Terminal device, base station, control method, and program for efficiently measuring peripheral cells

Abstract

This terminal device having a communication means for communicating with a base station on the basis of the cellular communication standard of the third generation partnership project (3GPP): acquires, from the base station, setting information for setting measurement gaps (MGs) for measuring the radio quality of a signal transmitted at a frequency other than a frequency used for communication with the base station; performs measurement of the radio quality of the frequency in at least one first MG set according to the setting information; sends, to the base station on the basis of the fact that it is possible to estimate the radio quality of the frequency in a period corresponding to a second MG set according to the setting information by using the measurement result in the first MG, a first notification indicating that measurement based on the setting information in the period corresponding to the second MG is not performed; and after the first notification has been sent, identifies the radio quality of the frequency in the period corresponding to the second MG through estimation without performing measurement based on the setting information in the period corresponding to the second MG.

Description

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

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

[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 present in the vicinity of the terminal is identified. For example, a terminal connected to a base station such as a gNB (next generation Node B) or an eNB (evolved Node B) measures frequencies other than the frequency used for communication during a set Measurement Gap (MG) period to identify the wireless quality of other cells and report the identification result to the base station. Non-Patent Document 1 defines the definition of the MG set in the terminal.

[0003] 3GPP TS 38.331 “NR; Radio Resource Control (RRC) protocol specification”

[0004] During the above-mentioned MG period, the terminal performs measurements of other frequencies and is therefore unable to communicate with the serving cell to which the terminal is connected. Therefore, communication performance, such as throughput and transmission delay, is reduced by the time required for the 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.

[0005] A terminal device according to one aspect of the present invention is a terminal device having communication means for communicating with a base station based on the cellular communication standard of the Third Generation Partnership Project (3GPP), and includes: acquisition means for acquiring from the base station configuration information for setting Measurement GAPs (MGs) for measuring wireless quality of signals transmitted at frequencies other than a frequency used for communication with the base station; measurement means for measuring wireless quality of the frequency in at least one first MG set by the configuration information; notification means for sending to the base station a first notification indicating that measurement based on the configuration information will not be performed during a period corresponding to a second MG set by the configuration information, based on the fact that it is possible to estimate wireless quality of the frequency during a period corresponding to the second MG using a measurement result in the first MG; and identification means for, after sending the first notification, not performing measurement based on the configuration information during the period corresponding to the second MG, and identifying by estimation wireless quality of the frequency during the period corresponding to the second MG.

[0006] According to the present invention, in a mobile communication system, communication efficiency can be improved by efficiently identifying the radio quality of neighboring cells.

[0007] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals.

[0008] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments of the present invention, and together with the description, are used to explain the principles of the present invention. FIG. 1 is a diagram showing an example of the configuration of a mobile communication system. FIG. 2 is a diagram showing an example of the relationship between an SMTC and an MG. FIG. 3 is a diagram showing an example of the relationship between SSB measurement settings and an MG setting. FIG. 4 is a diagram showing an example of a sequence executed between a base station and a terminal. FIG. 5 is a diagram showing an example of a processing flow executed in a terminal when determining whether wireless quality can be estimated. FIG. 6 is a diagram showing an example of the relationship between an SSB signal and an MG. FIG. 7 is a diagram showing an example of the relationship between an SSB signal and an MG. FIG. 8 is a diagram showing an example of a measurement period and a non-measurement period using a representation similar to the MG setting. FIG. 9 is a diagram showing an example of a measurement period and a non-measurement period using a bitmap representation. FIG. 10 is a diagram showing an example of a sequence executed between a base station and a terminal when the terminal performs handover. FIG. 11 is a diagram showing an example of the hardware configuration of a base station and a terminal. FIG. 12 is a diagram showing an example of the functional configuration of a base station. FIG. 13 is a diagram showing an example of the functional configuration of a terminal.

[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 combined in any desired manner. Furthermore, the same reference numerals are used to designate identical or similar components, and redundant descriptions will be omitted.

[0010] (System Configuration) FIG. 1 shows an example 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), an evolved Node B (eNB), etc. 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. Furthermore, the base station 110 and the terminal 101 may communicate using radio signals in frequency bands such as the 700 MHz band, 800 MHz band, 900 MHz band, 1.5 GHz band, 1.7 GHz band, 2 GHz band, 2.5 GHz band, 3.4 GHz band, and 3.5 GHz band. Furthermore, the base station 110 and the terminal 101 may communicate using radio signals in the 2.6 GHz band, 4.9 GHz band, 26 GHz band, and 40 GHz band. For example, in FIG. 1 , it is assumed that the base station 111 and the terminal 101 communicate using a first frequency. It is also assumed that the base station 112 and the base station 113 can communicate with the terminal 101 using frequencies other than the first frequency, such as a second frequency and 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 stations 112 and 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. The cell 121 provided by the base station 111 that is communicating with the terminal 101 may be referred to as a serving cell in relation to the terminal 101. In FIG. 1 , the cells 122 and 123 formed by the base stations 112 and 113 other than the serving cells, respectively, may be referred to as neighboring cells in relation to the 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 can 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 can 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, can 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 determined 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 notify the terminal 101 of a measurement configuration (MeasConfig) for causing the terminal 101 to perform measurement, using an RRC Connection Reconfiguration message. 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 indicating a period during which data is not transmitted or received in order to perform measurement. During the period in which the MG is set, the terminal 101 may determine 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 the measurement configuration. For example, when 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. 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, when 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 reporting configuration can be used to notify the terminal 101 of the type of trigger for a measurement report, parameters used for the trigger, the reporting 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 setting 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. Meanwhile, the MGRP notified by the base station 111 may be selected from among 20 ms, 40 ms, 80 ms, and 160 ms. The terminal 101 may specify the start position of the MG (SFN and subframe of a radio frame) based on the MGRP and offset value (gapOffset) notified by the base station 111, for example, using the following formula:

[0017] SFN mod (MGRP / 10) = FLOOR (gapOffset / 10) Subframe = gapOffset mod 10 In the above formula, for example, if MGRP = 20 ms and gapOffset = 1, the SFNs of the radio frames in which MG starts are 0, 2, 4, 6, ..., and MG starts at Subframe = 1 in each SFN.

[0018] When the terminal 101 receives a measurement configuration from the base station 111, it measures the received power of neighboring cells according to 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 can use the received SSB signal to measure received power (which may also be referred to as Reference Signal Receive Power, RSRP), received quality (which may also be referred to as Reference Signal Receive Quality, RSRQ), etc. The terminal 101 can transmit a measurement report including the RSRP, RSRQ, etc. to the base station 111.

[0019] FIG. 2 shows the relationship between the SMTC and the MG set in the measurement target. As shown in FIG. 2, the MG can be set 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. Furthermore, each SSB signal can be transmitted using the same beam or different beams. Furthermore, the SSB signals can be transmitted independently at 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 periods of the two subframes in which these SSB signals are included, as the periods during which the SSB signals should be measured. The period during which the SSB signal should be measured may be referred to as the SMTC window. For example, the base station 112 may notify other base stations (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 period, an offset, and a period 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 the measurement 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 set.

[0020] FIG. 3 shows an example in which the MG and SSB measurement are periodically configured by the base station 111 through measurement configuration. The SSB measurement indicates the timing at which the SSB signal to be measured should be measured. The SSB signal 210 may be the 0th SSB signal 200 through the 3rd SSB signal 203 in FIG. 2. As shown in FIG. 3, the period 301 and duration 302 of the SSB measurement period (SMTC window) may be configured to include each SSB signal 210. Furthermore, the MGL 303 and MGRP 304 of the MG may be configured to include each SSB measurement period. Note that the SSB measurement period period 301 may be configured to include all of the SSB signals 210, or may not be configured to include all of the SSB signals 210.

[0021] As described above, the base station 111 sets an MG, a period during which data transmission and reception with the terminal 101 connected to the base station 111 is not performed, and causes the terminal 101 to measure the wireless quality of neighboring cells. In this case, the terminal 101 cannot transmit or receive data with the base station 111 during the MG period, which may result in a decrease in throughput and an increase in delay time during the MG period. In contrast, if wireless quality measurements in some MGs can be used to estimate wireless quality during a period corresponding to another MG, the terminal 101 may be able to omit some of the measurements. For example, the terminal 101 may be able to transmit and receive data with the base station 111 during the period corresponding to the omitted measurement period. However, no mechanism is provided for utilizing resources generated by omitting some of the measurements for other purposes. For example, when the terminal 101 can estimate the wireless quality of neighboring cells, no method is provided for notifying the base station 111 of an MG that is no longer being used for measurements, using the MG for another purpose, or changing the MG. Furthermore, no method is provided for setting the MG or SMTC to be used when the radio quality of a neighboring cell is identified by measurement and estimation.

[0022] In consideration of these circumstances, the terminal 101 in this embodiment measures the radio quality of a frequency in at least one first MG configured by the measurement configuration acquired from the base station 111, and determines whether it is possible to estimate the radio quality of the frequency in a period corresponding to a second MG using the measurement results. Then, based on whether it is possible to estimate the radio quality of the frequency, the terminal 101 sends a first notification to the base station 111 indicating that it will not perform measurements based on the measurement configuration in a period corresponding to the second MG. Furthermore, after sending the first notification, the terminal 101 estimates the radio quality of the frequency in a period corresponding to the second MG without performing measurements based on the configuration information in the period corresponding to the second MG. With this configuration, when it is possible to estimate the radio quality of a frequency in a period corresponding to the second MG among the MGs configured by the measurement configuration, the terminal 101 can utilize the second MG for another purpose without using it for measurements. For example, the terminal 101 can notify the base station 111 of information that enables it to identify the second MG. This allows the base station 111 to perform scheduling by assuming that resources for the period corresponding to the second MG can be used for communication with the terminal 101. Furthermore, after the terminal 101 has sent the first notification, if it becomes impossible to estimate the radio quality of the frequency for the period corresponding to the second MG, the terminal 101 can send a second notification to the base station 111 indicating that it will change or stop the estimation of the radio quality. This allows the second MG to be used for another purpose only when it is possible to estimate the radio quality, and when it is impossible to estimate the radio quality, it is possible to perform measurement and accurately identify the radio quality. Below, information exchanged between the terminal 101 and the base station 111 operating as described above and configuration examples of each device will be described.

[0023] (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 the terminal 101 uses measurement values ​​acquired in a portion of the MG configured by the measurement configuration to estimate wireless quality for a period corresponding to another MG will be described. In this embodiment, the function of the terminal 101 to estimate wireless quality for a period corresponding to another MG using measurement values ​​acquired in a portion of the MG will be referred to as a prediction function. Furthermore, the operation of the terminal 101 to estimate wireless quality for a period corresponding to another MG using measurement values ​​acquired in a portion of the MG will be referred to as a prediction mode. Furthermore, the MG corresponding to the period during which the terminal 101 measures wireless quality will be referred to as a first MG, and the MG corresponding to the period during which the terminal 101 determines wireless quality by estimation using the first MG will be referred to as a second MG. For example, when the terminal 101 is not executing the prediction mode, each of the MGs configured by the measurement configuration may be the first MG. Furthermore, when the terminal 101 is executing the prediction mode, the MG corresponding to the period in which measurements are performed may be the first MG, and the MG corresponding to the period in which measurements are not performed may be the second MG.

[0024] 4 shows an example of a sequence of messages exchanged between the base station 111 and the terminal 101. This sequence may be executed, for example, after the terminal 101 establishes a wireless connection and an RRC connection with the base station 111 using a random access procedure 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 addition, in a notification indicating that the terminal 101 has a prediction function, the terminal 101 may notify information indicating the estimation method supported by the terminal 101 and the calculation method of the evaluation value (metrics) for determining whether or not estimation is possible. For example, the terminal 101 may notify information indicating the estimation method supported by the terminal 101, such as the moving average method, exponential smoothing, regression analysis, and estimation methods using an AI model, which will be described later. Furthermore, in the case of an estimation method using an AI model, if the terminal 101 supports multiple types of AI models, the terminal 101 may notify information identifying the AI ​​model supported by the terminal 101. 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 another base station from measurements of a signal transmitted from one base station, and an AI model for estimating the wireless quality of a signal transmitted using another beam from measurements of a signal transmitted using one beam. Examples of prediction methods and calculation methods of metrics supported by the terminal 101 will be described later. 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 can notify the terminal 101 using an RRC Reconfiguration message.In addition, if the terminal 101 has a prediction function, the base station 111 may determine whether to allow 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 allow the terminal 101 to use the prediction mode based on the fact that the estimation method or metric 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 allow 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 allow 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 allow 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.

[0025] When the terminal 101 receives a notification from the base station 111 indicating that the use of the predictive mode is permitted, the terminal 101 determines whether it is possible to estimate the wireless quality for a period corresponding to another MG using measurements acquired in some of the MGs (S405). That is, the terminal 101 determines whether it is possible to estimate the wireless quality for a period corresponding to a second MG using measurements acquired in a first MG. On the other hand, if the terminal 101 does not receive a notification from the base station 111 indicating that the use of the predictive mode is permitted, the terminal 101 performs measurements in each of the MGs configured by the measurement configuration to determine the wireless quality. If the terminal 101 determines that it is possible to estimate the wireless quality for a period corresponding to a second MG using measurements acquired in the first MG, it operates using the predictive mode. For example, the terminal 101 performs measurements in the first MG to determine the received power of neighboring cells. Furthermore, the terminal 101 determines the received power for a period corresponding to the second MG by estimation using the received power of neighboring cells acquired through measurements in the first MG. Then, the terminal 101 reports each of the identified received powers to the base station 111 (S406). For example, the terminal 101 may report using a Measurement Report. Note that if the terminal 101 is unable to estimate the wireless quality for the period corresponding to the second MG using the measurement value of the first MG, it does not operate in the prediction mode. In this case, the terminal 101 performs measurements in each MG and identifies the received power of the neighboring cells. The terminal 101 then reports the received power in each identified MG to the base station 111. The terminal 101 may also perform handover, etc., based on each of the identified received powers.

[0026] (Method for Determining Whether Estimation is Possible) FIG. 5 shows an example of an operation performed by the terminal 101 when determining whether it is possible to estimate the wireless quality for a period corresponding to a second MG using measurements from a first MG and notifying the base station 111. This operation corresponds to S405 in FIG. 4. For example, the terminal 101 may output an estimated value of wireless quality for at least one of the MGs configured by the measurement configuration based on measurements from other MGs, and determine that estimation is possible based on the difference between the estimated value and the measurement from the at least one MG being smaller than a predetermined threshold. First, the terminal 101 measures the wireless quality of neighboring cells using at least one of the MGs configured by the measurement configuration, performs estimation using the acquired measurements, and calculates a metric (S501). For 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 terminal 101 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 measured at the second frequency. In FIG. 6 , SSB signals 601-605 each represent an SSB signal periodically transmitted by base station 112. MGs 611-615 represent subframes in the radio frame of the cell provided by base station 111, in which an MG for terminal 101 is set. In this manner, MGs 611-615 can be set so that terminal 101 can measure the received power of each SSB signal 601-605 at the timing when each SSB signal is transmitted. Terminal 101 measures the received power of SSB signals 601-605 at each of MGs 611-615. Terminal 101 also estimates the received power of SSB signals 603 and 604, for example, using the measured values ​​of SSB signals 601 and 602. Terminal 101 then uses the difference between the measured value and estimated value of SSB signal 603 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 the estimated value of the SSB signal 603 is less than or equal to a predetermined threshold, the terminal 101 can determine that it is possible to estimate the radio quality for the period corresponding to the second MG using the measured value of the first MG.Furthermore, if the difference between the measured value and the estimated value of SSB signal 603 is not equal to or less than a predetermined threshold, terminal 101 may determine that it is not possible to estimate the wireless quality for the period corresponding to the second MG using the measured value of the first MG. In this way, terminal 101 may determine whether it is possible to estimate the wireless quality for the period corresponding to the second MG using the measured value of the first MG, based on whether the difference between the estimated value of received power for the period corresponding to another MG, estimated using measured values ​​obtained using a part of the MG, and the measured value actually measured in that MG, is within a predetermined range.

[0027] The terminal 101 may make its determination using the measured and estimated values ​​of the SSB signal 604 in addition to the measured and estimated values ​​of the SSB signal 603. For example, the terminal 101 may determine that it is possible to estimate the wireless quality in the period corresponding to the second MG using the measured values ​​of the first MG based on the fact that both the difference between the measured and estimated values ​​of the SSB signal 603 and the difference between the measured and estimated values ​​of the SSB signal 604 are equal to or less than a predetermined threshold. That is, the terminal 101 may determine that it is possible to estimate the wireless quality in the period corresponding to the second MG using the measured values ​​of the first MG 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 terminal 101 may determine that it is possible to estimate the wireless quality in the period corresponding to the second MG using the measured values ​​of the first MG 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, a sum, a weighted sum, an average value, a weighted average value, a maximum value, etc., but is not limited to these. 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 powers 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 terminal 101 may calculate the evaluation value over a certain period of time and determine whether the calculated evaluation value satisfies a predetermined condition, thereby determining whether it is possible to estimate the wireless quality for the period corresponding to the second MG using the measured values ​​of the first MG. As an example, the terminal 101 may determine that it is possible to estimate the wireless quality for the period corresponding to the second MG using the measured values ​​of the first MG based on, for example, whether the average of the evaluation values ​​calculated over the certain period of time is equal to or less than a predetermined threshold, or whether a predetermined percentage of the evaluation values ​​calculated over the certain period of time is equal to or less than a predetermined threshold.

[0028] When there is a certain correlation between the radio quality of SSB signals transmitted at each of multiple frequencies, the terminal 101 can estimate the radio quality of SSB signals at one frequency using the measured value of the SSB signal at another frequency. For example, when the base station 112 configures cells using a second frequency and a third frequency, the terminal 101 determines whether it is possible to estimate the received power of SSB signals transmitted at the third frequency cell using a portion of the measured value of the received power of SSB signals transmitted at the second frequency cell, as will be described with reference to FIG. 7. In FIG. 7, SSB signals 701, 703, and 705 each represent an SSB signal periodically transmitted at the second frequency cell. Furthermore, SSB signals 702 and 704 each represent an SSB signal periodically transmitted at the third frequency cell. Furthermore, MGs 711 to 715 represent subframes in which MGs for the terminal 101 are set on the radio frame of the cell provided by the base station 111. In this case, terminal 101 may measure the received power of SSB signals 701, 703, and 705 transmitted in a cell using the second frequency in MGs 711, 713, and 715. Terminal 101 may also measure the received power of SSB signals 702 and 704 transmitted using the third frequency in MGs 712 and 714. Terminal 101 measures the received power of each of SSB signals 701 to 705 in each of MGs 711 to 715, for example. Terminal 101 also estimates the received power of SSB signals 702 and 704 using the measured values ​​of SSB signals 701 and 703. Terminal 101 then uses the difference between the measured and estimated values ​​of SSB signal 703 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 the estimated value of the SSB signal 702 is equal to or less than a predetermined threshold, the terminal 101 may determine that it is possible to estimate the wireless quality in the period corresponding to the MG corresponding to the third frequency using the measured value acquired in the MG corresponding to the second frequency. Also, if the difference between the measured value and the estimated value of the SSB signal 702 is not equal to or less than the predetermined threshold, the terminal 101 may determine that it is not possible to estimate the wireless quality in the period corresponding to the MG corresponding to the third frequency using the measured value acquired in the MG corresponding to the second frequency.The method by which terminal 101 determines whether it is possible to estimate the wireless quality for a period corresponding to an MG corresponding to a third frequency using measurements acquired in an MG corresponding to a second frequency is not limited to this, and any method corresponding to the method described in the example shown in Figure 6 can be similarly applied.

[0029] The terminal 101 may determine that it is possible to estimate the wireless quality for a period corresponding to a second MG using the measurements of a first MG based on the difference between a measurement value for at least one MG configured by the measurement configuration and a measurement value for another MG configured within a predetermined period from the first MG being 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 the environmental fluctuations around the terminal 101 are small. The terminal 101 may detect such a situation of the terminal 101 by evaluating the difference between the measurements acquired within a predetermined period. For example, in FIG. 6 , the terminal 101 may determine that it is possible to estimate the wireless quality for a period corresponding to a second MG using the measurements of a first MG based on the difference between the measurement value of SSB signal 601 and the measurement values ​​of SSB signals 602, 603, 604, or 605 being smaller than a predetermined threshold. Furthermore, based on the fact that the difference between the measurement values ​​of SSB signals 701, 703, and 705 and the measurement values ​​of SSB signals 702 and 704 in FIG. 7 is smaller than a predetermined threshold, terminal 101 may determine that it is possible to estimate the wireless quality at the third frequency using the measurement values ​​acquired at the second frequency.

[0030] In addition, when the terminal 101 supports multiple estimation methods (including multiple inference models) and metric calculation methods, it may evaluate each of them in parallel to determine whether it is possible to estimate the wireless quality for a period corresponding to the second MG using the measurement value of the first MG. If it is determined that estimation is possible using multiple estimation methods, an estimation method with a relatively high evaluation value of the calculated metric (for example, a small difference between the measurement value and the estimated value) may be selected. In addition, the estimation formula or inference model may be provided to the terminal 101 from the base station 111. Furthermore, information regarding a threshold value for determining the metric may be broadcast or individually notified to the terminal 101 from the base station 111, or may be set in the terminal 101.

[0031] (Operation when Executing Prediction Mode) Returning to FIG. 5 , the explanation continues. When the terminal 101 determines that it is possible to estimate the wireless quality for a period corresponding to a second MG using the measurement values ​​of a first MG, it may start operating in the prediction mode. For example, the terminal 101 determines the received power by estimation without performing measurements for the MGs for which it was determined in S501 that wireless quality estimation is possible. For example, the terminal 101 may determine that it is possible to estimate the wireless quality for periods corresponding to MGs 613 and 614 in FIG. 6 and MGs 712 and 714 in FIG. 7. In other words, these may be second MGs. By not performing measurements for these MGs, the terminal 101 becomes able to communicate with the base station 111 using resources for the periods corresponding to these MGs. Note that when the terminal 101 determines that it is possible to estimate the wireless quality for a period corresponding to a second MG using the measurement values ​​of the first MG, it may determine whether to start operating in the prediction mode based on whether a predetermined condition is satisfied. For example, the terminal 101 may determine whether to start operation in the prediction mode based on the remaining battery power of the terminal 101. As an example, the terminal 101 may determine not to start operation in the prediction mode when 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 operation time of the terminal 101.

[0032] The terminal 101 transmits a first notification to the base station indicating that it has started operating in the prediction mode (S503). The first notification may be a notification indicating that measurements will not be performed in some MGs, or a notification indicating that it is possible to estimate wireless quality for a period corresponding to a second MG using measurements from a first MG. When an estimation method using an AI model is used in the prediction mode, the first notification may include a notification of activating the AI ​​model (model activation). In addition, the terminal 101 may notify the base station 111 in the first notification of information identifying an MG (first MG) that will perform measurements, or information identifying an MG (second MG) that will not perform measurements. For example, the terminal 101 may notify information indicating the proportion of the first MG or the second MG among the MGs configured by the measurement configuration. If information indicating these ratios and the location of the first MG or the second MG are associated and shared between the base station 111 and the terminal 101, the base station 111 may identify the second MG based on the information indicating these ratios. For example, if the terminal 101 can estimate the received power for a period corresponding to nine other MGs (second MGs) by measuring one MG (first MG) among the MGs configured by the measurement configuration, the terminal 101 may notify the base station of information indicating that the ratio of MGs performing measurements is 10% or information indicating that the ratio of MGs not performing measurements is 90%. Furthermore, in the first notification, the terminal 101 may notify the base station 111 of information specifying the identifier of a frame corresponding to the MG (first MG) performing measurements or information specifying the identifier of a frame corresponding to the MG (second MG) not performing measurements. In this case, the terminal 101 may notify the base station of information specifying the SFN for performing measurements or the SFN for not performing measurements. 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 modular arithmetic operation. As an example, if MGRP=20 ms, MGL=4 ms, and gapOffset=1 are set in the measurement configuration, when the prediction mode is not performed, the start positions of the MGs are SFN=0, 2, 4, 6, 8, 10, ...On the other hand, if it is possible to measure the radio quality for periods corresponding to the other nine MGs by measuring in one of the MGs configured by the measurement configuration, the terminal 101 performs measurements in the MGs with SFN=0, 20, 40, ..., and does not perform measurements in the MGs with SFN=2, 4, 6, 8, 10, 12, 14, 16, 18, 22, 24, 26, 28, 30, 32, 34, 36, 38, 42, .... In this case, the terminal 101 may notify the base station 111 of α=10. α indicates, for example, the percentage [%] of measurements to be performed. The base station 111 may identify the MGs in which the terminal 101 will perform measurements, based on α notified by the terminal 101, using the following formula:

[0033] SFN mod ((MGRP*α) / 10)=FLOOR(gapOffset / 10) Furthermore, in the first notification, the terminal 101 can notify the base station 111 of the first MG or the second MG using expressions similar to those for the MG configuration. A method of notifying the first MG using expressions similar to those for the MG configuration will be described with reference to FIG. 8. In FIG. 8, it is assumed that the terminal 101 performs measurements using SSB signals 210 at t=0, 1, and 4, and determines not to perform measurements using SSB signals 210 at t=2 and 3. In other words, it is assumed that the terminal 101 performs measurements using MGs at t=0, 1, and 4, and determines not to perform measurements using MGs at t=2 and 3. That is, suppose that the terminal 101 determines that it can estimate the radio quality of the SSB signal 210 at t=2 and 3 using measurement values ​​in the MGs corresponding to the SSB signal 210 at t=0, 1, and 4. In this case, the terminal 101 can notify the base station 111 of the first period 801 and the second period 802 as information for identifying the first MG. At this time, because the MGL 303 is constant, the base station 111 can identify the first MG included in the period 803 in which measurement is performed and the second MG included in the period 804 in which measurement is not performed, based on the notified first period 801 and second period 802. In this case, the terminal 101 may notify the base station 111 of information for identifying the start position (radio frame and subframe) of the first period 801 or the second period 802.

[0034] The terminal 101 can notify the base station 111 of the first MG and the second MG by notifying the base station 111 of information indicated by bitmap representation for the MG configuration. A method for notifying the first MG and the second MG using bitmap representation will be described with reference to FIG. 9. In FIG. 9, it is assumed that the terminal 101 performs measurement in period 803, as in FIG. 8, and determines not to perform measurement in period 804. It is also assumed that the base station 111 has configured MGL 303 and MGRP 304 as the MG configuration. In this case, the terminal 101 can notify the first MG and the second MG using bits associated with the respective MGRP 304. In this case, the terminal 101 sets the values ​​of bits 911 and 912 associated with the first MG included in the measurement period 803 to 1. Furthermore, the terminal 101 sets the values ​​of bits 913 and 914 associated with the second MG included in the non-measurement period 804 to 0. For example, the terminal 101 may transmit a first notification to the base station 111, including a bitmap of "1100" as information indicating the first MG and the second MG. By receiving this bitmap, the base station 111 may recognize the measurement period 803 and the non-measurement period 804. In this way, the terminal 101 may notify the base station 101 by expressing, using a bitmap, a pattern regarding whether or not the terminal 101 will measure wireless quality during a predetermined period, in which a value of 1 is set when measurement is performed for each MG included in the predetermined period and a value of 0 is set when measurement is not performed. In this case, the base station 101 may recognize that this pattern is repeatedly used for each predetermined period to identify wireless quality. In this case, the terminal 101 may notify the base station 111 of information for identifying the start position (radio frame and subframe) of this pattern.

[0035] As shown in FIG. 7, when a cell is configured with each of a plurality of frequencies, if the terminal 101 can estimate the radio quality of other frequencies using the measured values ​​of some frequencies, the terminal 101 may notify the base station 111 of the frequencies to be measured or the frequencies not to be measured. As a result, the base station 111 may recognize that measurements will not be performed in the second MG corresponding to the frequencies not to be measured. In this case, the terminal 101 may notify the ARFCN-ValueNR as information specifying the frequency. The ARFCN-ValueNR is information included in the measurement target that the base station 111 sets for the terminal 101 in the measurement configuration, and is information indicating the target frequency. The terminal 101 may notify a measurement target identifier corresponding to the frequency not to be measured instead of the ARFCN-ValueNR. Since the measurement target includes the associated frequency, the base station 111 may identify the frequency to be measured or the frequency not to be measured by notifying the measurement target identifier.

[0036] In addition, when Gap Sharing, which measures multiple frequencies using the settings of one MG, is configured in the measurement configuration, the terminal 101 may determine not to measure some of the frequencies. For example, the terminal 101 may determine to measure the second frequency but not the third frequency. In this case, the terminal 101 may operate to exclude the third frequency from the target of Gap Sharing. Then, the terminal 101 may perform measurement of the second frequency in each MG configured by the measurement configuration. Furthermore, the terminal 101 may notify the base station 111 that it will not measure the third frequency. In this case, for example, the terminal 101 may notify the base station 111 of information identifying the MG corresponding to the period for identifying the radio quality of the third frequency, and may communicate with the base station 111 during the period corresponding to that MG. For example, when two SMTCs corresponding to the second frequency and the third frequency are configured for one MG setting and these two SMTCs overlap, the terminal 101 performs measurement using Gap Sharing. As an example, when MGRP = 20 ms and gapOffset = 1 are configured in the measurement setting, the start positions of the MGs are SFN = 2, 4, 6, 8, 10, .... The terminal 101 performs measurement of the second frequency in the MGs with SFN = 0, 4, 8, ..., and measures the third frequency in the MGs with SFN = 2, 6, 10, .... Since the terminal 101 can measure the radio quality of the third frequency by measuring the second frequency, when the terminal 101 determines not to measure the third frequency, it can notify the base station 111 of information specifying the third frequency on which measurement will not be performed. When the base station 111 determines, based on notification from the terminal 101, that measurements of MGs with SFN=2, 6, 10, ... corresponding to the third frequency will not be performed (will become unnecessary), it can reduce the number of MGs to be configured by notifying the terminal 101 of measurement settings of MGRP=40 ms and gapOffset=1. Alternatively, the base station 111 may maintain the measurement settings of MGRP=20 ms and gapOffset=1 so that measurements of the second frequency are performed even in the MGs associated with measurements of the third frequency by the terminal 101. In this case, the frequency of measurements of the second frequency will increase.In the above case, the terminal 101 can notify the base station 111 of information for identifying an MG to be used for measuring the third frequency for which measurement is determined not to be performed. The base station 111 can identify an MG not to be used for measurement based on the notified information and use the identified MG for another purpose.

[0037] The method by which the terminal 101 notifies the first MG and the second MG is not limited to the above. For example, the terminal 101 may notify the second MG each time. In this case, the terminal 101 may notify information indicating a period during which measurement is not performed in the first notification. For example, the terminal 101 may notify information indicating a 100 ms period, thereby indicating that measurement will not be performed in MGs included in the 100 ms period after the first notification, among the MGs configured by the measurement configuration. In this case, the base station 111 may recognize that the terminal 101 will not perform measurement in MGs included in the 100 ms period after the first notification, but will perform measurement in MGs included in the subsequent period. Note that the terminal 101 may perform notification using an RRC message such as UE Assistance Information, MAC CE, Uplink Control Information, etc. MAC CE is an abbreviation for Media Access Control Control Element.

[0038] (Operation in a Period Corresponding to an MG Where Measurement Is Not Performed) When the base station 111 receives the first notification from the terminal 101, the base station 111 can perform scheduling by assuming that resources in a period corresponding to a second MG where measurement is not performed can be used for communication with the terminal 101. Furthermore, the terminal 101 performs communication by assuming that resources in a period corresponding to the second MG can be used for communication with the base station 111. For example, the terminal 101 can perform operations such as transmitting HARQ feedback, transmitting a Scheduling Request (SR), transmitting Channel State Information (CSI), transmitting a report Sounding Reference Signal (SRS), and transmitting an UpLink Shared Channel (UL-SCH) other than message 3 in the random access procedure. Furthermore, the terminal 101 may 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 may transmit a DCI notifying scheduling of a Physical Layer Downlink Shared Channel (PDSCH) or a Physical Layer Uplink Shared Channel (PUSCH), transmit a PDSCH based on the scheduling, receive a PUSCH, etc. This increases the resources that the terminal 101 can use to communicate with the base station 111 compared to when measurements of neighboring cells are performed in all MGs, thereby enabling improved throughput and reduced delay time. In addition, the base station 111 and the terminal 101 may use the resources in the period corresponding to the second MG for purposes other than those described above.

[0039] (Method of Estimating Radio Quality) A method in which the terminal 101 estimates the radio quality for a period corresponding to a second MG using measurements of a first MG will be described. First, an example in which the terminal 101 uses some of the measurements of SSB signals periodically transmitted at one frequency to estimate the radio quality of other SSB signals 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, as shown in FIG. 6 as SSB signals 601 to 605. In this case, the terminal 101 may estimate the received power of the Nth SSB signal transmitted based on 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 referred to as a moving average method. For example, the terminal 101 may estimate the average value of the measurements of SSB signals 601 to 603 as the received power of SSB signal 604. In this case, the MG corresponding to SSB signal 604 may be identified as a second MG that does not perform measurements. Subsequently, 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 case, the MG corresponding to SSB signal 605 may be identified as the second MG. In this way, terminal 101 may perform sequential estimation by a moving average using past measurement values ​​of SSB signals. Note that 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 next to SSB signal 605. Alternatively, terminal 101 may estimate the average value of the measured 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 measured values ​​of SSB signals 601 and 602 as the received power of SSB signal 603. Alternatively, terminal 101 may estimate the average value of the measured values ​​of SSB signals 601, 602, and 604 as the received power of SSB signal 603. Furthermore, terminal 101 may make an estimation using a weighted average in which a greater weight is assigned to the measured values ​​of SSB signals that are closer to the SSB signal whose received power is to be estimated.

[0040] The 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 then calculate an estimated value of 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 , the SSB signal 605 may be estimated based on the measured value of the received signal of the SSB signal 604 and the estimated value of the SSB signal 604. In this case, the MG corresponding to the SSB signal 605 may be identified as the second MG. In addition, when terminal 101 measures SSB signals 601, 603, and 605 and estimates 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.

[0041] 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 the time corresponding to the second MG to be estimated to the variable x of this regression line. Note that the terminal 101 may update the regression line using the measured values ​​obtained while the prediction mode is being executed.

[0042] Table 1

[0043] The terminal 101 can estimate the wireless quality of other SSB signals by applying measured values ​​of 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 at each MG set by the measurement configuration as input data for the training data of the machine learning and one or more second data as correct answer data for the training data. The first data may be measured values ​​of the MG corresponding to the first MG for which measurement is performed when the prediction mode is executed, and the second data may be measured values ​​of the MG corresponding to the second MG for which measurement is not performed when the prediction mode is executed. For example, the terminal 101 determines whether it can estimate the received power of SSB signals 603 and 604 using measured values ​​of SSB signals 601 and 602 in FIG. 6 . In this case, when four consecutive periodically set MGs are grouped into one group, the received power measured at 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 at the last two MGs (corresponding to SSB signals 603 and 604) may correspond to correct data in the training data. The terminal 101 may apply, for example, SSB signals 601 and 602 as input to a trained model (inference model) generated using such training data, thereby obtaining estimated values ​​of the received power of SSB signals 603 and 604 as output. In this case, the MG corresponding to SSB signals 603 and 604 may be identified as the second MG. The 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 vary depending on the surrounding environment.Therefore, terminal 101 generates multiple trained models by changing the combination of measurement values ​​used as input data for teacher data and measurement values ​​used as correct answer data from the measurement values ​​acquired in each MG, calculates metrics using each trained model, and can determine whether or not each model can make inferences.

[0044] The estimation of radio quality performed by the terminal 101 using the measurement values ​​of the first MG during a period corresponding to the second MG is not limited to using some of the measurement values ​​of SSB signals periodically transmitted at one frequency to estimate the radio quality of other SSB signals at the same frequency. For example, if cells are formed at each of multiple frequencies, the terminal 101 may use the measurement values ​​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 the base station 112 forms cells using the second and third frequencies. In this case, the terminal 101 may estimate the received power of SSB signals 702 and 704 at the third frequency, for example, based on the measurement values ​​of SSB signals 701 and 703 received at the second frequency. For example, the terminal 101 measures the received power of each SSB signal transmitted from the base station 112 at the second and third frequencies within a certain period. The terminal 101 uses the acquired measurement values ​​to identify a correlation (estimation formula) between the measurement values ​​of the second frequency and the measurement values ​​of the third frequency. For example, the terminal 101 generates an approximation curve using the least squares method. Then, the terminal 101 estimates the received power at the third frequency from the measurement 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 measurement values ​​of the SSB signal 701 to the approximation curve. In this case, the MG corresponding to the SSB signal 702 can be identified as the second MG.

[0045] The terminal 101 may also use a machine learning estimation method when using measured values ​​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. The 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. In this case, the MG corresponding to SSB signals 702 and 704 may be identified as the second MG.

[0046] Terminal 101 may use measured values ​​in a cell formed by a specific base station to estimate the wireless quality of a cell formed by another base station. An example in which terminal 101 uses measured values ​​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 measured values ​​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 measured values ​​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 outputs. In this case, the MG corresponding to the SSB signals 602 and 604 can be identified as the second MG. In this way, the terminal 101 can estimate the radio quality of the cell formed by the base station 113 using the measurement values ​​in the cell formed by the base station 112.

[0047] Furthermore, if one base station 110 is capable of forming multiple beams, each of the beams may be used to form a cell. In this case, SSB signals may be transmitted at different times in each cell. In this case, the terminal 101 may use measurement values ​​of SSB signals transmitted in some beams to estimate the wireless quality of SSB signals transmitted in other beams. For example, assume that the base station 112 is capable of forming four beams (beam 0 to beam 3), and SSB signals 200 to 203 in FIG. 2 are transmitted in each beam. In this case, the terminal 101 may perform machine learning using the measurement values ​​of the SSB signals transmitted in beam 0 and beam 1 as input data in the training data and the measurement values ​​of the SSB signals transmitted in beam 2 and beam 3 as correct answer data in the training data, thereby acquiring a trained model (inference model). Then, the terminal 101 may input the measured values ​​of SSB signals 200 and 201 as inputs to this inference model, and obtain, as output, estimated values ​​of the received power of SSB signals 202 and 203. In this case, since there is no need to measure SSB signals 202 and 203, the terminal 101 may utilize a portion of a period in one MG for other purposes. For example, the terminal 101 may use resources corresponding to the measurement of SSB signals 202 and 203 for communication with the base station 111. In this case, the terminal 101 may notify the base station 111 of the MGL and SMTC durations required for measurement, thereby notifying the base station 111 of available resources. The base station 111 may determine that the available resources are the MG and SMTC set in the measurement configuration, excluding the notified MGL and SMTC durations.

[0048] In this way, the terminal 101 can estimate the radio quality for a period corresponding to the second MG using the measurement values ​​of the first MG by selecting and using an appropriate estimation method from various estimation methods according to the surrounding radio environment. Note that the above is an example of a radio 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. Furthermore, measurement values ​​acquired at two or more frequencies can be used. Furthermore, 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. Furthermore, 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 the inference. Furthermore, a combination of two or more of the above estimation formulas or inference models may be used. Furthermore, 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 .

[0049] (Operation at the End of Prediction Mode) After the terminal 101 issues a first notification and starts operation in the prediction mode, it may become unable to estimate wireless quality for a period corresponding to another MG using measurements acquired from some MGs. 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 terminal 101 may continuously determine whether it is possible to estimate wireless quality for a period corresponding to a second MG using measurements from a first MG, even while the prediction mode is being executed. For example, the terminal 101 may notify the base station 111 of information identifying the second MG for which measurements will be continuously performed, and perform measurement and estimation of wireless quality for this MG. Then, the terminal 101 may use measurements and estimation values ​​acquired for this MG to determine whether it is possible to estimate wireless quality for a period corresponding to the second MG using measurements from the first MG. In this case, the terminal 101 may terminate the prediction mode when it determines that it is not possible to estimate the radio quality for the period corresponding to the second MG using the measurement values ​​of the first MG. By terminating the prediction mode, the terminal 101 performs measurements in all MGs. For example, when it determines that it is not possible to estimate the radio quality for the period corresponding to the second MG using the measurement values ​​of the first MG, the terminal 101 may send a second notification to the base station 111. The second notification may include information indicating that the prediction mode will be terminated. The second notification may also include information indicating that it is not possible to estimate the radio quality for the period corresponding to the second MG using the measurement values ​​of the first MG. The second notification may also include information indicating that measurements will be performed in all MGs. The second notification may also include information indicating that the use of the pattern notified to the base station 111 when the prediction mode was started will be stopped. It should be noted that if a prediction method using an AI model is used in the prediction mode, the second notification may include a notification to deactivate the AI ​​model (model deactivation).When a cell is configured for each of a plurality of frequencies, the terminal 101 may execute the prediction mode and estimate the radio quality of the other plurality of frequencies using measurements for some of the frequencies. At this time, if it is determined that the radio quality of some of the frequencies included in the other plurality of frequencies cannot be estimated, the terminal 101 may resume measuring the radio quality for the frequencies determined to be inestimated. In this case, the terminal 101 may notify the base station 111 of information specifying the frequency at which measurement is to be resumed. The base station 111 may notify the base station 111 of the ARFCN-ValueNR or the measurement target identifier as information specifying the frequency at which measurement is to be resumed. Furthermore, in the second notification sent to the base station 111, the terminal 101 may notify the base station 111 that the pattern notified to the base station 111 when starting the prediction mode will be changed. For example, in this pattern, a bit corresponding to the MG that will perform measurement may be set to 1. The terminal 101 can perform the second notification using an RRC message such as UE Assistance Information, MAC CE, Uplink Control Information, or the like.

[0050] To determine whether to terminate the prediction mode, the terminal 101 may use the same evaluation value (metric) as when determining whether it is possible to estimate the wireless quality for the period corresponding to the second MG using the measurement values ​​of the first MG. For example, the terminal 101 may periodically perform measurements on a portion of the second MG while the prediction mode is running. In other words, the terminal 101 may notify the base station 111 of a portion of the second MG as the first MG to perform measurements. If the difference between the received power acquired by this measurement and the received power determined by estimation using the measurement values ​​of the first MG exceeds a predetermined threshold, the terminal 101 may determine that it is no longer possible to estimate the wireless quality for the period corresponding to the second MG using the measurement values ​​of the first MG. Note that the method by which the terminal 101 determines whether to terminate the prediction mode is not limited to this. For example, the terminal 101 may determine whether or not to terminate the prediction mode using evaluation values ​​(metrics) similar to those used to determine whether it is possible to estimate the wireless quality for a period corresponding to a second MG using the measurement values ​​of a first MG.

[0051] The terminal 101 may determine to terminate the prediction mode based on detecting a degradation in system performance during operation in the prediction mode. System performance includes throughput, block error rate, SINR, etc. SINR is an abbreviation for Signal to Interference and Noise Ratio. For example, when a predetermined condition is met based on the wireless quality of a specified neighboring cell, the terminal 101 may execute a handover to a cell that satisfies the predetermined condition. In this case, if the predetermined condition is met by an estimated value acquired using measurements in the first MG, the difference between the estimated value and the actual wireless quality may be large. For example, the accuracy of the estimation may decrease as the time elapsed since the terminal 101 started the prediction mode increases. In such a case, when the terminal 101 executes a handover, the system performance of the terminal 101 may deteriorate in the handover destination cell. In response to this, the terminal 101 may terminate operation in the prediction mode and perform measurements in each MG, thereby enabling another handover to an appropriate cell. For example, the terminal 101 may terminate the prediction mode based on the fact that a value indicating system performance during operation in the prediction mode has fallen below a predetermined threshold.

[0052] Furthermore, the terminal 101 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 differs from a 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 measurement values ​​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 terminal 101 may detect a change in the environment by comparing the distribution of measurement values ​​used when generating the estimation formula or inference model used for the estimation. For example, the terminal 101 may periodically compare the difference between an evaluation value calculated from the distribution of measurement values ​​used when generating the estimation formula or inference model used in the prediction mode 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 value, median value, variance, etc. of the received power measured over a certain period of time. A plurality of these may be used as evaluation values ​​for the determination.

[0053] In this way, even while terminal 101 is executing the prediction mode, it uses specified metrics to determine whether it is possible to continue to use the measurement values ​​of the first MG to estimate the wireless quality for the period corresponding to the second MG, and terminates the prediction mode based on the determination that estimation is not possible.This makes it possible to use the period corresponding to some MGs for other purposes without measuring them in situations where estimation is possible, and to accurately determine the wireless quality by measuring each MG in situations where estimation is not possible.

[0054] Although the above description has been given using an example in which the radio quality for a period corresponding to a second MG is estimated using the measurement value of a first MG, the radio quality for a period corresponding to the MG may also be estimated using the radio quality of communication in the serving cell. For example, when communicating at a first frequency and measuring the radio quality of a second frequency in an MG, the second frequency may be estimated using the measurement value of the first frequency. In this case, the terminal 101 may operate such that, among the MGs configured by the measurement configuration for measuring the second frequency, the terminal 101 measures the second frequency in the first MG and does not measure the second frequency in the second MG. The terminal 101 may then determine whether to continue the prediction mode by comparing the measurement value of the second frequency measured in the first MG with the estimated value of the radio quality of the second frequency estimated from the measurement value at the first frequency.

[0055] (Variation 1) The terminal 101 may associate an estimation method to be used in the prediction mode with a second MG that is not measured when the prediction mode is executed using the estimation method, and share the association information with the base station 111 in advance. The terminal 101 and the base station 111 may share an inference model to be used in the prediction mode, or may share information capable of identifying training data to be used when generating the inference model. The information capable of identifying training data may be information capable of identifying an MG at which measurements used as input data are measured, or an MG at which measurements used as correct data are measured. The information capable of identifying training data may be information capable of identifying a frequency at which measurements used as input data are measured, or a frequency at which measurements used as correct data are measured. In this way, by sharing information capable of identifying the inference model to be used by the terminal 101 in the prediction mode, the base station 111 can identify a first MG or frequency at which measurements are performed while the prediction mode is executed, or a second MG or frequency at which measurements are not performed. In this case, in the first notification issued when starting operation in the prediction mode, the terminal 101 may notify the base station 111 of information specifying the first MG, the second MG, etc., but may notify the base station 111 of information specifying the estimation method to be used in the prediction mode. For example, if multiple estimation methods or inference models are shared between the terminal 101 and the base station 111, and the base station 111 is able to identify the first MG or the second MG, etc., by notifying which estimation method to use, the terminal 101 may notify the base station 111 of information identifying the estimation method or inference model to be used, instead of notifying the base station 111 of information specifying the first MG or the second MG, etc., in the first notification.

[0056] In addition, when one or more inference models to be used in the prediction mode are predetermined, the terminal 101 may determine whether to execute the prediction mode based on whether the distribution of measurement values ​​acquired in the MG set by the measurement setting 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 in the MG set by the measurement setting, 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 terminal 101 may determine to execute the prediction mode using the inference model that satisfies the condition.

[0057] (Variation 2) The base station 111 can provide information about the prediction function and prediction mode of the terminal 101 to the other base stations 112 and 113. For example, if the base stations 112 and 113 are candidates for the handover destination of the terminal 101, the base station 111 notifies the information about the terminal 101 in advance, so that the prediction mode can be continued as is after the terminal 101 actually performs the handover.

[0058] 10 shows an example of a sequence when the terminal 101 performs a handover from the base station 111 to the base station 112. This operation can be initiated when the wireless quality of the SSB signal identified by the terminal 101 in the cell 122 formed by the base station 112 satisfies a predetermined condition. First, it is assumed that the terminal 101 is communicating with the base station 111 (S1001). Then, based on the predetermined condition being satisfied in the terminal 101, the base station 111 notifies the base station 112 of a message for initiating a handover procedure (S1002). For example, the base station 111 notifies the base station 112 of a Handover Preparation Information message (S1002). In the Handover Preparation Information message, the base station 111 can provide information about the terminal 101 and instructions notified to the terminal 101. For example, the base station 111 may notify the base station 112 that the terminal 101 has a prediction function, that the terminal 101 is permitted to use the prediction mode, that the terminal 101 is executing the prediction mode, etc. Note that when the terminal 101 is executing the prediction mode, the base station 111 may notify the base station 112 of the measurement settings of the terminal 101, information identifying the first MG and the second MG, information identifying the estimation method (inference model, etc.) used by the terminal 101, etc. In response to the Handover Preparation Information message, the base station 112 notifies the base station 112 of a Handover Command message (S1003). In the Handover Command message, the base station 112 may notify the terminal 101 of permission to use the prediction mode, etc. The information included in the Handover Command message is notified to the terminal 101 by an RRC Connection Reconfiguration message (S1004). Note that if the base station 112 does not support operation in the prediction mode, the Handover Command message does not include information indicating permission to use the prediction mode. In this way, the terminal 101 can determine whether to continue the prediction mode in the base station 112, which is the handover destination, based on the RRC Connection Reconfiguration message received from the base station 111.That is, if the use of the prediction mode is permitted, the terminal 101 continues the prediction mode, and if the use of the prediction mode is not permitted, the terminal 101 ends the prediction mode. Note that the base station 111 may notify the terminal 101 of whether the prediction mode can be used after handover. (Circuit Configuration) An example configuration of the terminal 101 and base station 110 as described above will be described. FIG. 11 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 include a processor 1101, a ROM 1102, a RAM 1103, a storage device 1104, and a communication circuit 1105. The processor 1101 is a computer including one or more processing circuits, such as a general-purpose CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit). The processor 1101 reads and executes programs stored in the ROM 1102 or the storage device 1104, thereby performing the overall processing of the device and each of the above-mentioned processes. The ROM 1102 is a read-only memory that stores information such as programs related to processes executed by the terminal 101 and the base station 110, various parameters, and the like. The RAM 1103 functions as a workspace when the processor 1101 executes programs and is a random access memory that stores temporary information. The storage device 1104 is, for example, a removable external storage device. The communication circuit 1105 is, for example, configured to include circuits for wired 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 1105 for LTE or 5G. (Functional Configuration) FIG. 12 is a diagram illustrating an example of the functional configuration of the base station 110. The base station 110 includes, as its functions, a measurement setting unit 1201, an information communication unit 1202, and a scheduling unit 1203, for example. FIG. 12 illustrates the functional configuration of the base station 110 of this embodiment, and omits, for example, the general configuration of the base station 110. These functional units can be realized, for example, by the processor 1101 executing a program stored in the ROM 1102 or the storage device 1104 and controlling the communication circuit 1105 as necessary. However, this is not limiting, and for example, dedicated hardware for realizing each function may be provided.

[0059] The measurement setting unit 1201 performs settings for the terminal 101 to perform measurements. For example, the measurement setting unit 1201 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. The measurement settings configured by the measurement setting unit 1201 are notified to the terminal 101 via the communication circuit 1105. The information communication unit 1202 exchanges information with the terminal 101. For example, the information communication unit 1202 may receive notifications such as that the terminal 101 has a prediction function, that the terminal 101 executes a prediction mode, or that the terminal 101 terminates the prediction mode. Furthermore, when the terminal 101 executes the prediction mode, the information communication unit 1202 may acquire information specifying the first MG and the second MG. Furthermore, the information communication unit 1202 may notify the terminal 101 that use of the prediction mode is permitted. Note that the information communication unit 1202 may share estimation methods, metric calculation methods, etc. with the terminal 101. The scheduling unit 1203 allocates radio resources to the terminal 101. For example, when the terminal 101 is executing the prediction mode, the scheduling unit 1203 performs scheduling assuming that the second MG can be used for communication.

[0060] FIG. 13 is a diagram showing an example of the functional configuration of the terminal 101. The terminal 101 is configured to include, as its functions, a setting acquisition unit 1301, a measurement unit 1302, an information notification unit 1303, a quality identification unit 1304, a metric determination unit 1305, and an information communication unit 1306, for example. FIG. 13 shows 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 1101 executing a program stored in the ROM 1102 or the storage device 1104 and controlling the communication circuit 1105 as necessary. However, this is not limited to this, and, for example, dedicated hardware for realizing each function may be provided.

[0061] The setting acquisition unit 1301 acquires measurement settings from the base station 110. For example, the setting acquisition unit 1301 acquires an RRC message including MeasConfig from the base station 110, and identifies the MG set for measurement, the frequency to be measured, the timing to measure, etc. The measurement unit 1302 measures the wireless quality of a neighboring cell. For example, the measurement unit 1302 measures the wireless quality of a specified frequency based on information such as the MG, the frequency to be measured, and the timing to measure acquired by the setting acquisition unit 1301. The information notification unit 1303 performs notification to the base station 110. For example, the information notification unit 1303 notifies the base station 110 that its own device has a prediction function, that a prediction mode will be executed, that the prediction mode will be terminated, etc. Furthermore, when notifying that its own device has a prediction function, the information notification unit 1303 may also notify the base station 110 of an estimation method supported by its own device, a metric calculation method, etc. Furthermore, when executing the prediction mode, the information notification unit 1303 may notify the base station 110 of information identifying the first MG, the second MG, etc. The quality identification unit 1304 identifies wireless quality. For example, when the prediction mode is not being executed, the quality identification unit 1304 may identify wireless quality using measurement values ​​for each MG measured by the measurement unit 1302. Furthermore, when executing the prediction mode, the quality identification unit 1304 identifies wireless quality for a period corresponding to each MG by using the measurement values ​​for the first MG measured by the measurement unit 1302 and estimating wireless quality for a period corresponding to the second MG using these measurement values. The metric determination unit 1305 determines whether it is possible to estimate wireless quality for a period corresponding to the second MG using the measurement values ​​for the first MG. For example, the metric determination unit 1305 may output an estimated value of wireless quality for at least one of the MGs configured by the measurement setting based on measurement values ​​at other MGs, and determine that estimation is possible based on the difference between the estimated value and the measurement value at the at least one MG being smaller than a predetermined threshold.Furthermore, the metric determination unit 1305 may determine that estimation is possible based on the fact that a difference between a measurement value for an MG for which at least one measurement has been performed among the MGs configured by the measurement configuration and a measurement value for another MG configured within a predetermined period from the MG is smaller than a predetermined threshold. The information communication unit 1306 communicates with the base station 110. For example, when the prediction mode is being executed, the information communication unit 1306 communicates with the base station 110, assuming that resources for a period corresponding to an MG for which measurement is not performed can be used for communication.

[0062] As described above, according to this embodiment, the terminal measures the radio quality of a frequency in at least one first MG configured by the measurement configuration acquired from the base station, and determines whether it is possible to estimate the radio quality of the frequency in a period corresponding to a second MG using the measurement results. Then, based on whether it is possible to estimate the radio quality of the frequency, the terminal sends a first notification to the base station indicating that it will not perform measurements based on the measurement configuration in a period corresponding to the second MG. Furthermore, after sending the first notification, the terminal estimates the radio quality of the frequency in a period corresponding to the second MG without performing measurements based on the configuration information in the period corresponding to the second MG. With this configuration, when it is possible to estimate the radio quality of a frequency in a period corresponding to the second MG among the MGs configured by the measurement configuration, the terminal can use the second MG for another purpose without using it for measurements. This allows the terminal to reduce the period used for measurements when determining the radio quality of neighboring cells, 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."

[0063] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention.

[0064] This application claims priority based on Japanese Patent Application No. 2024-133224, filed August 8, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A terminal device having communication means for communicating with a base station based on the cellular communication standard of the Third Generation Partnership Project (3GPP), comprising: acquisition means for acquiring from the base station configuration information for setting a Measurement GAP (MG) for measuring the wireless quality of signals transmitted at frequencies other than those used for communication with the base station; measurement means for measuring the wireless quality of the frequency in at least one first MG set by the configuration information; notification means for sending to the base station a first notification indicating that measurements based on the configuration information will not be performed during a period corresponding to a second MG set by the configuration information, based on the measurement results in the first MG, and based on the fact that it is possible to estimate the wireless quality of the frequency during a period corresponding to the second MG; and identification means for, after sending the first notification, estimating the wireless quality of the frequency during a period corresponding to the second MG without performing measurements based on the configuration information during the period corresponding to the second MG.

2. The terminal device according to claim 1, wherein the first notification includes information that can identify the second MG.

3. The terminal device of claim 1 or 2, wherein the first notification includes information indicating a predetermined pattern regarding whether or not to measure the wireless quality of the frequency during a predetermined period of time, the predetermined pattern including information specifying whether each MG included in the predetermined period of time is a first MG in which measurements based on the setting information are performed, or a second MG in which measurements based on the setting information are not performed, and the terminal device measures the wireless quality of the frequency at the first MG while repeatedly using the predetermined pattern for each predetermined period of time, and estimates the wireless quality of the frequency during the period corresponding to the second MG.

4. The terminal device according to claim 3, wherein the notification means sends a second notification to the base station indicating that the specified pattern will be changed or that use of the specified pattern will be stopped if, after sending the first notification, it becomes impossible to determine by estimation the radio quality of the frequency during the period corresponding to the second MG.

5. A terminal device as claimed in any one of claims 1 to 4, further comprising a determination means for determining whether it is possible to estimate the radio quality of the frequency during a period corresponding to the second MG using the measurement results in the first MG.

6. The terminal device described in claim 5, wherein the identification means outputs an estimated value of the wireless quality of the frequency for at least one of the first MGs based on measurement values ​​at other MGs among the first MGs, and the determination means determines that it is possible to estimate the wireless quality at the frequency for a period corresponding to a second MG using the measurement results at the first MG based on the difference between the estimated value and the measurement value at the at least one of the first MGs being smaller than a predetermined threshold.

7. The terminal device described in claim 5, wherein the determination means determines that it is possible to estimate the radio quality of the frequency during a period corresponding to a second MG using the measurement results at the first MG based on the difference between the measurement value for at least one of the first MGs where the measurement was performed and the measurement value for another MG set within a predetermined period from the MG where the measurement was performed being smaller than a predetermined threshold.

8. The terminal device according to any one of claims 5 to 7, wherein the acquisition means further acquires information specifying a determination method for making the determination from the base station.

9. A terminal device as described in any one of claims 1 to 8, further comprising a receiving means for receiving permission to use the estimation from the base station, and wherein the identifying means, if the permission is not received, identifies the wireless quality of the frequency in all MGs set by the setting information by measuring the wireless quality.

10. A terminal device as described in any one of claims 1 to 9, wherein the communication means, when not measuring the radio quality of the frequency in the second MG, communicates with the base station assuming that resources for the period corresponding to the second MG can be used for communication.

11. A base station that communicates with a terminal device based on the cellular communication standard of the Third Generation Partnership Project (3GPP), comprising: a notification means that notifies the terminal device of configuration information that sets a Measurement GAP (MG) for the terminal device to measure the wireless quality of signals transmitted at frequencies other than the frequency used for communication with the terminal device; and a receiving means that receives, in the terminal device, a first notification indicating that the terminal device will not measure the wireless quality based on the configuration information during a period corresponding to a second MG set by the configuration information, when it is possible to estimate the wireless quality of the frequency during a period corresponding to the second MG set by the configuration information using a measurement result of the wireless quality of the frequency in at least one first MG set by the configuration information.

12. A control method executed by a terminal device that communicates with a base station based on the cellular communication standard of the Third Generation Partnership Project (3GPP), the control method comprising: acquiring from the base station configuration information that sets a Measurement GAP (MG) for measuring the radio quality of signals transmitted at frequencies other than a frequency used for communication with the base station; measuring the radio quality of the frequency in at least one first MG set by the configuration information; using the measurement results in the first MG, based on the fact that it is possible to estimate the radio quality of the frequency in a period corresponding to a second MG set by the configuration information, sending a first notification to the base station indicating that measurements based on the configuration information will not be performed in a period corresponding to the second MG; and after sending the first notification, determining by estimation the radio quality of the frequency in a period corresponding to the second MG without performing measurements based on the configuration information in the period corresponding to the second MG.

13. A control method executed by a base station communicating with a terminal device based on the cellular communication standard of the Third Generation Partnership Project (3GPP), comprising: notifying the terminal device of configuration information that sets a Measurement GAP (MG) for the terminal device to measure the wireless quality of signals transmitted at frequencies other than the frequency used for communication with the terminal device; and, when the terminal device can estimate the wireless quality of the frequency during a period corresponding to a second MG set by the configuration information using a measurement result of the wireless quality of the frequency in at least one first MG set by the configuration information, receiving a first notification indicating that the terminal device will not measure the wireless quality based on the configuration information during a period corresponding to the second MG.

14. A program for causing a computer to function as each of the means possessed by the terminal device according to any one of claims 1 to 10.

15. A program for causing a computer to function as each of the means possessed by the base station according to claim 11.

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