based on the notified determination result. Note that the terminal 101 may determine whether it is possible to estimate wireless quality for periods corresponding to other measurement periods set by the measurement configuration using measurement values ​​acquired during a portion of the measurement period set by the measurement configuration, determine whether to execute the prediction mode based on the determination result, and request the base station 111 for permission to execute the prediction mode. In this case, the base station 111 may determine whether to permit execution of the prediction mode based on the request from the terminal 101.If the terminal 101 does not receive a notification from the base station 111 indicating that the use of the prediction mode is permitted, the terminal 101 performs measurements in each of the measurement periods set by the measurement configuration, and identifies the wireless quality.

[0027] The base station 111 determines whether to cause the terminal 101 to execute the prediction mode based on information on wireless quality acquired from the terminal 101. If the base station 111 determines to cause the terminal 101 to execute the prediction mode, the base station 111 notifies the terminal 101 of an instruction to execute the prediction mode (S406). The base station 111 may notify the terminal 101 of new setting information (reconfiguration information) for resetting the measurement period, along with the instruction to execute the prediction mode. The base station 111 may notify the terminal 101 of setting information indicating a predetermined period during which the terminal 101 should perform estimation, along with the instruction to execute the prediction mode. This setting information may be included in the instruction to execute the prediction mode, or may be notified as a separate message. If the base station 111 determines not to execute the prediction mode, the base station 111 may notify the terminal 101 of an instruction not to execute the prediction mode, or may not notify the terminal 101 of nothing.

[0028] When the terminal 101 receives an instruction from the base station 111 indicating that the prediction mode should be executed, the terminal 101 operates using the prediction mode. For example, the terminal 101 performs measurement during a reset measurement period to identify the wireless quality of neighboring cells. Furthermore, the terminal 101 identifies the wireless quality for a predetermined period notified by the base station 111 by estimation using the wireless quality of neighboring cells acquired by measurement during the reset measurement period. Then, the terminal 101 reports each of the identified wireless qualities to the base station 111 (S407). For example, the terminal 101 may report using a Measurement Report. Note that when the terminal 101 receives a notification from the base station 111 indicating that the prediction mode should not be executed or does not receive a notification from the base station 111 indicating that the prediction mode should be executed, the terminal 101 does not operate using the prediction mode. In this case, the terminal 101 performs measurement during each of the measurement periods set in the measurement configuration to identify the wireless quality of neighboring cells. Then, the terminal 101 reports the identified wireless quality in each MG to the base station 111. Furthermore, the terminal 101 can execute handover or the like based on each of the identified wireless qualities.

[0029] (Metric calculation method) FIG. 5 shows an example of an operation performed by the base station 111 when notifying the terminal 101 of an instruction to execute the prediction mode. This operation may be performed based on the base station 111 acquiring information about wireless quality from the terminal 101 in S405 of FIG. 4. In this example, the terminal 101 measures wireless quality in each measurement period set by the measurement configuration, notifies the base station 111 of the acquired measurement values, and estimates wireless quality for periods corresponding to other measurement periods set by the measurement configuration using the wireless quality measurement values ​​acquired in part of the measurement period set by the measurement configuration and notifies the base station 111 of the acquired estimated value. That is, the base station 111 acquires wireless quality measurement values ​​and estimated values ​​from the terminal 101 as information about wireless quality, and determines whether or not it is possible to estimate wireless quality for periods corresponding to other measurement periods set by the measurement configuration using the measurement values ​​acquired in part of the measurement period set by the measurement configuration, thereby determining whether or not to execute the prediction mode.

[0030] First, the base station 111 acquires from the terminal 101 the measured values ​​of the received power of neighboring cells acquired by the terminal 101 during each measurement period set by the measurement configuration, and the estimated values ​​of the received power of neighboring cells estimated by the terminal 101 using the measured values ​​(S405). Then, the base station 111 calculates a metric using the measured values ​​and the estimated values ​​acquired from the terminal 101 (S501). For example, the base station 111 may determine that estimation is possible for at least one measurement period among the measurement periods set by the measurement configuration, based on the fact that the difference between the estimated value of wireless quality estimated based on the measured values ​​during other measurement periods set by the measurement configuration and the measured value during at least one measurement period is smaller than a predetermined threshold. As an example, when the base station 112 forms a cell at the second frequency, an example will be described with reference to FIG. 6 in which the base station 111 determines whether it is possible to estimate the received power of other SSB signals using part of the measured values ​​of the received power of SSB signals transmitted by the base station 112 at the second frequency. 6, SSB signals 601-605 each represent an SSB signal periodically transmitted by base station 112. MGs 611-615 represent subframes in which MGs for terminal 101 are configured on the radio frame of the cell served by base station 111. MGs 611-615 can be configured in this manner so that terminal 101 can measure the received power of each SSB signal 601-605 at the timing when each SSB signal is transmitted. MGs 611-615 can be configured based on the setting of an SSB measurement period configured for measuring SSB signals 601-605. Terminal 101 measures the received power of SSB signals 601-605 in MGs 611-615, respectively, and reports the results to base station 111. Terminal 101 can also estimate the received power of SSB signals 603 and 604 using, for example, the measured values ​​of SSB signals 601 and 602, and report the results to base station 111. The terminal 101 may report the measured values ​​and estimated values ​​to the base station 111 using a Measurement Report, or may use separate messages for notifying each of them.

[0031] For example, the base station 111 uses the difference between the measured value and estimated value of the SSB signal 603 acquired from the terminal 101 as an evaluation value (metric) and determines whether this difference is equal to or less than a predetermined threshold. If the difference between the measured value and estimated value of the SSB signal 603 is equal to or less than the predetermined threshold, the base station 111 may determine that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement configuration using the measured value acquired during a portion of the measurement period set by the measurement configuration. Furthermore, if the difference between the measured value and estimated value of the SSB signal 603 is not equal to or less than the predetermined threshold, the base station 111 may determine that it is not possible to estimate the received power for a period corresponding to another measurement period set by the measurement configuration using the measured value acquired during a portion of the measurement period set by the measurement configuration. Note that the base station 111 may make this determination using the measured value and estimated value of the SSB signal 604 in addition to the measured value and estimated value of the SSB signal 603. For example, the base station 111 may determine that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement setting using measurements acquired during a portion of the measurement period set by the measurement setting, based on the fact that both the difference between the measured value and the estimated value of the SSB signal 603 and the difference between the measured value and the estimated value of the SSB signal 604 are equal to or less than a predetermined threshold. That is, the base station 111 may determine that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement setting using measurements acquired during a portion of the measurement period set by the measurement setting, based on the fact that all or a predetermined percentage or more of the calculated differences between one or more measured values ​​and estimated values ​​are equal to or less than a predetermined threshold. Furthermore, the base station 111 may determine that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement setting using measurements acquired during a portion of the measurement period set by the measurement setting, based on the fact that the difference between the statistical value of the measured values ​​of multiple SSB signals and the statistical value of the estimated values ​​of these signals is equal to or less than a predetermined threshold. Here, the statistical value may be, for example, but is not limited to, a sum, a weighted sum, an average, a weighted average, a maximum value, etc.In this example, the received power of two SSB signals 603 and 604 is estimated based on the measured values ​​of two SSB signals 601 and 602. However, one or more measured values ​​may be used for the estimation, and one or more received power may be estimated. Furthermore, three or more measured values ​​or three or more estimated values ​​may be used to calculate the evaluation value. For example, the base station 111 may calculate the evaluation value over a certain period and determine whether the calculated evaluation value satisfies a predetermined condition, thereby determining whether it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement setting using the measured values ​​acquired during a portion of the measurement period set by the measurement setting. As an example, the base station 111 may determine that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement setting using the measured values ​​acquired during a portion of the measurement period set by the measurement setting based on, for example, whether the average of the evaluation values ​​calculated over the certain period is equal to or less than a predetermined threshold, or whether a predetermined percentage of the evaluation values ​​calculated over the certain period is equal to or less than a predetermined threshold.

[0032] Note that if there is a certain correlation in the radio quality between SSB signals transmitted at each of multiple frequencies, it is also possible to estimate the radio quality of an SSB signal at one frequency using the measured value of the SSB signal at another frequency. For example, when base station 112 configures cells using a second frequency and a third frequency, an example will be described with reference to FIG. 7 in which base station 111 determines whether it is possible to estimate the received power of an SSB signal transmitted at the cell at the third frequency using part of the measured value of the received power of an SSB signal transmitted at the cell at the second frequency. In FIG. 7, SSB signals 701, 703, and 705 each represent an SSB signal periodically transmitted at the cell at the second frequency. Furthermore, SSB signals 702 and 704 each represent an SSB signal periodically transmitted at the cell at the third frequency. Furthermore, MGs 711 to 715 represent subframes in which MGs for terminal 101 are set on the radio frame of the cell provided by base station 111. Note that MGs 711 to 715 may be configured based on the configuration of an SSB measurement period configured for measuring SSB signals 701, 703, and 705 and the configuration of an SSB measurement period configured for measuring SSB signals 702 and 704. In this case, terminal 101 may measure the received power of SSB signals 701, 703, and 705 transmitted in a cell of the second frequency in MGs 711, 713, and 715. Terminal 101 may also measure the received power of SSB signals 702 and 704 transmitted in a third frequency in MGs 712 and 714. Terminal 101 may measure the received power of SSB signals 701 to 705 in each of MGs 711 to 715 and report the results to base station 111, for example. Furthermore, terminal 101 estimates the received power of SSB signals 702 and 704 using the measured values ​​of SSB signals 701 and 703, and reports this to base station 111. Base station 111 then uses the difference between the measured value of SSB signal 703 obtained from terminal 101 and the estimated value as an evaluation value (metric), and determines whether this difference is equal to or smaller than a predetermined threshold.If the difference between the measured value and the estimated value of the SSB signal 702 is equal to or smaller than a predetermined threshold, the base station 111 may determine that it is possible to estimate the wireless quality for the period corresponding to the measurement period corresponding to the third frequency using the measured value acquired in the measurement period corresponding to the second frequency. Furthermore, if the difference between the measured value and the estimated value of the SSB signal 702 is not equal to or smaller than the predetermined threshold, the base station 111 may determine that it is not possible to estimate the wireless quality for the period corresponding to the measurement period corresponding to the third frequency using the measured value acquired in the measurement period corresponding to the second frequency. The method by which the base station 111 determines whether it is possible to estimate the wireless quality for the period corresponding to the measurement period corresponding to the third frequency using the measured value acquired in the measurement period corresponding to the second frequency is not limited to this, and any method corresponding to the method described in the example shown in FIG. 6 may be similarly applied.

[0033] The base station 111 may determine that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement configuration using measurements acquired during a portion of the measurement period set by the measurement configuration, based on the fact that the difference between a measurement value for at least one measurement period set by the measurement configuration and a measurement value for another measurement period set within a predetermined period from the measurement period is smaller than a predetermined threshold. For example, the measurement period can be increased in situations where the terminal 101 is used in a fixed location and therefore has low mobility, or in situations where there is little change in the environment around the terminal 101. The base station 111 may detect such a situation of the terminal 101 by evaluating the difference between multiple measurement values ​​acquired within a predetermined period. For example, in FIG. 6, the base station 111 may determine that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement configuration using measurements acquired during a portion of the measurement period set by the measurement configuration, based on the fact that the difference between the measurement value of SSB signal 601 and the measurement values ​​of SSB signals 602, 603, 604, or 605 is smaller than a predetermined threshold. Furthermore, in FIG. 7, the base station 111 may determine that it is possible to estimate the wireless quality at the third frequency using the measurements obtained at the second frequency based on the fact that the difference between the measurements of SSB signals 701, 703, and 705 and the measurements of SSB signals 702 and 704 is smaller than a predetermined threshold.

[0034] If the terminal 101 supports multiple estimation methods (including multiple inference models), the base station 111 may evaluate each of them in parallel to determine whether it is possible to estimate the received power in a period corresponding to another measurement period set by the measurement configuration using measured values ​​acquired in a part of the measurement period set by the measurement configuration. If the base station 111 supports multiple metric calculation methods, the base station 111 may evaluate each of them in parallel to determine whether it is possible to estimate the received power in a period corresponding to another measurement period set by the measurement configuration using measured values ​​acquired in a part of the measurement period set by the measurement configuration. If it is determined that estimation is possible using multiple estimation methods, the estimation method with a relatively high evaluation value of the calculated metric (for example, a small difference between the measured value and the estimated value) may be selected. Note that an estimation formula or an inference model may be provided from the base station 111 to the terminal 101. Alternatively, the base station 111 may estimate the received power of a neighboring cell using measured values ​​acquired from the terminal 101 on behalf of the terminal 101, and calculate the metric using the acquired estimated value. In this case, the base station 111 may calculate the metric using an estimation method supported by the terminal 101. This allows the base station 111 to determine whether it is possible to estimate the received power in a period corresponding to another measurement period set by the measurement configuration using a method that the terminal 101 can use for estimation, using measured values ​​acquired in a part of the measurement period set by the measurement configuration. For example, the base station 111 can acquire information indicating the estimation method supported by the terminal 101 and the calculation method of an evaluation value (metric) for determining whether estimation is possible in S403 of FIG.

[0035] (Determining whether prediction mode can be executed) When the base station 111 determines that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement configuration using the measurement values ​​acquired during a portion of the measurement period set by the measurement configuration, the base station 111 determines whether to cause the terminal 101 to start operating in the prediction mode (S502). For example, the base station 111 may determine to cause the terminal 101 to start operating in the prediction mode based on the determination that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement configuration using the measurement values ​​acquired during a portion of the measurement period set by the measurement configuration. The base station 111 may also determine to cause the terminal 101 to start operating in the prediction mode based on the fact that a value indicating the amount of traffic communicating with the terminal 101 exceeds a predetermined threshold. The value indicating the amount of traffic may be the frequency of downlink or uplink traffic, the amount of data communicated within a certain period, the usage rate of wireless resources, the average value of transmission delay, etc. When the amount of traffic communicating between the base station 111 and the terminal 101 is large, using the prediction mode reduces the period during which the terminal 101 performs measurements, thereby increasing the opportunity for resource allocation to the terminal 101. On the other hand, when the amount of traffic communicating between the base station 111 and the terminal 101 is not large, the prediction mode is not used, thereby allowing the terminal 101 to more accurately identify the wireless quality of neighboring cells and connect the terminal 101 to an appropriate cell. Note that the base station 111 may determine not to cause the terminal 101 to start operating in the prediction mode based on the fact that a value indicating the amount of traffic in the cell configured by the base station 111 exceeds a predetermined threshold. For example, when the number of terminals connected to the cell configured by the base station 111 is large, and opportunities for resource allocation to the terminal 101 do not increase even if the terminal 101 operates in the prediction mode, the prediction mode is not used, thereby allowing the terminal 101 to more accurately identify the wireless quality of neighboring cells and connect the terminal 101 to an appropriate cell.

[0036] When the base station 111 determines that the terminal 101 should start operating in the predictive mode, the base station 111 sends a first notification to the terminal 101 instructing the terminal 101 to start operating in the predictive mode (S406). For example, the base station 111 may send the first notification using a downlink RRC message, MAC CE, DCI, or the like. In addition, the base station 111 may send information indicating resetting of the measurement configuration to the terminal 101 in the first notification. That is, by causing the terminal 101 to operate in the predictive mode, the base station 111 recognizes that part of the measurement period set for measuring the radio quality of neighboring cells becomes unnecessary. Based on this, the base station 111 resets the measurement configuration for the terminal 101, which may increase the opportunities to allocate resources to the terminal 101. For example, if base station 111 determines that the received power of SSB signals 602 and 604 can be estimated using the measured values ​​of SSB signals 601 and 603 in Fig. 6, it may notify terminal 101 of a measurement configuration in which the cycle of the SSB measurement period is doubled or the MGRP is doubled as reconfiguration information. Also, if base station 111 determines that the received power of SSB signals 702 and 704 can be estimated using the measured values ​​of SSB signals 701 and 703 in Fig. 7, it may notify terminal 101 of a measurement configuration in which the measurement target (including the SSB measurement period) corresponding to the third frequency is deleted and the MGRP is doubled.

[0037] In the prediction mode, the terminal 101 estimates the received power for a period corresponding to the measurement period reduced by resetting the measurement configuration. The base station 111 may notify the terminal 101 of information specifying the period or timing for which the terminal 101 should perform estimation, in conjunction with the first notification. For example, the base station 111 may explicitly notify the terminal 101 of the target for which the terminal 101 should estimate wireless quality in the first notification. For example, the base station 111 may notify the terminal 101 of the frequency to be estimated (ssbFrequency, ARFCN-ValueNR), the timing to be estimated (periodicityAndOffset), etc., as the target for which wireless quality should be determined, using an estimation configuration that uses the same configuration as the measurement configuration. The base station 111 may also notify the terminal 101 of information that can identify an estimation formula, an inference model, etc. to be used for estimation, and information that can identify measurement values ​​to be used for estimation. If the terminal 101 determines that it is in a state where it can estimate the received power for a period corresponding to another measurement period set by the measurement configuration using measurements acquired during a portion of the measurement period set by the measurement configuration, the terminal 101 may identify the measurement values ​​to be used for estimation by being notified of the estimation configuration. On the other hand, if the base station 111 determines that it is in a state where it can estimate the received power for a period corresponding to another measurement period set by the measurement configuration using measurements acquired during a portion of the measurement period set by the measurement configuration, the base station 111 may notify the terminal 101 of information indicating the target to be estimated, as well as information that can identify the measurement values ​​to be used for estimation and the method or model to be used for estimation. The base station 111 may also implicitly notify the terminal 101 of information that identifies the period during which the terminal 101 should perform estimation. For example, the base station 111 may implicitly notify the terminal 101 that it should estimate the received power for a period corresponding to the measurement period reduced by the reconfiguration, by resetting the measurement configuration in accordance with the first notification. In this case, the terminal 101 receives an instruction to make an inference, and based on the fact that the period for which the inference should be made is not explicitly indicated, it can recognize the object to be inferred by extracting the difference between the measurement object set in the measurement configuration before the reconfiguration and the measurement object set by the reconfiguration.In this way, when the period for which estimation should be performed is implicitly notified, the instruction to perform estimation can be information specifying the period for which the terminal 101 should perform estimation. Note that the base station 111 may acquire from the terminal 101 measurements measured based on the measurement configuration after reconfiguration, and estimate the wireless quality for the period corresponding to the measurement period reduced by the reconfiguration. In this case, the wireless quality acquired by the base station 111 estimation can be notified from the base station 111 to the terminal 101.

[0038] (Method of notifying measurement settings when resetting) The base station 111 may use an extended measurement configuration when reconfiguring the measurement configuration in accordance with the first notification. For example, in the measurement configuration in the conventional 3GPP cellular communication standard, it is specified that a single value is set as the SSB measurement period period (periodicityAndOffset) and the MG period (MGRP). That is, it is assumed that the SSB measurement period period and the MG period are constant. On the other hand, as described above, for example, if it is determined that the radio quality of SSB signals 603 and 604 can be estimated using the measured values ​​of SSB signals 601 and 602 in FIG. 6, the SSB measurement period period may not be constant. Similarly, the period to be set in the MG configuration may not be constant. For this reason, the conventional 3GPP cellular communication standard does not support such SSB measurement period and MG configuration. Therefore, the base station 111 in this embodiment may set multiple values ​​as the SSB measurement period period and the MGRP in the measurement configuration.

[0039] 8 shows an example in which the base station 111 notifies two values ​​as the period of the SSB measurement period when setting the SSB measurement period. In FIG. 8, the base station 111 performs measurements using the SSB signal 210 at t=0, 1, and 4, and determines that the radio quality of the SSB signal 210 at t=2 and 3 can be estimated using the acquired measurements. In this case, the base station 111 may notify the terminal 101 of a first period 801 and a second period 802 as the period of the SSB measurement period. For example, the base station 111 may notify the terminal 101 of a setting such as periodicity[sf5, sf15]Offset0 as periodicityAndOffset. Note that sf5 indicates that the first period 801 is 5 subframes and the second period 802 is 15 subframes. In this case, assuming that duration 302 in the reset measurement configuration is constant, terminal 101 can determine that measurement should be performed in period 803 based on the notified first period 801 and second period 802. Note that if the period of the SSB measurement period is configured using a third period and a fourth period in addition to first period 801 and second period 802, base station 111 can notify terminal 101 of values ​​corresponding to each period. In other words, as long as the period of the SSB measurement period is expressed as a combination of multiple periods, base station 111 can notify terminal 101 of the period of the SSB measurement period using one or more values ​​corresponding to each of those periods. Furthermore, base station 101 can notify terminal 101 of the period in which estimation should be performed (estimation timing in estimation configuration) 804 in FIG. 8, i.e., the period during which measurement is not performed, using an expression similar to that used in the extended measurement configuration. In this case, a setting such as periodicity [sf5, sf15] Offset N may be notified to the terminal 101 as periodicityAndOffset, which is the period for which estimation should be performed. Here, N is an offset for adjusting the start time of the period for which estimation should be performed so that t=2.

[0040] As with the SSB measurement period configuration, the base station 111 may also notify the terminal 101 of multiple values ​​for the MG configuration as MGRP. For example, as shown in FIG. 9, the base station 111 may notify the terminal 101 of a measurement period 803 using a first MGRP 901 and a second MGRP 902. As an example, the base station 111 may notify the terminal 101 of a configuration such as [40 ms, 120 ms] as the MGRP value. In this case, the terminal 101 may recognize that the first MGRP is 40 ms and the second MGRP is 120 ms. As with the SSB measurement period cycle, if the MG to be configured is configured using three or more cycles, the base station 111 may notify the terminal 101 of three or more values ​​corresponding to each of those cycles as the MGRP configuration. Furthermore, the base station 101 may notify the terminal 101 of the period 804 for which estimation should be performed in FIG. 9, i.e., the period during which measurement is not performed, using an expression similar to that for the extended measurement configuration. In this case, as the MGRP that sets the period in which the wireless quality should be determined by estimation, a setting such as [40 ms, 120 ms] Offset N can be notified to the terminal 101. Here, N is an offset for adjusting so that t=2 is the start time of the period in which estimation should be performed.

[0041] The extended measurement configuration used by the base station 111 when the SSB measurement period does not have a fixed period is not limited to the above. For example, the base station 111 may add a bitmap representation indicating whether each SSB measurement period is valid or invalid to the measurement configuration in the conventional 3GPP cellular communication standard. For example, as shown in FIG. 10, the base station 111 may notify the bitmap value "1100" to indicate that the SSB measurement period in period 803 is valid and the SSB measurement period in period 804 is invalid. In this case, the terminal 101 may determine whether each SSB measurement period is valid or invalid based on the notified bitmap and perform measurements in the SSB measurement periods determined to be valid. Furthermore, the terminal 101 may recognize that wireless quality should be determined by estimation when an SSB measurement period is invalid.

[0042] Similarly, as shown in FIG. 11 , the base station 111 may notify the terminal 101 of the measurement configuration by adding a bitmap to the MG configuration in the conventional 3GPP cellular communication standard. For example, the base station 111 may notify the terminal 101 of the measurement configuration by adding a bitmap value of “1100” to indicate that the MG in period 803 is enabled and the MG in period 804 is disabled. In this case, the terminal 101 may determine whether each MG is enabled or disabled based on the notified bitmap and perform measurements in the MG determined to be enabled. Furthermore, when an MG is disabled, the terminal 101 may recognize that the wireless quality should be determined by estimation. Note that the base station 111 may notify the terminal 101 of a common bitmap that is applied to both the SSB measurement period configuration and the MG configuration. This makes it possible to reduce the amount of information notified from the base station 111 to the terminal 101 and avoid inconsistencies between the SSB measurement period configuration and the MG configuration. Note that the SSB measurement period and the MG configuration may be configured independently. For example, the base station 111 may reconfigure the SSB measurement period without changing the MG settings. In this case, the base station 111 may recognize that the period set in the SSB measurement period for the configured MGs is the period during which measurements should be performed, and that the other MGs are the periods during which estimation should be performed without performing measurements.

[0043] (Behavior when running prediction mode) Returning to Fig. 5, the explanation will be continued. The terminal 101 may start operation in the prediction mode based on receiving the first notification from the base station 111 (S503). Furthermore, the terminal 101 may reset the target to be measured or set the target to be estimated based on the measurement configuration reset information and information indicating a predetermined period for which estimation should be performed, which are notified from the base station 111. Then, the terminal 101 may measure and estimate the wireless quality of neighboring cells based on the settings.

[0044] The base station 111 communicates with the terminal 101 based on the reset measurement configuration. For example, the base station 111 can perform scheduling by using resources for communication with the terminal 101 in a period corresponding to the measurement period reduced by resetting the measurement configuration. Furthermore, the terminal 101 communicates with the base station 111 based on scheduling notified by the base station 111. For example, the terminal 101 can transmit HARQ feedback, a Scheduling Request (SR), Channel State Information (CSI), a report Sounding Reference Signal (SRS), an UpLink Shared CHannel (UL-SCH) other than message 3 in the random access procedure, and the like. Furthermore, the terminal 101 can receive a DownLink Shared CHannel (DL-SCH), or monitor a Physical Layer Downlink Control CHannel (PDCCH) other than when the terminal device is waiting to receive message 2 or message 4 during the random access procedure. On the other hand, the base station 111 can transmit DCI indicating scheduling of a Physical Layer Downlink Shared CHannel (PDSCH) and a Physical Layer Uplink Shared CHannel (PUSCH), transmit the PDSCH based on the scheduling, receive the PUSCH, etc. This increases the resources that the terminal 101 can use for communication with the base station 111 compared to when measurements of neighboring cells are performed in all measurement periods set without using a prediction mode, making it possible to improve throughput, reduce delay time, etc. Note that the base station 111 and the terminal 101 may use resources in periods corresponding to measurement periods reduced by reconfiguring the measurement periods for purposes other than those described above.

[0045] (How to estimate wireless quality) A method in which terminal 101 uses measured values ​​for a measurement period set by the measurement configuration to estimate wireless quality for a period corresponding to another measurement period set by the measurement configuration will be described below. First, an example in which terminal 101 uses some of the measured values ​​of an SSB signal periodically transmitted at one frequency to estimate the wireless quality of another SSB signal at the same frequency will be described with reference to FIG. 6. For example, assume that multiple SSB signals are periodically transmitted at one frequency, such as SSB signals 601 to 605 shown in FIG. 6. In this case, terminal 101 may estimate the received power of the Nth SSB signal transmitted by using the average value of one or more previously measured received power values ​​(e.g., N-1, N-2, N-3, ...). This estimation method may be called a moving average method. For example, terminal 101 may estimate the average value of the measured values ​​of SSB signals 601 to 603 as the received power of SSB signal 604. Next, terminal 101 may estimate the average value of the measurement values ​​of SSB signals 602 to 604 as the received power of SSB signal 605. In this way, terminal 101 may successively perform estimation using a moving average of past measurement values ​​of SSB signals. When terminal 101 measures SSB signals 601, 603, and 605, terminal 101 may estimate the average value of the measurement values ​​of SSB signals 601 and 603 as the received power of SSB signal 604. In this case, terminal 101 may estimate the average value of the measurement values ​​of SSB signals 603 and 605 as the received power of the SSB signal following SSB signal 605. Alternatively, terminal 101 may estimate the average value of the measurement values ​​of SSB signals 601 and 603 as the received power of SSB signal 602. Furthermore, when terminal 101 measures SSB signals 601, 602, 604, and 605, it may estimate the average value of the measurements of SSB signals 601 and 602 as the received power of SSB signal 603. Alternatively, terminal 101 may estimate the average value of the measurements of SSB signals 601, 602, and 604 as the received power of SSB signal 603. Terminal 101 may also make the estimation using a weighted average in which a greater weight is assigned to the measurements of SSB signals that are closer to the SSB signal whose received power is to be estimated.

[0046] Terminal 101 may use the measured value of the SSB signal transmitted the (N-1)th time and the estimated value of this SSB signal to weight and estimate the radio quality of the SSB signal transmitted the Nth time. This estimation method may be called exponential smoothing. In this case, the following estimation formula may be used: (estimated value of the SSB signal transmitted the Nth time) = α × (measured value of the SSB signal transmitted the (N-1)th time) + (1 - α) × (estimated value of the SSB signal transmitted the (N-1)th time), (0 < α < 1). For example, in FIG. 6, SSB signal 605 may be estimated based on the measured value of the received signal of SSB signal 604 and the estimated value of SSB signal 604. Note that terminal 101 measures SSB signals 601, 603, and 605, and when estimating SSB signal 602, it may estimate the received power of SSB signal 604 using exponential smoothing using the measured value of SSB signal 603 and the estimated value of SSB signal 602.

[0047] The terminal 101 may estimate the received signal using a regression line determined based on the measured values ​​of the SSB signal. For example, if the terminal 101 obtains the measured values ​​in Table 1 by measuring the SSB signal, the terminal 101 may determine the regression line y=0.3071x-114.21 as the estimation formula. This estimation method may be called a regression analysis method. The terminal 101 may determine the estimated value y of the received power by applying a time corresponding to a predetermined period to be estimated to the variable x of this regression line. Note that the terminal 101 may update the regression line using measured values ​​obtained while the prediction mode is being executed.

[0048] Table 1 TIFF2026030319000002.tif124160

[0049] The terminal 101 can estimate the wireless quality of other SSB signals by applying the measured values ​​of the SSB signals as input to a trained model (inference model) generated by machine learning. In this embodiment, a method of making an estimation using a trained model is referred to as an estimation method using an AI model. For example, the terminal 101 performs machine learning using one or more first data from the measured values ​​acquired during each measurement period set by the measurement configuration as input data for training data for machine learning and one or more second data as correct answer data for the training data. The first data may be measured values ​​for a measurement period corresponding to the measurement period that will continue to be set when the measurement configuration for the prediction mode is reset, and the second data may be measured values ​​for a measurement period corresponding to the measurement period that will be estimated (i.e., reduced) when the measurement configuration for the prediction mode is reset. For example, suppose that the base station 111 determines whether the received power of SSB signals 603 and 604 can be estimated using measured values ​​for SSB signals 601 and 602 in FIG. 6. In this case, when four consecutive MGs that are periodically set are grouped into one group, the received power measured in the first two MGs (corresponding to SSB signals 601 and 602) in that group may correspond to input data in the training data, and the received power measured in the last two MGs (corresponding to SSB signals 603 and 604) may correspond to correct data in the training data. Terminal 101 may apply, for example, SSB signals 601 and 602 as input to a trained model (inference model) generated using such training data, and obtain estimated values ​​of the received power of SSB signals 603 and 604 as output. Terminal 101 may generate multiple inference models and select one of them to execute the prediction mode. When using machine learning to estimate wireless quality, the training data to be used for training may differ depending on the surrounding environment.Therefore, base station 111 generates multiple trained models by changing the combination of measurement values ​​used as input data for training data and measurement values ​​used as correct data from the measurement values ​​acquired during each measurement period, calculates metrics using each trained model, and can determine whether or not each model can make inferences.

[0050] When cells are formed at multiple frequencies, terminal 101 may use measurements of SSB signals transmitted at some frequencies to estimate the radio quality of SSB signals at other frequencies. For example, as shown in FIG. 7, assume that base station 112 forms cells using a second frequency and a third frequency. In this case, terminal 101 may estimate the received power of SSB signals 702 and 704 at the third frequency, for example, based on measurements of SSB signals 701 and 703 received at the second frequency. For example, terminal 101 measures the received power of SSB signals transmitted from base station 112 at the second frequency and the third frequency within a certain period of time. Terminal 101 uses the acquired measurements to identify a correlation (an estimation formula) between the measured values ​​at the second frequency and the measured values ​​at the third frequency. For example, terminal 101 generates an approximation curve using the least squares method. Terminal 101 then estimates the received power at the third frequency from the measured values ​​at the second frequency based on the identified estimation formula. For example, the terminal 101 estimates the received power of the SSB signal 702 by applying the measured values ​​of the SSB signal 701 to an approximation curve.

[0051] Terminal 101 may also use a machine learning estimation method when using measurements of SSB signals transmitted at some frequencies to estimate the radio quality of SSB signals at other frequencies. For example, when measuring the radio quality of SSB signals 701 and 703 in FIG. 7 to estimate the received power of SSB signals 702 and 704, the received power measured at the second frequency may correspond to input data in the training data, and the received power measured at the third frequency may correspond to correct data in the training data. Terminal 101 may apply, for example, the measured values ​​of SSB signals 701 and 703 as input to a trained model (inference model) generated using such training data, and obtain estimated values ​​of the received power of SSB signals 702 and 704 as output.

[0052] Terminal 101 may use measurements in a cell formed by a given base station to estimate the wireless quality of a cell formed by another base station. An example in which terminal 101 uses measurements in a cell formed by base station 112 to estimate the received power of a cell formed by base station 113 will be described with reference to FIG. 6. Assume that, in FIG. 6, SSB signals 601, 603, and 605 are transmitted in cell 122 formed by base station 112, and SSB signals 602 and 604 are transmitted in cell 123 formed by base station 113. In this case, terminal 101 performs machine learning using the measurements of the SSB signals transmitted in cell 122 as input data in the training data and the SSB signals transmitted in cell 123 as correct answer data in the training data, thereby obtaining a trained model (inference model). Terminal 101 then inputs the measurements of SSB signals 601 and 603 as inputs to this inference model, and can obtain estimated values ​​of the received power of SSB signals 602 and 604 as output. In this way, the terminal 101 can estimate the radio quality of the cell formed by the base station 113 using measurements in the cell formed by the base station 112 .

[0053] Furthermore, if one base station 110 is capable of forming multiple beams, each cell may be formed using each beam. In this case, SSB signals may be transmitted at different times in each cell. In this case, terminal 101 may use measurement values ​​of SSB signals transmitted by some beams to estimate the radio quality of SSB signals transmitted by other beams. For example, assume that base station 112 is capable of forming four beams (beam 0 to beam 3) and that SSB signals 200 to 203 in FIG. 2 are transmitted by each beam. In this case, terminal 101 may perform machine learning using the measurement values ​​of SSB signals transmitted by beam 0 and beam 1 as input data in the training data and the measurement values ​​of SSB signals transmitted by beam 2 and beam 3 as correct answer data in the training data, thereby acquiring a trained model (inference model). Terminal 101 may then input the measurement values ​​of SSB signals 200 and 201 as inputs to this inference model and acquire estimated values ​​of the received power of SSB signals 202 and 203 as outputs. In this case, since it is no longer necessary to measure SSB signals 202 and 203, a portion of one measurement period can be utilized for other purposes. For example, terminal 101 can use resources corresponding to the measurement of SSB signals 202 and 203 for communication with base station 111. In this case, base station 111 can reconfigure the duration of the MGL and SSB measurement period required for measurement to terminal 101. For example, base station 111 can notify two values ​​as the duration values ​​of the MGL and SSB measurement period. Terminal 101 can recognize that one of the notified values ​​corresponds to a period during which measurement should be performed and the other corresponds to a period during which estimation should be performed without measurement. Note that base station 111 may notify three or more values ​​as the duration values ​​of the MGL and SSB measurement period. In this case, each duration can be associated with either a period during which measurement should be performed or a period during which estimation should be performed without measurement. For example, the first period may be associated with a period in which measurement should be performed, and the second period may be associated with a period in which estimation should be performed without measurement, and thereafter, periods in which measurement should be performed and periods in which estimation should be performed without measurement may be alternately associated.

[0054] In this way, the terminal 101 can estimate the wireless quality for a predetermined period notified by the base station 111 using the wireless quality measurement values ​​for a set measurement period by selecting and using an appropriate estimation method from various estimation methods according to the surrounding wireless environment. Note that the above is an example of a wireless quality estimation method that can be performed by the terminal 101, and the present invention is not limited to this. For example, more measurement values ​​or different types of measurement values ​​can be used to generate an estimation formula or an inference model. For example, a time series of each measurement value can be used. Also, measurement values ​​acquired at two or more frequencies can be used. Also, a combination of the above parameters or other parameters may be used to generate the inference model. For example, a time series of measurement values ​​of SSB signals transmitted at two or more frequencies using multiple beams different from each other can be used as training data. Also, location information of the terminal 101 may be used as input data for training data for generating the inference model or as input data for making inferences. Also, a combination of two or more of the above estimation formulas and inference models may be used. Also, although the above description uses an example in which the terminal 101 generates the estimation formula or inference model, the estimation formula or inference model may be provided to the terminal 101 from the base station 111. In this case, the terminal 101 can estimate the wireless quality of the SSB signal using an estimation formula or an inference model provided by the base station 111.

[0055] (Behavior when prediction mode ends) After starting operation in the prediction mode based on receiving a first notification from the base station, the terminal 101 may become unable to estimate the wireless quality for the notified predetermined period using measurement values ​​acquired during the reconfigured measurement period. For example, after starting operation in the prediction mode, the difference between the environment in which the estimation formula or inference model used for estimation can be applied and the actual communication environment may become greater over time. In response to this, the base station 111 may continuously determine whether it is possible to estimate the wireless quality for the notified predetermined period using measurement values ​​during the configured measurement period, even while the prediction mode is being executed. That is, the base station 111 may determine whether it is possible to estimate the wireless quality for the notified predetermined period using measurement values ​​during the configured measurement period in order to determine whether to terminate the prediction mode. For example, when reconfiguring the measurement settings, the base station 111 may configure the settings so that a measurement period used to determine whether to terminate the prediction mode is included. The terminal 101 may measure and estimate the wireless quality for the measurement period used to determine whether to terminate the prediction mode, and report the results to the base station 111. The base station 111 may then determine whether to terminate the prediction mode using the measurement values ​​and estimated values ​​acquired for the measurement period used to determine whether to terminate the prediction mode. If the base station 111 determines that it is not possible to estimate the wireless quality for the notified predetermined period using the measurement values ​​for the set measurement period, the base station 111 may transmit a second notification to the terminal 101 instructing the terminal 101 to terminate the prediction mode. In conjunction with the second notification, the base station 111 may transmit information for further reconfiguring the measurement configuration. For example, the information for further reconfiguring the measurement configuration may be the same as or different from the measurement configuration before the terminal 101 executes the prediction mode. For example, the base station 111 may reconfigure the measurement configuration based on information about neighboring cells acquired while the terminal 101 executes the prediction mode. Upon receiving the second notification instructing the terminal 101 to terminate the prediction mode, the terminal 101 performs measurements in each of the measurement periods set by the measurement configuration.

[0056] In addition, when a cell is configured for each of a plurality of frequencies, the base station 111 may estimate the radio quality of the remaining plurality of frequencies using measured values ​​for some of the frequencies in a prediction mode. At this time, if it is determined that the radio quality of some of the frequencies included in the remaining plurality of frequencies cannot be estimated, the base station 111 may cause the terminal 101 to resume measuring the radio quality of the frequencies determined to be unable to be estimated. In this case, the base station 111 may notify the terminal 101 of information specifying the frequencies at which measurement is to be resumed. The terminal 101 may recognize that measurement for the notified frequencies should be resumed. The base station 101 may resume measurement of some of the frequencies by further resetting the measurement configuration. For example, the base station 101 may notify the terminal 101 using ARFCN-ValueNR as information specifying the frequencies at which measurement is to be resumed in the measurement target. The base station 111 may also reset the SSB measurement configuration and MG configuration. The terminal 101 may perform the second notification using an RRC message such as UE Assistance Information, MAC CE, Uplink Control Information, etc.

[0057] As a metric for determining whether to terminate the prediction mode, the base station 111 may use the same evaluation value (metric) as that used when determining whether it is possible to estimate wireless quality for a period corresponding to another measurement period set by the measurement configuration using measurement values ​​for a portion of the measurement period set by the measurement configuration before the terminal 101 starts the prediction mode. For example, while the prediction mode is being executed, the terminal 101 performs measurement and prediction in a measurement period to be used for determining whether to terminate the prediction mode, and reports the measurement value and the estimated value to the base station 111. If the difference between the reported measurement value and the estimated value exceeds a predetermined threshold, the base station 111 may determine that it is no longer possible to estimate wireless quality for the notified predetermined period using the measurement value for the set measurement period. Note that the method by which the base station 111 determines whether to terminate the prediction mode is not limited to this. For example, the base station 111 may determine whether or not to terminate the prediction mode using an evaluation value (metric) similar to that used to determine whether it is possible to estimate the wireless quality for a period corresponding to another measurement period set by the measurement setting using measurements for a portion of the measurement period set by the measurement setting before the terminal 101 starts the prediction mode.

[0058] Furthermore, the base station 111 may terminate the prediction mode upon detecting that a value indicating the distribution of wireless quality measurement values ​​over a certain period of time during operation in the prediction mode has become different from the value indicating the distribution of wireless quality measurement values ​​when the prediction mode was started. The estimation formula or inference model used by the terminal 101 to estimate the wireless quality of neighboring cells is generated based on measurements acquired before the prediction mode was started. Therefore, if the environment around the terminal 101 changes over time, the estimation using the estimation formula or inference model may differ from the actual wireless quality. In this case, the base station 111 may detect a change in the environment by comparing the distribution of measurement values ​​during operation in the prediction mode with the distribution of measurement values ​​used when the estimation formula or inference model was generated. For example, the base station 111 may periodically compare the difference between an evaluation value calculated from the distribution of measurement values ​​acquired when the prediction mode was started and an evaluation value calculated from the distribution of measurement values ​​acquired during the prediction mode, and may determine to terminate the prediction mode if the difference exceeds a predetermined threshold. The value indicating the distribution of wireless quality may be, for example, the average, median, or variance of the received power measured over a certain period of time. A plurality of these may be used as evaluation values ​​for the determination.

[0059] In this way, even while the terminal 101 is executing the prediction mode, the base station 111 continues to use specified metrics to determine whether it is possible to estimate the wireless quality for the specified period notified using the measurement values ​​for the set measurement period, and terminates the prediction mode based on the determination that estimation is not possible.This makes it possible to reduce part of the measurement period in situations where estimation is possible and use the period corresponding to the reduced measurement period for other purposes, and to measure each measurement period as usual in situations where estimation is not possible, thereby accurately determining the wireless quality.

[0060] (First Modification) In the above description, an example was described in which the base station 111 acquires measured values ​​and estimated values ​​of wireless quality from the terminal 101 as information related to wireless quality, and determines whether or not it is possible to estimate wireless quality for periods corresponding to other measurement periods set by the measurement configuration using measured values ​​acquired during a portion of the measurement period set by the measurement configuration, using the acquired measured values ​​and estimated values, thereby determining whether or not it is possible to execute the prediction mode. In this modified example, an example will be described in which the terminal 101 determines whether or not it is possible to estimate wireless quality for periods corresponding to other measurement periods set by the measurement configuration using measured values ​​acquired during a portion of the measurement period set by the measurement configuration, using estimated values ​​of wireless quality for periods corresponding to other measurement periods set by the measurement configuration, using measured values ​​acquired during a portion of the measurement period set by the measurement configuration. In this example, the base station 111 receives a determination result from the terminal 101 as information related to wireless quality, and determines whether or not it is possible to execute the prediction mode based on the notified determination result.

[0061] FIG. 12 shows an example of an operation performed by the base station 111 when notifying the terminal 101 of an instruction to execute the prediction mode in this example. This operation may be performed based on the notification from the base station 111 to the terminal 101 indicating that use of the prediction mode is permitted in S404 of FIG. 4. Note that the same reference numerals are assigned to operations in FIG. 12 that are similar to those in FIG. 5, and descriptions thereof will be omitted. First, upon receiving a notification indicating that use of the prediction mode is permitted from the base station 111, the terminal 101 measures wireless quality in each measurement period set by the measurement configuration. Furthermore, the terminal 101 estimates wireless quality for periods corresponding to other measurement periods set by the measurement configuration using wireless quality measurement values ​​acquired in part of the measurement period set by the measurement configuration. Then, the terminal 101 calculates metrics using the acquired measurement values ​​and estimated values ​​(S1201). The metric calculation in the terminal 101 may be performed using a method similar to the metric calculation executed by the base station 111 in S501. Based on the calculated metric, the terminal 101 determines whether it is possible to estimate the received power in periods corresponding to the other measurement periods set by the measurement configuration using the measurement values ​​acquired in a part of the measurement period set by the measurement configuration. The terminal 101 notifies the base station 111 of the determination result as information on wireless quality. When notifying that it is possible to estimate the received power in periods corresponding to the other measurement periods set by the measurement configuration using the measurement values ​​acquired in a part of the measurement period set by the measurement configuration, the terminal 101 may notify the base station 111 of information specifying measurement periods that can be reduced. This allows the base station 111 to generate a measurement configuration to be used by the terminal 101 in the prediction mode.

[0062] For example, the terminal 101 may notify the base station 111 of information indicating the proportion of measurement periods in which wireless quality can be determined by estimation among the measurement periods set by the measurement configuration. If the base station 111 and the terminal 101 share information indicating the proportion of measurement periods in which wireless quality can be determined by estimation and the measurement periods to be maintained during reconfiguration in association with each other, the base station 111 may reconfigure the measurement configuration based on the information indicating these proportions. For example, if the terminal 101 can estimate the wireless quality of the periods corresponding to the other nine measurement periods by measuring one of the measurement periods set by the measurement configuration, the terminal 101 may notify the base station of information indicating that the proportion of measurement periods to be maintained during reconfiguration is 10% or that the proportion of measurement periods that can be estimated is 90%. Furthermore, the terminal 101 may notify the base station 111 of information specifying the identifier of a frame corresponding to the measurement period to be maintained during reconfiguration or the identifier of a frame corresponding to the measurement period that can be estimated. In this case, the terminal 101 may notify the base station of information specifying the SFN for which measurements will be performed or the SFN for which measurements will not be performed. SFN is an abbreviation for System Frame Number. For example, the terminal 101 may indicate the SFN by a combination of a divisor and a remainder in a modulo operation. For example, if the terminal 101 can estimate the radio quality for periods corresponding to nine other measurement periods based on measurements in one of the configured measurement periods, the terminal 101 may notify the base station 111 of a combination of 10 as the divisor and N (N is an integer from 0 to 9) as the remainder. The base station 111 may identify a frame whose SFN matches the notified divisor and remainder as the period in which the measurement will be performed. For example, if the remainder is 0, the base station 111 may recognize that the measurement will be performed in a measurement period included in a frame corresponding to an SFN for which the remainder when the SFN is divided by 10 is 0. The terminal 101 may also provide the base station 111 with the measurement configuration to be reconfigured or the estimated configuration. In this case, the terminal 101 may use the extended measurement configuration that the base station 111 uses when reconfiguring the measurement configuration, as described above. For example, the terminal 101 may notify the base station 111 of information specifying the measurement periods to be maintained or the measurement periods that can be estimated in the reconfiguration using a bitmap representation.

[0063] The base station 111 determines whether to cause the terminal 101 to execute the prediction mode based on information on the wireless quality notified by the terminal 101 (S502). Furthermore, if the base station 111 determines to cause the terminal 101 to execute the prediction mode, it may issue a first notification indicating an instruction to execute the prediction mode. At this time, the base station 111 may issue a notification to reset the measurement configuration and perform an estimation configuration based on information specifying a measurement period that can be reduced notified by the terminal 101. The terminal 101 operates in the prediction mode based on the first notification from the base station 111 and the measurement configuration and estimation configuration (S503).

[0064] In this way, by determining whether or not it is possible to estimate the received power in a period corresponding to another measurement period set by the measurement setting in the terminal 101 using the measurement value acquired in a part of the measurement period set by the measurement setting, the base station 111 does not need to calculate the metric or determine whether or not estimation is possible, thereby reducing the processing load on the base station 111. Furthermore, if the terminal 101 notifies the base station 111 when it is determined that the terminal 101 is in a state where estimation is possible, the amount of communication from the terminal 101 to the base station 111 can be reduced.

[0065] Alternatively, the terminal 101 may calculate an evaluation value of the metric, and the base station may use this evaluation value to determine whether it is possible to estimate the received power in a period corresponding to another measurement period set by the measurement configuration using measurements acquired in a part of the measurement period set by the measurement configuration. In this case, the base station can use a common determination criterion to determine whether each terminal should execute the prediction mode. Furthermore, when it is necessary to dynamically change the determination criterion, it is not necessary to provide the determination criterion to each terminal each time.

[0066] (Second Modification) In this modification, an example will be described in which the terminal 101 determines whether it is possible to estimate wireless quality for periods corresponding to other measurement periods set by the measurement configuration using measurement values ​​acquired during a portion of the measurement period set by the measurement configuration and estimated values ​​of wireless quality for periods corresponding to other measurement periods set by the measurement configuration, and further determines whether to execute the prediction mode. That is, based on the determination to execute the prediction mode, the terminal 101 requests permission to execute the prediction mode from the base station 111. The base station 111 receives the request from the terminal 101 as information regarding wireless quality and instructs the execution of the prediction mode based on the request.

[0067] FIG. 13 illustrates an example of an operation performed by the base station 111 when notifying the terminal 101 of an instruction to execute the prediction mode in this example. This operation may be performed based on the notification from the base station 111 to the terminal 101 indicating that use of the prediction mode is permitted in S404 of FIG. 4. Note that the same reference numerals are assigned to operations in FIG. 13 that are similar to those in FIG. 5 or 12, and descriptions thereof will be omitted. First, upon receiving a notification indicating that use of the prediction mode is permitted from the base station 111, the terminal 101 measures wireless quality in each measurement period set by the measurement configuration. Furthermore, the terminal 101 estimates wireless quality for periods corresponding to other measurement periods set by the measurement configuration using wireless quality measurement values ​​acquired in part of the set measurement period. Then, the terminal 101 calculates metrics using the acquired measurement values ​​and estimated values ​​(S1201). The metric calculation in the terminal 101 may be performed using a method similar to the metric calculation performed by the base station 111 in S501. The terminal 101 determines, based on the calculated metric, whether it is possible to estimate the received power in a period corresponding to another measurement period set by the measurement configuration using the measurement values ​​acquired in a part of the measurement period set by the measurement configuration. When the terminal 101 determines that it is possible to estimate the received power in a period corresponding to another measurement period set by the measurement configuration using the measurement values ​​acquired in a part of the measurement period set by the measurement configuration, the terminal 101 determines whether to execute a prediction mode (S1301).

[0068] For example, the terminal 101 may determine to execute the prediction mode based on determining that it is possible to estimate the received power for a period corresponding to another measurement period set by the measurement configuration using measurements acquired during a portion of the measurement period set by the measurement configuration. The terminal 101 may also make this determination based on the traffic conditions in the communication between the terminal 101 and the base station 111. In this case, the terminal 101 may determine to execute the prediction mode based on the amount of traffic in the communication between the terminal 101 and the base station 111 exceeding a predetermined threshold. The terminal 101 may also make this determination based on the battery conditions in the terminal 101. For example, the terminal 101 may determine not to start operation in the prediction mode if the remaining battery power is below a threshold. This makes it possible to reduce battery consumption when the power consumption required for determining wireless quality by estimation is large, thereby extending the operating time of the terminal 101.

[0069] When the terminal 101 determines to execute the prediction mode, it notifies the base station 111 of a request to permit execution of the prediction mode as information regarding wireless quality (S405). As in the first modification, the terminal 101 may also notify information specifying a measurement period that can be reduced. Based on the request from the terminal 101, the base station 111 sends a first notification indicating an instruction to execute the prediction mode (S406). At this time, the base station 111 may send a notification to reset the measurement configuration and perform an estimation configuration based on the information specifying the measurement period that can be reduced notified from the terminal 101. The terminal 101 operates in the prediction mode based on the first notification from the base station 111, the measurement configuration, and the estimation configuration (S503).

[0070] (Third Modification) The base station 111 may share with the terminal 101 in advance a first measurement configuration for when the prediction mode is not used and a second measurement configuration (including an estimation configuration) for when the prediction mode is used. Furthermore, when multiple estimation methods can be selected in the prediction mode, measurement configurations associated with the respective estimation methods may be shared. In this case, for example, upon receiving a notification from the base station 111 indicating that use of the prediction mode is permitted, the terminal 101 executes an operation for determining whether or not it is possible to estimate wireless quality for a period corresponding to another measurement period set by the measurement configuration using measurement values ​​acquired in a part of the measurement period set by the measurement configuration, using the first measurement configuration. The base station 111 determines whether or not to execute the prediction mode based on information on wireless quality notified by the terminal 101. If the base station 111 determines to execute the prediction mode in the terminal 101, it transmits a first notification indicating an instruction to execute the prediction mode. The first notification may include information identifying the estimation method to be used in the prediction mode. When the second measurement configuration associated with the estimation method to be used in the prediction mode is shared between the base station 111 and the terminal 101, the terminal 101 can reset the measurement configuration based on the identified estimation method to be used and perform the estimation configuration. In this way, the first measurement configuration for when the prediction mode is not used and the second measurement configuration for when the prediction mode is used are shared in advance between the base station 111 and the terminal 101, so that the base station 111 can reduce the amount of information to be notified to the terminal 101 in the first notification.

[0071] In addition, when one or more inference models to be used in the prediction mode are predetermined, the base station 111 may determine whether to execute the prediction mode based on whether the distribution of measurement values ​​acquired during the measurement period set by the measurement settings satisfies the condition for the distribution of measurement values ​​for which the predetermined inference model can be used. For example, if the distribution of the training data used to generate the inference model is similar to the distribution of measurement values ​​acquired during the measurement period set by the measurement settings, it is highly likely that the inference model can be used to estimate wireless quality. Therefore, when the difference between the value indicating the distribution characteristic associated with each inference model and the value indicating the distribution characteristic calculated from the measurement values ​​satisfies a predetermined condition (e.g., smaller than a predetermined threshold), the base station 111 may determine to execute the prediction mode using the inference model that satisfies the condition.

[0072] (Circuit configuration) An example of the configuration of the terminal 101 and base station 110 described above will be described. FIG. 14 is a diagram showing the hardware configuration of the terminal 101 and base station 110. In one example, the terminal 101 and base station 110 are configured to include a processor 1401, a ROM 1402, a RAM 1403, a storage device 1404, and a communication circuit 1405. The processor 1401 is a computer configured to include one or more processing circuits, such as a general-purpose CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit). The processor 1401 reads and executes programs stored in the ROM 1402 or the storage device 1404, thereby performing overall processing of the device and each of the above-mentioned processes. The ROM 1402 is a read-only memory that stores programs related to processing executed by the terminal 101 and base station 110, various parameters, and other information. The RAM 1403 functions as a workspace when the processor 1401 executes a program, and is a random access memory that stores temporary information. The storage device 1404 is, for example, a removable external storage device. The communication circuit 1405 is configured to include, for example, circuits for wired communication or wireless communication between the terminal 101 and the base station 110. For example, the terminal 101 and the base station 110 can communicate with each other using the communication circuit 1405 for LTE or 5G.

[0073] (Functional configuration) Fig. 15(A) is a diagram showing an example of the functional configuration of the base station 110. The base station 110 is configured to include, as its functions, a measurement setting unit 1501, an information communication unit 1502, a prediction mode execution determination unit 1503, and a prediction mode execution instruction unit 1504, for example. Fig. 15(A) shows the functional configuration of the base station 110 of this embodiment, and, for example, the general configuration of the base station 110 is omitted. Note that these functional units can be realized, for example, by the processor 1401 executing a program stored in the ROM 1402 or the storage device 1404 and controlling the communication circuit 1405 as necessary. However, the present invention is not limited to this, and for example, dedicated hardware for realizing each function may be provided.

[0074] The measurement setting unit 1501 performs settings for the terminal 101 to perform measurements. For example, the measurement setting unit 1501 acquires information specifying the transmission timing, frequency, etc. of SSB signals from other base stations, and performs measurement settings for the terminal 101 based on the information. Furthermore, the measurement setting unit 1501 resets the measurement settings or performs estimation settings when the terminal 101 executes a prediction mode. The measurement settings set by the measurement setting unit 1501 are notified to the terminal 101 via the communication circuit 1405. The information communication unit 1502 exchanges information with the terminal 101. For example, the information communication unit 1502 may receive a notification of whether the terminal 101 has a prediction function, a notification of information related to wireless quality, a report of the identified wireless quality, etc. Furthermore, the information communication unit 1502 may notify the terminal 101 that use of the prediction mode is permitted. Note that the information communication unit 1502 may share estimation methods, metric calculation methods, etc. with the terminal 101. The prediction mode execution determination unit 1503 determines whether to cause the terminal 101 to execute the prediction mode. For example, when the prediction mode execution determination unit 1503 acquires measured values ​​or estimated values ​​of wireless quality from the terminal 101, it may calculate metrics based on these measured values ​​or estimated values ​​and determine whether to cause the terminal 101 to execute the prediction mode based on whether a predetermined condition is satisfied. Note that when the prediction mode execution determination unit 1503 determines that it is possible to estimate wireless quality for a period corresponding to another measurement period set by the measurement setting using measured values ​​acquired in a part of the measurement period set by the measurement setting, determines that the prediction mode should be executed, or receives a request for permission to execute the prediction mode, it may determine whether to cause the terminal 101 to execute the prediction mode based on this information. Furthermore, the prediction mode execution determination unit 1503 determines whether to end the prediction mode of the terminal 101. The prediction mode execution instruction unit 1504 notifies the terminal 101 of a first instruction indicating that the prediction mode should be executed. For example, the prediction mode execution instructing unit 1504 may notify the terminal 101 of a first instruction based on the determination of the prediction mode execution determining unit 1503. Furthermore, the prediction mode execution instructing unit 1504 may notify the terminal 101 of a second instruction indicating that the prediction mode should be ended.For example, the prediction mode execution instruction unit 1504 can notify the terminal 101 of a second instruction based on the determination of the prediction mode execution determination unit 1503.

[0075] FIG. 15B is a diagram illustrating an example of the functional configuration of the terminal 101. The terminal 101 includes, as its functions, a setting acquisition unit 1511, a wireless quality identification unit 1512, an information provision unit 1513, a prediction mode instruction reception unit 1514, a prediction mode execution determination unit 1515, and an information communication unit 1516, for example. FIG. 15B illustrates the functional configuration of the terminal 101 of this embodiment, and, for example, omits the general configuration of the terminal 101. Note that these functional units can be realized, for example, by the processor 1401 executing a program stored in the ROM 1402 or the storage device 1404 and controlling the communication circuit 1405 as necessary. However, the present invention is not limited to this, and for example, dedicated hardware for realizing each function may be provided.

[0076] The setting acquisition unit 1511 acquires measurement settings from the base station 110. For example, the setting acquisition unit 1511 acquires an RRC message including MeasConfig from the base station 110 and sets the MG set for measurement, the frequency of the measurement target, the timing and period for measurement, etc. Furthermore, the setting acquisition unit 1511 may acquire reset measurement settings and estimation settings when executing the prediction mode. In this case, the setting acquisition unit 1511 may reset the target to be measured and the MG using the acquired measurement settings. Furthermore, the setting acquisition unit 1511 may set the target to be estimated using the acquired estimation settings. The wireless quality identification unit 1512 identifies the wireless quality of a neighboring cell. For example, the wireless quality identification unit 1512 measures and identifies the wireless quality of a frequency specified by the base station 110 based on information such as the MG set by the setting acquisition unit 1511, the frequency of the measurement target, the timing and period for measurement, etc. Furthermore, in the prediction mode, the wireless quality identification unit 1512 may estimate the wireless quality during the period to be estimated using the wireless quality measured during the set measurement period. The information providing unit 1513 provides information to the base station 110. For example, the information providing unit 1513 notifies the base station 110 that its own device has a prediction function, notifies the base station 110 of information related to wireless quality, and reports the identified wireless quality. When notifying the base station 110 that its own device has a prediction function, the information providing unit 1513 may also notify the base station 110 of an estimation method supported by its own device, a metric calculation method, and the like. The prediction mode instruction receiving unit 1514 receives a first notification from the base station 110 instructing the base station 110 to execute the prediction mode. Upon receiving the first notification, the prediction mode instruction receiving unit 1514 notifies the wireless quality identifying unit 1512 to execute the prediction mode. Note that, if the received first notification includes information for resetting the measurement setting or information on estimation settings for making estimation, the prediction mode instruction receiving unit 1514 notifies the setting acquisition unit 1511 of that information. Furthermore, the prediction mode instruction receiving unit 1514 may receive a second notification instructing the base station 110 to end the prediction mode. When the prediction mode instruction receiving unit 1514 receives the second notification, it notifies the wireless quality specifying unit 1512 to end the prediction mode.The prediction mode execution determination unit 1515 may calculate a metric, determine whether or not to execute a prediction mode, and the like, based on the measured or estimated value of the wireless quality identified by the wireless quality identification unit 1512. The evaluation value of the metric calculated by the prediction mode execution determination unit 1515, the determination of whether or not to execute a prediction mode, a request for permission to execute a prediction mode, and the like may be notified to the base station 110 as information related to wireless quality. The information communication unit 1516 communicates with the base station 110. For example, the information communication unit 1516 communicates with the base station 110 based on a schedule notified by the base station 110.

[0077] As described above, according to this embodiment, the base station 110 uses measurement results from a portion of the measurement period set by the measurement configuration to determine whether to estimate the radio quality of a frequency during a predetermined period corresponding to another measurement period set by the measurement configuration, and notifies the terminal 101 of information indicating the resetting of the measurement period during which measurement should be performed and the period during which estimation should be performed based on the determination result. Furthermore, the terminal 101 measures the radio quality of the frequency during the reset measurement period and estimates the radio quality for the predetermined period using the measurement results, based on the information indicating the resetting of the measurement period during which measurement should be performed and the predetermined period during which estimation should be performed, notified by the base station 110. With this configuration, the base station 110 can reset the measurement period during which radio quality measurements should be performed and set the target for which radio quality estimation should be performed, based on the fact that the base station 110 can estimate the radio quality of a frequency during a period corresponding to another measurement period set by the measurement configuration using the measurement results from a portion of the measurement period set by the measurement configuration. This allows resources for the period during which measurement is omitted to be used for other purposes. In this way, the period used by the terminal for measurement when identifying the radio quality of a neighboring cell can be reduced, thereby improving communication efficiency. This will enable us to contribute to Goal 9 of the United Nations' Sustainable Development Goals (SDGs), which is to "Build resilient infrastructure, promote sustainable industrialization and foster innovation."

[0078] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the invention. [Explanation of symbols]

[0079] 101: terminal, 111: base station, 112: base station, 113: base station

Claims

1. A base station that communicates with a terminal device based on a cellular communication standard of the Third Generation Partnership Project (3GPP), providing means for providing the terminal device with setting information including a measurement period for the terminal device to measure radio quality of a frequency; an acquisition means for acquiring, from the terminal device, predetermined information relating to the radio quality of the frequency measured during the measurement period set by the setting information; a determination means for determining, based on the predetermined information, whether to estimate the radio quality of the frequency in a period corresponding to the other measurement period set by the setting information, using a measurement result in a part of the measurement period set by the setting information; and and instruction means for instructing the terminal device to perform the estimation, the instruction including reset information for resetting the measurement period based on the result of the determination and information for specifying a predetermined period for which the wireless quality of the frequency should be estimated. A base station characterized by:

2. The predetermined information includes, for at least one measurement period out of the measurement periods set based on the setting information, information indicating an estimated value of radio quality of the frequency estimated based on measured values ​​of radio quality of the frequency in other measurement periods out of the measurement periods, and information indicating the measured value of radio quality of the frequency in the at least one measurement period out of the measurement periods.

2. The base station according to claim 1 .

3. The predetermined information includes information indicating that it is possible to estimate the radio quality of the frequency in a period corresponding to another measurement period using the measured value of the frequency in a portion of the measurement period set based on the setting information.

2. The base station according to claim 1 .

4. The reset information includes information indicating a first period between a first measurement period and a second measurement period included in the measurement period reset by the reset information, and a second period between the second measurement period and a third measurement period, the second measurement period being adjacent to the first measurement period and the third measurement period, and the second period being different from the first period.

2. The base station according to claim 1 .

5. The predetermined period includes a period corresponding to a measurement period other than the measurement period reset by the reset information, among the measurement periods set by the setting information.

2. The base station according to claim 1 .

6. The measurement period is at least one of a Measurement Gap (MG) or a Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) Block Measurement Timing Configuration (SMTC) window.

2. The base station according to claim 1 .

7. A terminal device that communicates with a base station based on a cellular communication standard of the Third Generation Partnership Project (3GPP), an acquisition means for acquiring, from the base station, setting information including a measurement period for the terminal device to measure the radio quality of a frequency; a determination unit that measures a wireless quality of the frequency during a measurement period set based on the setting information and determines the wireless quality; a providing means for providing the base station with predetermined information to be used when the base station determines that it should estimate the radio quality of the frequency in a period corresponding to another measurement period set based on the setting information, using a measurement result in a part of the measurement period set based on the setting information; a receiving means for receiving, from the base station, an instruction indicating that the estimation should be performed, the instruction including reset information indicating the measurement period that is reset based on the determination and information specifying a predetermined period during which the radio quality of the frequency should be estimated; When the instruction is received, the specifying means specifies the wireless quality of the frequency by measuring the wireless quality of the frequency during the reset measurement period and estimating the wireless quality of the frequency during the predetermined period specified by the instruction using the wireless quality of the frequency acquired by the measurement. A terminal device characterized by:

8. The providing means provides the predetermined information including, for at least one measurement period out of the measurement periods set based on the setting information, information indicating an estimated value of wireless quality of the frequency estimated based on measured values ​​of wireless quality of the frequency in other measurement periods out of the measurement periods, and information indicating the measured value of wireless quality of the frequency in the at least one measurement period out of the measurement periods.

8. The terminal device according to claim 7,

9. The method further includes a determination unit that determines whether it is possible to estimate the radio quality of the frequency in a period corresponding to another measurement period using a measurement value in a portion of the measurement period that is set based on the setting information, The providing means provides the predetermined information including information indicating the result of the determination.

8. The terminal device according to claim 7,

10. The reset information includes information indicating a first period between a first measurement period and a second measurement period included in the measurement period set by the reset information, and a second period between the second measurement period and a third measurement period, the second measurement period being adjacent to the first measurement period and the third measurement period, and the second period being different from the first period.

8. The terminal device according to claim 7,

11. The predetermined period includes a period corresponding to a measurement period other than the measurement period reset by the reset information, among the measurement periods set by the setting information.

8. The terminal device according to claim 7,

12. The measurement period is at least one of a Measurement Gap (MG) or a Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) Block Measurement Timing Configuration (SMTC) window.

8. The terminal device according to claim 7,

13. 1. A control method executed by a base station communicating with a terminal device based on a cellular communication standard of a Third Generation Partnership Project (3GPP), comprising: a providing step of providing the terminal device with setting information including a setting of a measurement period for the terminal device to measure the radio quality of a frequency; an acquisition step of acquiring, from the terminal device, predetermined information regarding the radio quality of the frequency measured during the measurement period set by the setting information; a determination step of determining, based on the predetermined information, whether to estimate the radio quality of the frequency in a period corresponding to the other measurement period set by the setting information, using a measurement result in a part of the measurement period set by the setting information; and an instruction step of issuing an instruction to the terminal device indicating that the estimation should be performed, the instruction including reset information for resetting the measurement period and information for specifying a predetermined period for which the wireless quality of the frequency should be estimated based on the result of the determination. A control method comprising:

14. 1. A control method executed by a terminal device that communicates with a base station based on a cellular communication standard of a Third Generation Partnership Project (3GPP), comprising: an acquisition step of acquiring, from the base station, setting information including a measurement period for the terminal device to measure the radio quality of the frequency; a determination step of measuring a wireless quality of the frequency during a measurement period set based on the setting information and determining the wireless quality; a providing step of providing the base station with predetermined information to be used when the base station determines that it should estimate the radio quality of the frequency in a period corresponding to another measurement period set based on the setting information, using a measurement result in a part of the measurement period set based on the setting information; a receiving step of receiving, from the base station, an instruction indicating that the estimation should be performed, the instruction including reset information indicating the measurement period that is reset based on the determination and information specifying a predetermined period during which the radio quality of the frequency should be estimated; When the instruction is received, the specifying step specifies the wireless quality of the frequency by measuring the wireless quality of the frequency during the reset measurement period and estimating the wireless quality of the frequency during the predetermined period specified by the instruction using the wireless quality of the frequency acquired by the measurement. A control method comprising:

15. A program for causing a computer to function as each of the means possessed by the base station according to claim 1.

16. A program for causing a computer to function as each of the means included in the terminal device according to claim 7.

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