Terminal device, base station device, method for controlling terminal device, and method for controlling base station device

Abstract

The present invention improves the efficiency of power saving operations related to wireless communication between a terminal device and a base station device. This terminal device includes a control unit, a transmission unit, and a reception unit, and uses a primary cell and a secondary cell. The reception unit receives a synchronization signal setting related to a synchronization signal to be transmitted on demand to the secondary cell, a report setting related to a report of a measurement result of the synchronization signal, and control information indicating the start or stop of the transmission of the synchronization signal. The control unit evaluates a measurement event condition for the secondary cell indicated in the report setting when the control information shows the start of the transmission of the synchronization signal, and does not evaluate the measurement event condition when the control information shows the stop of the transmission of the synchronization signal. The transmission unit transmits a measurement report message including the measurement result of the secondary cell to the base station device when an establishment condition for the measurement event condition is satisfied on the basis of the measurement result of the secondary cell.

Description

Terminal device, base station device, control method for terminal device, and control method for base station device

[0001] The present invention relates to a terminal device, a base station device, a control method for a terminal device, and a control method for a base station device.

[0002] In the current network, traffic from mobile terminals (such as smartphones and feature phones) occupies most of the network resources. Also, the traffic used by mobile terminals tends to increase in the future.

[0003] Also, in addition to the traffic used by mobile terminals, for example, the deployment of IoT (Internet of Things) services (such as traffic systems, monitoring systems for smart meters and devices, etc.) is underway. Therefore, the network is required to support services with diverse requirement conditions. To support such diverse services, for example, in the communication standard of the fifth generation mobile communication (5G or NR (New Radio)), support for many use cases classified into eMBB (Enhanced Mobile BroadBand), Massive MTC (Machine Type Communications), and URLLC (Ultra-Reliable and Low Latency Communication) is assumed, and the standard has been established.

[0004] In the 3rd Generation Partnership Project (3GPP), which is an international standardization project, the extension technology of the above communication standard is still being continuously studied and standardized.

[0005] In order to reduce the power consumption of the network side (that is, base station devices and core network devices) in 3GPP, the technology of NES (Network Energy Savings) is being studied (Non-Patent Document 1).

[0006] 3GPP TR 38.864 V18.0.0 (2022-12) R2-2406669

[0007] Base station equipment periodically transmits synchronization signals within a cell. Terminal equipment uses the synchronization signal to synchronize its uplink / downlink with the base station equipment (cell) it accesses, and to measure the downlink quality of the cell. Base station equipment transmits the synchronization signal and the physical broadcast channel (described later) as a synchronization signal / physical broadcast channel block (SSB / PBCH block). In 3GPP, as one of the network power reduction technologies, a method is being considered to reduce the power consumption of base station equipment by introducing On-Demand SSB, which does not transmit SSB periodically but transmits it as needed (on-demand transmission).

[0008] However, in conventional communication systems, SSB within a cell is defined as always being transmitted (or never being transmitted (SSB-less)). Therefore, in the case of SSB transmitted as needed (on-demand SSB), if a terminal device performs SSB measurement within a cell according to conventional procedures, it will also measure sections where On-demand SSB is not being transmitted, resulting in incorrect measurement results and, as a result, the transmission of unintended measurement reports. Non-patent document 2 discloses the problems with measurement methods when applying such On-demand SSB to secondary cells, but it does not mention at all the problem of measurement reports being transmitted at unintended times.

[0009] Therefore, one disclosure is to improve the efficiency of power saving related to wireless communication between terminal equipment and base station equipment when applying network power reduction technology that appropriately transmits SSB.

[0010] A terminal device using a primary cell and a secondary cell, comprising: a receiving unit that receives synchronization signal settings for synchronization signals transmitted on demand to the secondary cell from a base station device, reporting settings for reporting the measurement results of the synchronization signals, and control information that instructs the start or stop of the transmission of synchronization signals; a control unit that, when the control information indicates the start of the transmission of synchronization signals, performs an evaluation of the measurement event conditions for the secondary cell instructed by the reporting settings, and does not perform an evaluation of the measurement event conditions when the control information indicates the stop of the transmission of synchronization signals; and a transmitting unit that, when the conditions for fulfilling the measurement event conditions are met based on the measurement results of the secondary cell, transmits a measurement report message including the measurement results of the secondary cell to the base station device.

[0011] One disclosure states that when applying network power reduction technology, the efficiency of power saving related to wireless communication between terminal equipment and base station equipment can be improved.

[0012] This figure shows an example of the configuration of a wireless communication system related to the embodiment. This figure shows an example of the cell configuration related to the embodiment. This figure shows an example of the functional configuration of a terminal device related to the embodiment. This figure shows an example of the functional configuration of a base station device related to the embodiment. This figure shows an example of the measurement procedure for On-demand SSB. This figure shows an example of the reporting procedure for On-demand SSB. This figure shows an example of the link relationships between the measurement target identifier, the reporting setting identifier, and the measurement identifier. This figure shows an example of a conventional SSB measurement method. This figure shows an example of the hardware configuration of a terminal device. This figure shows an example of the hardware configuration of a base station device.

[0013] Embodiments of the present invention will be described in detail below with reference to the drawings. The problems and embodiments described herein are examples and do not limit the scope of the rights of this application. In particular, even if the wording of the description differs, the technology of this application is applicable as long as it is technically equivalent and does not limit the scope of the rights. Furthermore, each embodiment can be combined as appropriate, as long as there is no inconsistency in the processing content.

[0014] The wireless communication system according to embodiments of the present invention may utilize known technologies as appropriate. Applicable known technologies may include, for example, 5G (NR), Beyond 5G, 5G-Advanced, or other wireless communication methods including future wireless communication technologies. The wireless communication system according to embodiments of the present invention targets NR, but is not limited thereto. For example, embodiments of the present invention are also applicable to LTE (Long Term Evolution) and LTE-Advanced. Furthermore, they are also applicable to wireless communication systems that use NR as part of the wireless communication system.

[0015] Furthermore, embodiments of the present invention are applicable to any wireless communication system comprising at least terminal equipment and base station equipment, and are also applicable to future wireless communication systems. In the following description, LTE and LTE-Advanced will also be referred to as E-UTRA (Evolved Universal Terrestrial Radio Access), but they have the same meaning.

[0016] Hereinafter, embodiments of the base station equipment, terminal equipment, and wireless communication system disclosed in this application will be described with reference to the drawings. Note that the following embodiments are not intended to limit the disclosed technology.

[0017] <Wireless Communication System> Figure 1 shows an example of the configuration of a wireless communication system 1 according to an embodiment of the present invention. The wireless communication system 1 according to the embodiment consists of, for example, a terminal device 10, a base station device 20A, a base station device 20B, and a core network 30. The wireless communication system 1 is, for example, a wireless communication system that corresponds to NES, in other words, a wireless communication system that supports the functions of NES. The functions of NES include at least a series of functions for realizing On-demand SSB. Base station devices 20A and 20B are base station devices 20 that notify (set, instruct) the terminal device 10 of measurement setting information for measuring On-demand SSB, and support carrier aggregation technology that aggregates and transmits / receives multiple carriers. When base station devices 20A and 20B are not distinguished, they are simply referred to as base station device 20. Also, there may be multiple terminal devices 10.

[0018] The terminal device 10 may be a wireless terminal such as a mobile phone, smartphone, PDA (Personal Digital Assistant), tablet, wearable device, personal computer, vehicle, or any other device or equipment with wireless communication capabilities (such as a sensor device). Alternatively, the terminal device 10 may be referred to as a wireless communication device, communication device, receiving device, mobile station, UE (User Equipment), user device, etc.

[0019] The base station equipment 20 may be a small radio base station such as a macro radio base station or pico radio base station (including microwave radio base stations, femto radio base stations, etc.), or a radio base station of various sizes, and may be described as a wireless communication device, communication device, transmitting device, etc.

[0020] In the wireless communication system 1, the base station equipment 20 and the core network 30 provide wireless communication services to the terminal device 10. The core network 30 has functions such as managing service subscriber information, managing sessions for voice calls, and managing the location registration of the terminal device 10. The core network 30 also transmits control data and / or user data to the terminal device 10 via the base station equipment 20.

[0021] The core network 30 may be a 5G Core (5GC) in 5G (NR), or an Evolved Packet Core (EPC) in 4G (E-UTRA). Alternatively, it may encompass a network with future core network functions for 6G and beyond. Furthermore, the connection method between the core network 30 and the base station equipment 20 may be an NSA (Non-Stand Alone) method or an SA (Stand Alone) method.

[0022] The 5G base station equipment 20 connected to the 5GC is a gNB, and the 4G base station equipment 20 connected to the EPC is an eNB. Furthermore, the 5G base station equipment is physically or logically connected to each other via an Xn interface. Similarly, the 4G base station equipment is physically or logically connected to each other via an X2 interface.

[0023] The area (coverage area) formed by the base station device 20 is sometimes called a "cell." E-UTRA and 5G are cellular communication systems constructed from multiple cells. In the wireless communication system according to the embodiment of the present invention, either TDD (Time Division Duplex) or FDD (Frequency Division Duplex) may be applied, and different methods may be applied to each cell.

[0024] The technology of aggregating multiple cells with different frequencies is called carrier aggregation. In carrier aggregation, the cell used for determining mobility and radio link failure is called the primary cell (PCell), and the cell used as an additional resource is called the secondary cell (SCell). A primary cell within a secondary cell group is called a primary secondary cell (PSCell).

[0025] On-demand SSB is generally applied in secondary cells. When the base station device 20 is not transmitting On-demand SSB (sleep state), it stops transmitting and receiving all physical signals and channels other than predetermined ones in the cell, thereby saving power by cutting off the standby power of the wireless equipment inside the base station device 20. The predetermined physical signals and channels are, for example, PSS / SSS and PBCH related to On-demand SSB.

[0026] Figure 2 is an example of a cell configuration when applying On-demand SSB. In Figure 2, for example, cell 200 is the primary cell when performing carrier aggregation, and cell 201 is a secondary cell (On-demand SSB Cell) that supports On-demand SSB.

[0027] Cell 200 is a cell that uses frequency F1 as its carrier wave, and cell 201 is a cell that uses a different frequency F2 as its carrier wave. Cells 200 and 201 may be cells of the same base station equipment 20, or they may be cells of different base station equipment 20. For example, base station equipment 20A may constitute the primary cell (cell 200), and base station equipment 20B may constitute the secondary cell (cell 201). Base station equipment 20 may set up carrier aggregation on the downlink when terminal equipment 10 supports simultaneous reception of frequencies F1 and F2, and may also set up carrier aggregation on the uplink when terminal equipment 10 supports simultaneous transmission of frequencies F1 and F2. However, the number of downlink cells aggregated during carrier aggregation must be equal to or greater than the number of uplink cells aggregated.

[0028] In the example shown in Figure 2, the correspondence between cell 200 and cell 201 is illustrated, but the size and positional relationship of both cells are merely illustrative, and other correspondences are possible. For example, the primary cell (cell 200) and the secondary cell (cell 201) may be the same size, or the secondary cell (cell 201) may be larger. Cell 200 may contain multiple cells 201 (i.e., multiple cells 201 exist in the area covered by cell 200).

[0029] The sleep state is, for example, a state in which some of the functions related to transmission and reception of the base station device 20 are stopped, and at the same time, power supply to internal equipment related to transmission and reception is suppressed, and the base station device 20 does not transmit some messages, and does not transmit or receive corresponding physical signals or physical channels. Furthermore, when the sleep state of a cell (for example, cell 201) is released (the application of a predetermined power saving technology is stopped), or when the sleep state is temporarily released, it may transition to a state in which the cell can perform normal wireless communication (non-sleep state).

[0030] Terminal device 10 is a communication device that wirelessly connects to base station device 20 and performs at least data transmission and reception. Furthermore, terminal device 10 is a communication device that corresponds to the functions of NES, that is, a communication device that supports the functions of NES.

[0031] The base station device 20 may be configured as, for example, a CU (Centralized Unit), a DU (Distributed Unit), and a RU (Radio Unit). The CU is connected to the core network. The DU is connected to the terminal device 10 via the RU, for example. The communication path between the CU and the DU is implemented, for example, by a front-haul interface (F1 interface). Multiple DUs may be connected to a single CU.

[0032] In the example shown in Figure 1, the data (DL data, downlink data) transmitted from the core network 30 to the terminal device 10 is transmitted from the core network 30 to the base station device 20, and then transmitted (transferred) from the base station device 20 to the terminal device 10.

[0033] The data (UL data, uplink data) transmitted from the terminal device 10 to the core network 30 is transmitted from the terminal device 10 to the base station device 20, and then transmitted (transferred) from the base station device 20 to the core network 30.

[0034] The terminal device 10 and the base station device 20 transmit and receive RRC messages (also called RRC signaling) at the Radio Resource Control (RRC) layer. Furthermore, the terminal device 10 and the base station device 20 transmit and receive MAC control elements (MAC CE) at the Medium Access Control (MAC) layer.

[0035] RRC messages are transmitted as RRC PDUs (Protocol Data Units) and mapped to logical channels (LCHs) such as the Common Control Channel (CCCH), Dedicated Control Channel (DCCH), Paging Control Channel (PCCH), Broadcast Control Channel (BCCH), or Multicast Control Channel (MCCH).

[0036] A MAC CE is transmitted as a MAC PDU (or MAC subPDU). A MAC subPDU is equivalent to a Service Data Unit (SDU) in the MAC layer with header information defined, for example, in 8-bit units, and a MAC PDU contains one or more MAC subPDUs.

[0037] Next, as physical channels and physical signals related to the embodiment, there are at least the following: synchronization signals (Primary Synchronization Signal, Secondary Synchronization Signal), Physical Broadcast Channel (PBCH), Physical Random Access Channel (PRACH), Physical Downlink Control Channel (PDCCH), Channel State Information-Reference Signal (CSI-RS), Physical Uplink Control Channel (PUCCH), Physical Downlink Shared Channel (PDSCH), Physical Uplink Shared Channel (PUSCH), Scheduling Reference Signal (SRS), and Demodulation Reference Signal (DMRS), but a detailed explanation is omitted.

[0038] <Terminal Device> Figure 3 is a diagram showing an example of the functional configuration of a terminal device 10 related to the embodiment. As shown in Figure 3, the terminal device 10 includes, for example, a processing unit 11, a control unit 13, a receiving unit 15, a transmitting unit 17, and a transmitting / receiving antenna unit 19. The processing unit 11 is configured to include, for example, a wireless resource processing unit 111 and a measurement processing unit 113. Note that the functional configuration of the terminal device 10 shown in Figure 3 is merely an example, and the functional classifications and names of each functional block may differ as long as they can perform the operations related to the embodiment. In addition, there may be one or more blocks that realize other functions.

[0039] The processing unit 11 generates control information for controlling the receiving unit 15 and the transmitting unit 17, for example, and outputs it to the control unit 13. The processing unit 11 also performs processing related to the wireless resource control layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, and the Media Access Control (MAC) layer, for example.

[0040] The wireless resource processing unit 111 manages various setting information (RRC parameters, information elements (IE)) of the terminal device 10. For example, the wireless resource processing unit 111 generates information to be placed on each channel of the physical uplink and outputs that information to the transmission unit 17. In addition, based on instructions from the base station device 20, the wireless resource processing unit 111 performs measurements of the cell in the area and surrounding cells, starts and stops On-demand SSB measurements, starts and stops transmission and reception processing, performs DL synchronization procedures (cell search), UL synchronization procedures (random access procedures), acquires and reacquires system information, evaluates measurement events related to handover, performs a series of processes related to handover procedures, and performs a series of processes related to measurement reporting procedures.

[0041] The measurement processing unit 113 performs a series of control processes related to the detection and measurement of On-demand SSB. For example, it holds the settings related to On-demand SSB measurement notified by the base station device 20 and determines the measurement timing. The measurement processing unit 113 also performs the following actions based on the start or stop instruction for On-demand SSB measurement notified by the base station device 20: determining whether to measure the downlink power of the On-demand SSB, filtering the measurement results of the On-demand SSB, determining whether to start or stop the measurement event evaluation, and performing the measurement event evaluation (evaluation of the conditions for the establishment or departure of the measurement event).

[0042] The control unit 13 performs various controls in the terminal device 10. For example, the control unit 13 generates a control signal or control data for controlling the receiving unit 15 and the transmitting unit 17 based on the control information from the processing unit 11. Also, the control unit 13 controls the uplink transmission to the base station device 20, the scheduling request transmission, and the downlink reception from the base station device 20 respectively based on the determination information regarding the transmission control from the measurement processing unit 113.

[0043] The receiving unit 15 separates, demodulates, and decodes various signals received from the base station device 20 via the transceiver antenna unit 19 based on the control signal given from the control unit 13. The receiving unit 15 outputs the decoded information to the processing unit 11.

[0044] The transmitting unit 17 generates, for example, a physical uplink signal based on the control signal given from the control unit 13, and performs encoding, modulation, etc. on the physical uplink signal or physical uplink channel given from the processing unit 11. The transmitting unit 17 multiplexes various signals and transmits them to the base station device 20 via the transceiver antenna unit 19.

[0045] Note that the processing unit 11 and the control unit 13 are realized, for example, by a processor system including a processor and a memory. In this case, the processor provides the functions of the processing unit 11 and the control unit 13 by executing a program describing the operation of the terminal device 10 described later. Also, the processing unit 11 and the control unit 13 may be realized by one processor system or by a plurality of processor systems. Alternatively, the processing unit 11 and the control unit 13 may be realized by a DSP (Digital Signal Processor) or a hardware circuit or the like.

[0046] <Base Station Device>Figure 4 is a diagram showing an example of the functional configuration of the base station device 20 according to the embodiment. As shown in Figure 4, the base station device 20 includes, for example, a processing unit 21, a control unit 23, a receiving unit 25, a transmitting unit 27, and a transmitting / receiving antenna unit 29. The processing unit 21 is configured to include, for example, a radio resource processing unit 211 and a measurement processing unit 213. Note that the functional configuration of the base station device 20 shown in Figure 4 is merely an example, and the functional classification and the names of the functional blocks may be different as long as the operations related to the embodiment can be executed. Also, there may be one or more blocks for realizing other functions.

[0047] The processing unit 21 generates, for example, control information for controlling the receiving unit 25 and the transmitting unit 27 and outputs it to the control unit 23. The processing unit 21 executes, for example, processes related to the radio resource control layer, the packet data convergence protocol layer, the radio link control layer, and the medium access control layer.

[0048] The radio resource processing unit 211 generates, for example, downlink data, RRC messages, and MAC control elements arranged in the physical downlink shared channel PDSCH and outputs them to the transmitting unit 27. Also, the radio resource processing unit 211 generates control signals or control data arranged in the physical downlink control channel PDCCCH and outputs them to the transmitting unit 27. Further, the radio resource processing unit 211 manages various setting information of the terminal device 10. Based on signals from the terminal device 10 or notifications by RRC messages, the radio resource processing unit 211 executes start and stop of transmission / reception processing, start of UL synchronization procedure (random access procedure), update of system information, start and stop of On-demand SSB transmission, adjustment of transmission angle of beams, generation of parameters related to On-demand SSB transmission procedure, generation of parameters related to On-demand SSB measurement procedure, parameters related to On-demand SSB (On-demand SSB SCell) reporting procedure, etc.

[0049] The measurement processing unit 213 performs a series of control processes related to On-demand SSB transmission. For example, the measurement processing unit 213 determines whether On-demand SSB transmission is necessary based on instructions from a higher layer or information indicating the status of the terminal device 10 transmitted by the terminal device 10. The measurement processing unit 213 also adjusts the timing of On-demand SSB transmission and simultaneously generates information indicating the start or stop of On-demand SSB transmission. Furthermore, the measurement processing unit 213 generates information instructing the terminal device 10 of the parameters necessary for receiving On-demand SSB, and information instructing the terminal device 10 of the parameters necessary for reporting the On-demand SSB measurement results.

[0050] The control unit 23 performs various controls on the base station device 20. For example, the control unit 23 generates control signals or control data to control the receiving unit 25 and the transmitting unit 27 based on control information from the processing unit 21. The control unit 23 also controls the timing of starting and stopping On-demand SSB transmission based on judgment information regarding On-demand SSB transmission from the measurement processing unit 213.

[0051] The receiving unit 25 separates, demodulates, and decodes various signals received from the terminal device 10 or core network 30 via the transmitting / receiving antenna unit 29, based on control signals provided by the control unit 23. The receiving unit 25 outputs the decoded information to the processing unit 21.

[0052] The transmitting unit 27 generates, for example, On-demand SSB and downlink reference signals based on control signals provided by the control unit 23. The transmitting unit 27 transmits signals to the terminal device 10 via the transmitting / receiving antenna unit 29 by encoding, modulating, and multiplexing various information provided by the processing unit 21.

[0053] Furthermore, the transmitting unit 27 transmits data to the terminal device 10, another base station device 20, or the core network 30. The receiving unit 25 receives data from the terminal device 10, another base station device 20, or the core network 30.

[0054] The processing unit 21 and the control unit 23 are implemented, for example, by a processor system including a processor and memory. In this case, the processor provides the functions of the processing unit 21 and the control unit 23 by executing a program that describes the operation of the base station device 20, which will be described later. The processing unit 21 and the control unit 23 may be implemented by a single processor system or by multiple processor systems. Alternatively, the processing unit 21 and the control unit 23 may be implemented by a DSP or hardware circuit, etc.

[0055] <Carrier Aggregation> Carrier aggregation is a technique that aggregates multiple different uplink or downlink frequency bands (component carriers) and treats them as a single frequency band. The component carriers to be aggregated may be in a continuous frequency band, or they may be discontinuous in whole or in part. It is also possible to aggregate continuous or discontinuous component carriers within the same frequency band. In the following discussion, the terms component carrier and cell may not be used to distinguish between them.

[0056] The base station device 20 can increase or decrease the number of uplink or downlink component carriers allocated to the terminal device 10 based on various factors such as the amount of data buffer in the connected terminal device 10's transmission data, the reception quality of the terminal device 10, the load within the cell, and the Quality of Service (QoS).

[0057] Furthermore, component carriers are classified into primary component carriers (PCCs) and secondary component carriers (SCCs). A primary component carrier typically consists of a pair of uplink and downlink component carriers, as indicated by system information, and is the frequency band that the terminal device 10 uses as a reference for measurement and control, detection of downlink radio link failures, and transmission of uplink control channels. The base station device 20 may set a primary component carrier for each terminal device 10.

[0058] A secondary component carrier is a frequency band allocated to terminal devices 10 other than the primary component carrier. Terminal devices 10 do not need to detect radio link failures on the secondary component carrier. The base station device 20 may instruct terminal devices 10 to activate / deactivate the secondary component carrier allocated for power saving purposes.

[0059] The primary component carrier cell configured in the terminal device 10 is a primary cell (PCell), and the secondary component carrier cell is a secondary cell (SCell). In other words, the terminal device 10 performing carrier aggregation is connected to the base station device 20 via the primary cell and one or more secondary cells.

[0060] <Measurement Settings and Measurement Events> The base station device 20 notifies the terminal device 10 of the measurement settings (setting, specifying, and transmitting), causing the terminal device 10 to perform a measurement of the frequency (for example, the NR and / or EUTRA frequency). The measurement settings are notified, for example, by an RRC message (for example, RRCReconfiguration).

[0061] The measurement settings include at least the following parameters:

[0062] (1) Measurement object(s) A measurement object (measObject) contains information about the target frequency that the terminal device 10 will measure, and multiple measurement objects can be set in list format. The base station device 20 can specify intra-frequency measurements, inter-frequency measurements, and inter-RAT (Radio Access Technology) E-UTRA measurements as measurement objects. In the case of inter-RAT E-UTRA measurements, the E-UTRA frequency is set as the measurement object.

[0063] Furthermore, the base station device 20 may include a list of cells to which a cell-specific offset is assigned, a block cell list, and an authorized cell list as measurement targets. A cell-specific offset is an offset value added to the measurement result during measurement; a block cell list is a list indicating cells that are not applicable (excluded) for event evaluation (described later) or measurement reporting; and an authorized cell list is a list indicating cells that are applicable (targeted) for event evaluation or measurement reporting. In order to manage the measurement targets of the terminal device 10, the base station device 20 sets a measurement target identifier (measObjectId) for each measurement target, and can add, change, or delete measurement targets of the terminal device 10 using the measurement target identifier.

[0064] (2) Reporting configuration(s) A reporting configuration (reportConfig) contains information about the measurement report, and one or multiple reporting configurations are set for each measurement target in list format. The base station device 20 manages the reporting configurations of the terminal device 10, and sets a reporting configuration identifier (reportConfigId) for each reporting configuration, and can add, change, or delete reporting configurations of the terminal device 10 using the reporting configuration identifier. The reporting configuration further includes measurement type information (reportType) that specifies the timing of measurement reporting, such as periodic reporting information (periodical) which is reported periodically, and event trigger information (eventTriggered) which is triggered using event conditions. For periodic reporting information, parameters such as the reporting period are set in the periodic reporting configuration (PeriodicalReportConfig). For event trigger information, parameters such as the event identifier (described later) and offset are set in the event trigger configuration (EventTriggerConfig).

[0065] (3) Measurement identity(ies) A ​​measurement identity (measId) is an identifier used to link (associate, link) one measurement object identifier (measObjectId) and one report configuration identifier (reportConfigId). Multiple measurement identity(ies) can be set in list format. Multiple report configurations may be linked to one measurement object by a measurement identity, or multiple measurement objects may be linked to the same report configuration. The measurement identity is included in the measurement report and transmitted to the base station device 20 to report measurement events that meet the trigger conditions. The base station device 20 can use the measurement identity to add, change, or delete the measurement identity(ies) of the terminal device 10.

[0066] Figure 7 shows an example of the link relationships between the measurement target identifier, the report setting identifier, and the measurement identifier. In the example in Figure 7, the base station device 20 notifies (sets, instructs) the terminal device 10 of two different measurement targets and two different report settings as measurement settings. The base station device 20 sets a separate measurement target identifier (measObjectId#0, measObjectId#1) for each measurement target, and sets a separate measurement target identifier (reportConfigId#0, reportConfigId#1) for each report setting.

[0067] When the base station device 20 associates (links) a measurement target identifier #0 (measObjectId#0) with a report configuration identifier #0 (reportConfigId#0), it instructs the terminal device 10 to use a measurement identifier #0 (measId#0) in the measurement configuration to manage the link information. The base station device 20 may link multiple measurement targets to a single report configuration. For example, it is possible to associate a measurement target identifier #1 (measObjectId#1) with a report configuration identifier #0 (reportConfigId#0) and set a different measurement identifier #1 (measId#1). Furthermore, the base station device 20 may link multiple report configurations to a single measurement target. For example, it is possible to associate a measurement target identifier #1 (measObjectId#1) with a report configuration identifier #1 (reportConfigId#1) and set a different measurement identifier #2 (measId#2).

[0068] In this way, the base station device 20 can manage the frequency and measurement content (measurement type) to be measured by the terminal device 10 by setting a measurement identifier for each correspondence (link) between the measurement target and the reporting settings. The terminal device 10 can determine the frequency and measurement content (measurement type) to be measured by the base station device 20, which sets a measurement identifier for each correspondence (link) between the measurement target and the reporting settings, and evaluate the measurement results.

[0069] Regarding the measurement targets for NR, the terminal device 10 measures and reports on the resident cells (also called serving cells), listed cells, and detected cells. Listed cells are those included in the list notified by the base station device 20. Detected cells refer to other cells that the terminal device 10 has independently detected.

[0070] The measured cell quality (received quality, measured quality, measurement result) is calculated by measuring the Synchronization Signal Block (SSB) or the Channel State Information Reference Signal (CSI-RS). Cell quality can be expressed using one of the following: RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Received Signal Strength Indicator), SINR (Signal to Interference plus Noise Ratio), or path loss.

[0071] The measurement events (Measurement event(s)) evaluated by the terminal device 10 are specified by the base station device 20. Measurement events are specified in the event trigger settings within the reporting settings and are managed by an event identifier (eventId). When a measurement event is triggered (successful), the terminal device 10 generates a measurement report message and sends it to the base station device 20. The conditions (measurement type) that indicate the trigger for sending the measurement report message are specified by the base station device 20, such as periodic reports and event-triggered reports.

[0072] Each measurement event has a defined applicable cell that is subject to evaluation. For example, the applicable cell for measurement event A1 is the local cell. The applicable cell for measurement event A3 is the cell detected at the target frequency (adjacent cell) that is linked to the reporting settings that include the local cell and measurement event A3.

[0073] The terminal device 10 initiates the measurement reporting procedure when the measurement type (reportType) is an event-triggered report, the measurement result meets the conditions indicated by the measurement event, and the condition continues to be met for a predetermined period of time thereafter. In other words, the measurement reporting procedure is initiated when the measurement result of the applicable cell satisfies (establishes) the measurement event corresponding to the event identifier specified in the reporting settings included in the measurement settings, and the measurement event continues to be satisfied for a predetermined period of time. At this time, the terminal device 10 reports the measurement result of the cell corresponding to the measurement identifier that satisfied the measurement event to the base station device 20.

[0074] Here, the reception quality of the cell in the area is defined as Ms, the reception quality of the primary cell (or primary secondary cell) as Mp, the reception quality of the surrounding cell as Mn, the frequency offset corresponding to the frequency in the area as Offp, the frequency offset corresponding to the frequency of the surrounding cell as Offn, the cell-specific offset corresponding to the cell in the area as Ocp, the cell-specific offset corresponding to the surrounding cell as Ocn, the event-specific offset value as Off, the hysteresis value as Hys, and the quality-based threshold as Thresh (Thresh1, Thresh2). The base station device 20 transmits these parameters to the terminal device 10 using RRC messages as part of the measurement settings. The base station device also sets a parameter TTT (TimeToTrigger) on the terminal device 10 that indicates the length of a predetermined time for the occurrence of a measurement event.

[0075] The terminal device 10 determines whether the measurement results of the cell, after filtering (L3 filtering) for averaging / smoothing the measurement results, satisfy the event entry condition set by the base station device 20. Similarly, after the event entry condition is satisfied, the terminal device 10 determines whether the measurement results of the cell satisfy the event leaving condition.

[0076] For example, for measurement event A1, which is determined by whether the cell quality of a cell in the area exceeds a predetermined threshold, formula 1 shows the event occurrence conditions for measurement event A1, and formula 2 shows the event exit conditions for measurement event A1. Similarly, for measurement event A3, which is determined by whether the cell quality of surrounding cells exceeds that of a primary cell (or primary secondary cell), formula 3 shows the event occurrence conditions for measurement event A3, and formula 4 shows the event exit conditions for measurement event A3.

[0077] [Formula 1] Ms - Hys > Thresh

[0078] [Equation 2] Ms + Hys < Thresh

[0079] [Equation 3] Mn + Ofn + Ocn - Hys > Mp + Ofp + Ocp + Of

[0080] [Equation 4] Mn + Ofn + Ocn + Hys < Mp + Ofp + Ocp + Of

[0081] Other measurement events include measurement event A2, which is determined by whether the cell quality of the cell in the area falls below a predetermined threshold; measurement event A4, which is determined by whether the cell quality of the surrounding cells exceeds a predetermined threshold; and measurement event A5, which is determined by whether the cell quality of the primary cell (or primary secondary cell) falls below a threshold AND the cell quality of the surrounding cells exceeds a predetermined threshold.

[0082] An example of how the terminal device 10 determines the cell to which a measurement event applies will be explained using the following procedure A.

[0083] <Step A> If AS security has been activated successfully, the UE shall: 1> for each measId included in the measIdList within VarMeasConfig: 2> if the corresponding reportConfig includes a reportType set to eventTriggered or periodical: 3> if the corresponding measObject concerns NR: 4> if the eventA1 or eventA2 is configured in the corresponding reportConfig: 5> consider only the serving cell to be applicable;

[0084] Procedure A is performed for each measurement identifier (measId) that links the measurement object (measObject) for which NR is targeted, and the report configuration (reportConfig) whose report type (reportType) is either event-triggered (eventTriggered) or periodic (periodical). In L3 (RRC), terminal device 10 considers the cell in question as an applicable cell for measurement event A1 or measurement event A2 if the event-triggered report is set to measurement event A1 or measurement event A2 in the report configuration.

[0085] <On-demand SSB> On-demand SSB is one of the power-saving technologies applied to the base station equipment 20. Instead of periodically transmitting the secondary cell's SSB during carrier aggregation, it transmits it as needed (on-demand transmission). In other words, On-demand SSB is an SSB that is transmitted temporarily. The signal format and multiplexing method of On-demand SSB can be the same as that of conventional SSB. That is, SSB includes a synchronization signal and a physical broadcast channel (PBCH). The synchronization signal consists of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). Hereafter, unless otherwise specified, SSB and synchronization signal will be described as synonymous without distinction. On-demand SSB is an example of a synchronization signal.

[0086] When the base station device 20 sets (adds) a secondary cell to the terminal device 10, it sets information indicating that the secondary cell is an On-demand SSB compatible cell. Based on this information, the terminal device 10 determines that the added secondary cell is an On-demand SSB compatible cell. The terminal device 10 also determines that it is necessary to measure the downlink quality of the secondary cell based on On-demand SSB.

[0087] Furthermore, a secondary cell that supports On-demand SSB includes both the case where periodic transmission of all SSBs other than On-demand SSB is not performed (first case), and the case where a secondary cell that transmits conventional SSB (typically with a longer transmission period than conventional SSB) also transmits On-demand SSB (typically with a shorter transmission period than conventional SSB) (second case).

[0088] <SSB Measurement Method> Here, the terminal device 10 calculates the cell quality (reception quality) for each cell by measuring SSB (On-demand SSB) or the channel state information reference signal (CSI-RS). Cell quality can be expressed using one of the following: RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Received Signal Strength Indicator), SINR (Signal to Interference plus Noise Ratio), or path loss.

[0089] The base station device 20 may set a measurement window (SMTC: SS (Synchronization Signal) / PBCH block Measurement Timing Configuration) indicating the SSB measurement interval (measurement timing) for each cell in the area or for each frequency for the terminal device 10. The terminal device 10 measures the SSB in the interval set based on the SMTC. The SMTC consists of an offset value, a period, and a measurement interval.

[0090] Figure 8 is an example of a diagram showing the relationship between conventional SMTC and SSB. In Figure 8, the SMTC periodicity is set to, for example, 40 milliseconds (40ms). The base station device 20 sets information for the terminal device 10 indicating the SMTC periodicity and an offset value (for example, the distance from the beginning of the SFN (system frame number) shown in subframes) to adjust the SMTC start timing. The terminal device 10 also sets a window for the SSB measurement interval (duration) for each SMTC period and performs SSB detection and measurement within that window. The SMTC may also be specified for each frequency indicated by the measurement object included in the measurement configuration for the connected terminal device 10.

[0091] In Figure 8, the base station device 20 sets the SMTC period (P100) at a certain frequency to be measured to 40 ms. The terminal device 10 detects and measures SSB at the frequency to be measured, taking the set offset into consideration. Time T100 indicates the start timing of the SMTC (SMTC window) considering the offset. Time T101 indicates the end timing of the SMTC that started at T100. That is, the period from time T100 to time T101 indicates the length of the SMTC interval (duration). The SMTC is repeated every period P100. That is, the SMTC is repeated at time T102, which is period P100 after time T100, and again at time T103, which is period P100 after time T102 (and so on).

[0092] Taking the above points into consideration, embodiments of the present invention will be described with reference to the drawings. In the description of embodiments of the present invention, if a specific explanation of known functions or configurations related to embodiments of the present invention would obscure the gist of the embodiments of the present invention, such detailed explanation will be omitted.

[0093] <First Embodiment> Figure 5 is an example of a sequence diagram showing the On-demand SSB procedure of the terminal device 10 and base station device 20 according to the first embodiment.

[0094] The terminal device 10 in Figure 5 is a terminal device 10 that supports NES functionality, and the base station device 20 sets (notifies, instructs) the configuration information (On-demand SSB configuration information) necessary for the terminal device 10 to measure the On-demand SSB corresponding to the secondary cell. The base station device 20 notifies the On-demand SSB configuration information using RRC messages. The On-demand SSB configuration information may also include SMTC configuration information used for the detection and measurement of On-demand SSB. The method for setting SMTC configuration information will be explained later in Figure 6.

[0095] RRC messages include, for example, individual RRC messages, RRCReconfiguration messages, and RRCSetup messages. In Figure 5, an example of an RRC message is described as an RRCReconfiguration message. The configuration information required to measure On-demand SSB (On-demand SSB information) may include synchronization signal settings. In addition, RRC messages may include at least one of the following: information regarding synchronization signal settings for synchronization signals transmitted on demand via secondary cells, and information regarding reporting settings for reporting the measurement results of synchronization signals.

[0096] Furthermore, information regarding synchronization signal settings for synchronization signals transmitted on demand via secondary cells is, for example, information for setting Measurement objects(s) for synchronization signals transmitted on demand. Information regarding reporting settings for reporting the measurement results of synchronization signals may also include, for example, information for setting Reporting configuration(s). Note that RRC messages may also include control information, for example, instructing the start (activation) or stop (deactivation) transmission of synchronization signals. Information regarding synchronization signal settings may be referred to as "synchronization signal settings." Similarly, information regarding reporting configurations may be referred to as "reporting configurations." Furthermore, information regarding synchronization signal settings may be included in the information regarding reporting configurations.

[0097] Furthermore, the base station device 20 in Figure 5 transmits On-Demand SSB when it receives information indicating the status of the terminal device 10, or when it determines that it is necessary (for example, when the amount of accumulated downlink buffer exceeds a predetermined threshold or when the amount of data buffer reported by the terminal device 10 exceeds a predetermined threshold). Similarly, when the base station device 20 determines that it is not necessary (for example, when the amount of accumulated downlink buffer falls below a predetermined threshold), it stops transmitting On-Demand SSB.

[0098] The base station device 20 may activate the secondary cell (On-demand SSB Cell) at the same time as starting On-demand SSB transmission, or it may start On-demand SSB transmission while the secondary cell remains deactivated. Similarly, the base station device 20 may deactivate the secondary cell at the same time as stopping On-demand SSB transmission, or it may stop On-demand SSB transmission while the secondary cell remains activated.

[0099] In Figure 5, in step S100, the base station device 20 notifies the system of an instruction to add a secondary cell that supports On-demand SSB (On-demand SSB Cell) and the On-demand SSB configuration information for that secondary cell via an RRC message (RRCReconfiguration). At this time, the secondary cell to be added is set to a deactivation state by default. The terminal device 10 obtains one or more On-demand SSB configuration information and adds the specified secondary cell to start the carrier aggregation transmission and reception procedure.

[0100] Furthermore, when the terminal device 10 completes the setting procedure related to the settings received in step S100, it generates an RRC message (RRCReconfigurationComplete) indicating the completion of the setting and transmits it to the base station device 20 (step S101). Alternatively, the On-demand SSB setting information may be described as information that sets a time window for measuring the synchronization signal / physical broadcast channel block that is temporarily transmitted to the secondary cell.

[0101] On-demand SSB configuration information may be included in the secondary cell configuration (SCell configuration) or in the measurement object corresponding to the secondary cell frequency. Alternatively, SSB frequency information (absoluteFrequencySSB) and physical cell ID (PCI) from the on-demand SSB configuration information may be included in the secondary cell configuration. Furthermore, SMTC configuration parameters related to SSB measurement (SMTC settings) may be included in the measurement object.

[0102] Furthermore, the base station device 20 sets at least information combining the period and offset value as SMTC (periodicityAndOffset) and information indicating the interval length of the SMTC window (duration). In addition, the base station device 20 sets index information (0, 1, ..., N (where N is a natural number)) (SMTC index) for each combination of parameters in order to manage multiple On-demand SSB configuration information. The base station device 20 may not explicitly notify the index information (SMTC index) and may assign index numbers in descending order to multiple SMTCs set in a list format. That is, the terminal device 10 may consider the index number of the SMTC set first in the list to be "0", and the index number of the SMTC set second in the list to be "1".

[0103] Next, in step S102, the terminal device 10 transmits information about the terminal device 10 (UE information) to the base station device 20. The information about the terminal device 10 may be, for example, a BSR (Buffer Status Report) indicating the buffer status of the uplink, or an SR (Scheduling Request) indicating an uplink scheduling request. The information sent in step S102 may be transmitted as uplink control information (UCI: Uplink Control Information) included in PUCCH, as MAC CE, or as an RRC message.

[0104] The base station device 20 determines the necessity of transmitting On-demand SSB in the On-demand SSB SCell based on, for example, information from the terminal device 10 received in step S102, downlink buffer information held by the base station device 20, or control information related to cell control of the terminal device 10 (step S103). If the determination in step S103 determines that On-demand SSB transmission is necessary, the base station device 20 transmits information to the terminal device 10 instructing it to activate On-demand SSB in step S104. The base station device 20 also starts transmitting On-demand SSB at a predetermined timing after step S104 (step S105). On the other hand, if the determination in step S103 determines that On-demand SSB transmission is unnecessary, the base station device 20 maintains its current state and terminates the sequence shown in Figure 5.

[0105] When terminal device 10 receives an instruction from base station device 20 to activate On-demand SSB (step S104), it attempts to detect the SSB (On-demand SSB) transmitted to the secondary cell at an appropriate timing based on the instruction (step S105) and simultaneously starts measurement.

[0106] The information instructing the activation of the On-demand SSB in step S104 may be Downlink Control Information (DCI) included in the PDCCH, a MAC CE containing information instructing activation for each secondary cell, or an RRC message. When using a MAC CE, it may be transmitted simultaneously with the SCell Activation / Deactivation MAC CE.

[0107] The base station device 20 may transmit SMTC index information as information instructing the activation of On-demand SSB in step S104. The terminal device 10 applies the SMTC parameters corresponding to the instructed index information to the secondary cell (On-demand SSB cell). More specifically, the terminal device 10 derives the transmission timing of On-demand SSB (reception timing from the perspective of the terminal device 10) based on the SMTC period and offset value corresponding to the instructed index information, and attempts to detect and / or measure On-demand SSB within the interval of the SMTC window. The base station device 20 instructs the terminal device 10, using the index information, to use the SMTC corresponding to the transmission period of On-demand SSB to be transmitted to the secondary cell. Note that the SMTC index information is just one example; other information that instructs the activation of the corresponding SMTC may be used.

[0108] In other words, when the base station device 20 sets the periods of multiple On-demand SSBs for the terminal device 10, it sets multiple SMTCs (SMTC settings) in the On-demand SSB setting information and sets index information to associate the On-demand SSB periods with the SMTCs. Furthermore, by notifying the terminal device 10 of the index information, the base station device 20 implicitly notifies the terminal device 10 of the transmission period and transmission timing of the On-demand SSB to be transmitted to the secondary cell, enabling the terminal device 10 to appropriately detect and measure the On-demand SSB. That is, the base station device 20 can implicitly notify the terminal device 10 of the transmission period of the On-demand SSB by associating it with the SMTC settings. The terminal device 10 can determine the transmission period of the On-demand SSB based on the SMTC settings specified by the base station device 20.

[0109] Figure 6 is an example of a sequence diagram showing the reporting procedure for On-Demand SSB of the terminal device 10 and base station device 20 according to the first embodiment.

[0110] In Figure 6, L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) in the terminal device 10 indicate that processing of different layers within the terminal device 10 is being performed in parallel. Typically, L1 represents the physical layer, L2 represents the PDCP layer, RLC layer, and MAC layer, and L3 represents the RRC layer. In the case of uplink transmission, the terminal device 10 transfers the transmission data from the upper layer to the lower layer (in the order of L3, L2, L1), and in the case of downlink reception, it transfers the received data from the lower layer to the upper layer (in the order of L1, L2, L3). Unless otherwise specified, the explanation of the data flow between these layers in the terminal device 10 is omitted.

[0111] Note that the lower and upper layers differ depending on their correspondence. Specifically, from the perspective of the RRC layer (L3), the MAC layer (L2) and the physical layer (L1) are lower layers. Also, from the perspective of the MAC layer (L2), the RRC layer (L3) is an upper layer and the physical layer (L1) is a lower layer, and from the perspective of the physical layer (L1), the MAC layer (L2) and the RRC layer (L3) are upper layers. Hereafter, the upper layer may be referred to as the first layer and the lower layer as the second layer.

[0112] In step S200, the base station device 20 sends an RRC message (RRCReconfiguration). The contents set in RRCReconfiguration are the same as in step S100 in Figure 5, so the details are omitted. Note that the processing related to RRCReconfigurationComplete is not shown.

[0113] Here, the base station device 20 does not instruct activation of On-demand SSB transmission when setting On-demand SSB to the secondary cell. L3 of the terminal device 10 applies the settings specified in the RRC message and understands that activation of On-demand SSB has not been instructed. Then, based on the On-demand SSB setting information, L3 of the terminal device 10 provides L1 with the information necessary for measuring On-demand SSB and instructs that the measurement results of On-demand SSB are not required (step S201).

[0114] When terminal device 10's L1 is instructed by a higher layer that the measurement results for the On-demand SSB are unnecessary, it stops transferring the L1 measurement results for the On-demand SSB to the higher layer (steps S202, S203). Terminal device 10's L3 does not receive notification of the L1 measurement results from the lower layer (L1), and therefore cannot obtain the L3 measurement results (cell measurement results) for the secondary cell. As a result, the measurement event conditions for the secondary cell are not evaluated, and the measurement event conditions corresponding to that cell are not met.

[0115] Alternatively, in step S201, L3 of the terminal device 10 provides L1 with the information necessary for measuring the On-demand SSB based on the On-demand SSB setting information, and also instructs that the On-demand SSB measurement process is unnecessary.

[0116] When terminal device 10's L1 is instructed by a higher layer that the measurement process for the On-demand SSB is unnecessary, it stops the L1 measurement of the On-demand SSB itself (step S202). Similarly in this case, terminal device 10's L3 does not receive notification of the L1 measurement result from the lower layer (L1), and therefore cannot obtain the L3 measurement result (cell measurement result) for the secondary cell. As a result, the measurement event condition for the secondary cell is not evaluated, and the measurement event condition corresponding to that cell is not met.

[0117] Next, in step S204, the base station device 20 transmits information to the terminal device 10 instructing the activation of On-demand SSB. Figure 5 shows an example in which information instructing the activation of On-demand SSB is notified using MAC CE (for example, On-demand SSB Activation / Deactivation MAC CE). In this case, the MAC CE is received at L2 of the terminal device 10. The information transmitted in step S204 is an example of control information instructing the start (activation) or stop (deactivation) of the synchronization signal transmission.

[0118] L2 of terminal device 10 activates the On-demand SSB corresponding to the secondary cell specified by MAC CE. Then, L2 of terminal device 10 instructs L1 that the measurement results of the On-demand SSB of the said secondary cell are required (step S205).

[0119] When L1 of terminal device 10 receives a signal from the upper layer indicating that measurement results for On-demand SSB are required, L1 starts (or resumes) transferring the L1 measurement results for On-demand SSB to the upper layer (steps S206, S207). L3 of terminal device 10 uses the L1 measurement results notified from the lower layer (L1) to obtain the L3 measurement results (cell measurement results) for the secondary cell. Based on the cell measurement results, terminal device 10 evaluates the measurement event conditions for the secondary cell and determines whether the measurement event conditions corresponding to the cell have been met. If the measurement event conditions for the secondary cell have been met, terminal device 10 generates a measurement report message containing an identifier indicating the met measurement event and the cell measurement results for the secondary cell, and transmits it to base station device 20.

[0120] Alternatively, when the terminal device 10 receives a signal from a higher layer indicating that measurement results for the On-demand SSB are required, L1 of the terminal device 10 starts (resumes) the L1 measurement process for the On-demand SSB and transfers the obtained L1 measurement results to the higher layer (steps S206, S207).

[0121] In other words, the lower layer (L1) of the terminal device 10 starts or stops the forwarding of the L1 measurement report of the On-demand SSB SCell to the upper layer (L3) in response to an instruction from the upper layer to start or stop the transmission of On-demand SSB. Alternatively, the lower layer (L1) of the terminal device 10 starts or stops the L1 measurement of the On-demand SSB SCell itself in response to an instruction from the upper layer to start or stop the transmission of On-demand SSB.

[0122] A modified version of Figure 6 is described below. In Figure 6, the base station device 20 does not instruct the activation of On-demand SSB transmission in the RRC message (RRCReconfiguration) in step S200. However, the base station device 20 can also instruct the activation of On-demand SSB transmission in RRCReconfiguration. In this case, L3 of the terminal device 10 applies the settings specified in the RRC message and understands that the activation of On-demand SSB has been instructed. Based on the On-demand SSB setting information, L3 of the terminal device 10 provides L1 with the information necessary for measuring On-demand SSB and may also instruct L1 that the measurement results of On-demand SSB or measurement processing is required.

[0123] Furthermore, if the terminal device 10 is instructed to release an On-demand SSB cell via an RRC message (RRCReconfiguration), L3 of the terminal device 10 may instruct L1 of the released secondary cell not to perform the above-mentioned measurement process corresponding to On-demand SSB, but to return to the conventional measurement method.

[0124] Furthermore, Figure 6 shows an example in which the base station device 20 includes information instructing the activation of On-demand SSB in the MAC CE in step S204. However, if On-demand SSB transmission is already activated, the base station device 20 can also use the MAC CE to instruct the deactivation of On-demand SSB transmission. In this case, L2 of the terminal device 10 deactivates the On-demand SSB corresponding to the secondary cell specified in the MAC CE. Then, L2 of the terminal device 10 may instruct L1 to provide the measurement result of the On-demand SSB of the secondary cell, or to indicate that measurement processing is unnecessary. The information transmitted in step S204 is an example of control information that instructs the start (activation) or stop (deactivation) of the synchronization signal transmission.

[0125] On-demand SSB SCell may also be deactivated based on a deactivation timer for each secondary cell (SCell deactivation timer) or other L2 timers (e.g., an On-demand SSB deactivation timer). That is, if On-demand SSB transmission is deactivated by the expiration of an L2 timer measured by the terminal device 10, L2 of the terminal device 10 may instruct L1 to provide the measurement result for the On-demand SSB of the secondary cell, or to indicate that measurement processing is unnecessary.

[0126] Thus, according to the first embodiment, the base station device 20 can transmit information to the terminal device 10 in a secondary cell that supports On-demand SSB, which causes the terminal device 10 to decide whether to start or stop evaluating measurement events corresponding to On-demand SSB. The terminal device 10, in a first layer that processes the information transmitted from the base station device 20, decides whether to start or stop evaluating measurement events corresponding to On-demand SSB, and can also instruct a second layer, which is lower than the first layer of the terminal device 10, on the result of that decision.

[0127] As a result, the event conditions are not met in the secondary cell, allowing the terminal device 10 to suppress the occurrence of measurement events. Therefore, unnecessary operation of the base station device 20 caused by the measurement event report of the terminal device 10 can be avoided, thereby improving the power saving efficiency of the base station device 20.

[0128] <Second Embodiment> The second embodiment is described below. Note that the configurations, functions, or procedures common to both the first and second embodiments will not be explained. In other words, the following will mainly describe the differences from the first embodiment.

[0129] The first embodiment suppressed the occurrence of measurement events related to On-demand SSB SCell by instructing L1 from a higher layer to stop notification of L1 measurement results or to stop the L1 measurement process. On the other hand, the second embodiment provides a method for suppressing the occurrence of measurement events at a higher layer (L3) without stopping the L1 measurement process or notification of L1 measurement results.

[0130] The terminal device 10 evaluates the measurement event set based on the L3 measurement result. Therefore, the occurrence of measurement events in the upper layer (L3) can be suppressed by either (1) not using the L3 measurement result by On-demand SSB SCell to evaluate the measurement event, or (2) not starting the evaluation of the measurement event until On-demand SSB transmission is started, or a combination of these methods.

[0131] An example of the procedure for implementing method (1) is shown in the following steps 1 to 3. The underlined steps indicate the changes from the conventional method for determining which cells the terminal device 10 is an applicable cell. Note that the changes are merely examples, and each may be implemented using a different procedure than those shown below.

[0132] <Procedure 1> If AS security has been activated successfully, the UE shall: 1> for each measId included in the measIdList within VarMeasConfig: 2> if the corresponding reportConfig includes a reportType set to eventTriggered or periodical: 3> if the corresponding measObject concerns NR: 4> if the eventA1 or eventA2 is configured in the corresponding reportConfig and: 4> if the serving cell is not on-demand SSB SCell or, if the serving cell is on-demand SSB SCell and on-demand SSB activation indication has been indicated from the lower layers, 5> consider only the serving cell to be applicable; 4> if the serving cell is on-demand SSB SCell and on-demand SSB deactivation indication has been indicated from the lower layers, 5> consider the serving cell to be not applicable;

[0133] Step 1 is performed for each measurement identifier (measId) that links the measurement object (measObject) for which NR is targeted, and the report configuration (reportConfig) whose report type (reportType) is either event-triggered or periodic. At L3 (RRC), if the event-triggered report is set to measurement event A1 or measurement event A2 in the report configuration, the terminal device 10 considers the secondary cell to be applicable to measurement event A1 or measurement event A2 if the cell in the area is not an On-demand SSB cell, or if the cell in the area is an On-demand SSB cell and activation of On-demand SSB transmission has been instructed from a lower layer.

[0134] On the other hand, in L3 (RRC), if the cell in the area is a secondary cell (On-demand SSB cell) and the lower layer has instructed the deactivation of On-demand SSB transmission, the terminal device 10 does not consider the secondary cell to be an applicable cell for measurement event A1 or measurement event A2.

[0135] <Procedure 2> If AS security has been activated successfully, the UE shall: 1> for each measId included in the measIdList within VarMeasConfig: 2> if the corresponding reportConfig includes a reportType set to eventTriggered or periodical: 3> if the corresponding measObject concerns NR: 4> if the eventA1 or eventA2 is configured in the corresponding reportConfig: 5> if the corresponding reportConfig does not include od-ssbConfig, or if the corresponding reportConfig includes od-ssbConfig and on-demand SSB activation indication has been indicated from the lower layers; 6> consider only the serving cell to be applicable; 5> if the corresponding reportConfig includes od-ssbConfig and on-demand SSB deactivation indication has been indicated from the lower layers; 6> consider only the serving cell to be not applicable;

[0136] Step 2 is performed for each measurement identifier (measId) that links the measurement object (measObject) for which NR is targeted, and the report configuration (reportConfig) whose report type (reportType) is either event-triggered or periodic. In L3 (RRC), if measurement event A1 or measurement event A2 is set as an event-triggered report in the report configuration, the terminal device 10 considers the secondary cell to be applicable to measurement event A1 or measurement event A2 if the report configuration does not contain information identifying an On-demand SSB cell (e.g., od-ssbConfig), or if the report configuration contains information identifying an On-demand SSB cell and activation of On-demand SSB transmission is instructed from a lower layer.

[0137] On the other hand, terminal device 10 does not consider the secondary cell to be applicable to measurement event A1 or measurement event A2 if, in L3 (RRC), the reporting setting includes information identifying an On-demand SSB cell, and the lower layer has instructed the deactivation of On-demand SSB transmission.

[0138] <Procedure 3> If AS security has been activated successfully, the UE shall: 1> for each measId included in the measIdList within VarMeasConfig: 2> if the corresponding reportConfig includes a reportType set to eventTriggered or periodical: 3> if the corresponding measObject concerns NR: 4> if the eventA1 or eventA2 is configured in the corresponding reportConfig: 5> if the corresponding measObject does not include od-ssbConfig, or if the corresponding measObject includes od-ssbConfig and on-demand SSB activation indication has been indicated from the lower layers; 6> consider only the serving cell to be applicable; 5> if the corresponding measObject includes od-ssbConfig and on-demand SSB deactivation indication has been indicated from the lower layers; 6> consider only the serving cell to be not applicable;

[0139] Step 3 is performed for each measurement identifier (measId) that links the measurement object (measObject) for which NR is targeted, and the report configuration (reportConfig) whose report type (reportType) is either event-triggered or periodic. In L3 (RRC), if measurement event A1 or measurement event A2 is set as an event-triggered report in the report configuration, the terminal device 10 considers the secondary cell to be applicable to measurement event A1 or measurement event A2 if the measurement object does not contain information identifying an On-demand SSB cell (e.g., od-ssbConfig), or if the measurement object contains information identifying an On-demand SSB cell and activation of On-demand SSB transmission is instructed from a lower layer.

[0140] On the other hand, if the terminal device 10, in L3 (RRC), includes information that identifies the measurement target as an On-demand SSB cell, and has been instructed from a lower layer to deactivate On-demand SSB transmission, it does not consider the secondary cell to be an applicable cell for measurement event A1 or measurement event A2.

[0141] Up to this point, we have explained measurement events A1 and A2 as examples, but for other measurement events (for example, measurement events A3 to A6), any method can be adopted as long as each measurement event can be prevented from occurring by not considering the cells to be applied. For example, in measurement event A3, it is acceptable to not consider the On-demand SSB SCell as an applicable cell for measurement event A3, or to not consider other cells in the area, as well as surrounding cells with the same frequency as the set measurement target, as applicable cells for measurement event A3.

[0142] Furthermore, for example, in measurement event A6, it is also acceptable to not consider the On-demand SSB SCell as an applicable cell for measurement event A6, or to not consider surrounding cells with the same frequency as the measurement target corresponding to the On-demand SSB SCell as applicable cells for measurement event A6.

[0143] As an example, if the measurement type is event-triggered reporting, the measurement event configuration (EventTriggerConfig) may include information identifying the On-demand SSB SCell (e.g., od-ssbConfig). Furthermore, if the measurement type is periodic reporting, the measurement event configuration (PeriodicalReportConfig) may include information identifying the On-demand SSB SCell (e.g., od-ssbConfig).

[0144] Alternatively, the terminal device 10 may be configured to report measurement reports of a measurement type that is periodic reporting, regardless of the information identifying the On-demand SSB SCell (e.g., od-ssbConfig) and its activation / deactivation status.

[0145] In method (1), the timing at which the activation or deactivation of On-demand SSB transmission is notified from the lower layer may be the same as in the first embodiment.

[0146] Next, an example of the procedure for implementing method (2) is shown below. For example, the terminal device 10 enables or disables the linked setting for the measurement identifier linked to the reporting setting (or measurement target) related to On-demand SSB SCell.

[0147] When RRC(L3) instructs a lower layer to activate On-demand SSB transmission, terminal device 10 activates the measurement identifier linked to the reporting settings (or measurement target) for the corresponding On-demand SSB SCell. Activating the measurement identifier means, in other words, that terminal device 10 begins evaluating the measurement type (typically event triggered) of the reporting settings linked to the measurement identifier. That is, terminal device 10 can perform the same measurement control and reporting control as before.

[0148] On the other hand, if the terminal device 10 is instructed by a lower layer to deactivate On-demand SSB transmission in RRC (L3), it disables the measurement identifier linked to the reporting setting (or measurement target) for the corresponding On-demand SSB SCell. Disabling the measurement identifier means, in other words, that the terminal device 10 does not start evaluating the measurement type (typically an event trigger) of the reporting setting linked to the measurement identifier. Alternatively, the terminal device 10 evaluates the measurement type (typically an event trigger) indicated in the reporting setting linked to the measurement identifier, but determines that the conditions for the entry of a measurement event are not always met.

[0149] In method (2), the timing at which the activation or deactivation of On-demand SSB transmission is notified from the lower layer may be the same as in the first embodiment.

[0150] Thus, according to the second embodiment, the base station device 20 can transmit information to the terminal device 10 to determine whether to start or stop the evaluation of measurement events corresponding to On-demand SSB in a secondary cell that supports On-demand SSB. Based on the information transmitted from the base station device 20, the terminal device 10 can determine the cell to which the evaluation of measurement events corresponding to On-demand SSB should be applied. Furthermore, based on the information transmitted from the base station device 20, the terminal device 10 can determine the start timing for the evaluation of measurement events corresponding to On-demand SSB transmission.

[0151] As a result, the event conditions are not met in the secondary cell, allowing the terminal device 10 to suppress the occurrence of measurement events. Therefore, unnecessary operation of the base station device 20 caused by the measurement event report of the terminal device 10 can be avoided, thereby improving the power saving efficiency of the base station device 20.

[0152] <Third Embodiment> The third embodiment is described below. Note that the configurations, functions, or procedures common to the first to third embodiments will not be explained. In other words, the following will mainly describe the differences from the first and second embodiments.

[0153] The first and second embodiments describe methods for suppressing measurement report messages when reusing conventional measurement events. The third embodiment, on the other hand, differs in that it suppresses measurement report messages by setting a measurement event that takes On-demand SSB SCell into consideration.

[0154] As measurement events that take On-demand SSB SCell into consideration, for example, there are methods such as (a) adding a new measurement type, or (b) adding a new measurement event.

[0155] An example of the procedure for implementing method (a) is shown below. For example, the base station device 20 sets a new measurement type in the reporting settings corresponding to On-demand SSB SCell, and the terminal device 10 performs measurement and reporting of On-demand SSB SCell based on the newly set measurement type.

[0156] For example, the base station device 20 sets "on-demand SSB transmission activation" as a new measurement type in the reporting settings, and links the reporting setting identifier corresponding to the reporting setting and the measurement target identifier corresponding to the measurement target including the On-demand SSB SCell using the measurement identifier.

[0157] For example, if the terminal device 10 has set "on-demand SSB transmission activation" as the measurement type in the reporting settings, and is notified from the lower layer (L1) that the On-demand SSB SCell in the measurement target linked to the reporting settings has been activated, the upper layer (RRC) may decide to trigger a measurement report.

[0158] If the terminal device 10 is notified of the activation of the On-demand SSB SCell, it may further decide to trigger a measurement report based on whether the requirements for measurement reporting of secondary cells are met. The requirements to be applied may be based on whether the terminal device 10 has measured the secondary cell for a predetermined time (e.g., 3 seconds or 5 DRX intervals) and considers it to be a known cell.

[0159] Alternatively, the terminal device 10 may, for example, determine to trigger a measurement report at the upper layer (RRC) if it is notified from the lower layer (L1) that the On-demand SSB SCell in the measurement target linked to the report setting has been deactivated, and the report setting has been set to On-demand SSB transmission deactivation as the measurement type in the report setting.

[0160] Furthermore, the terminal device 10 evaluates the measurement event, and if the L2 timer (for example, an On-demand SSB deactivation timer or a secondary cell deactivation timer) expires while the TTT is being measured, it may decide to trigger a measurement report at the timing of the deactivation of On-demand SSB transmission due to the expiration of the L2 timer.

[0161] In method (a), the timing at which the activation or deactivation of On-demand SSB transmission is notified from the lower layer may be the same as in the first embodiment.

[0162] Next, an example of the procedure for implementing method (b) is shown below. For example, terminal device 10 sets a new measurement event in the reporting settings for On-demand SSB SCell, and terminal device 10 performs measurement and reporting of On-demand SSB SCell based on the set new measurement event.

[0163] It is predicted that many of the unnecessary measurement reports from the terminal device 10 are due to the device mistakenly determining that the cell quality of the secondary cell to which On-demand SSB is transmitted has deteriorated. Therefore, unnecessary measurement reports can be suppressed by providing a measurement event that includes a measurement event (e.g., measurement event A1) that compares cell quality with a threshold.

[0164] Therefore, the base station device 20 sets a new measurement type in the reporting settings, for example, measurement event A1A3, which combines measurement event A1 and measurement event A3, and links the reporting setting identifier corresponding to the reporting setting and the measurement target identifier corresponding to the measurement target including On-demand SSB SCell using the measurement identifier.

[0165] For example, equations 5 and 6 show the event conditions for measurement event A1A3, and equations 7 and 8 show the event exit conditions for measurement event A1A3.

[0166] [Equation 5] Ms - Hys > Thresh

[0167] [Formula 6] Mn+Ofn+Ocn-Hys>Ms+Ofp+Ocp+Off

[0168] [Equation 7] Ms + Hys < Thresh

[0169] [Formula 8] Mn+Ofn+Ocn+Hys<Ms+Ofp+Ocp+Off

[0170] In other words, if measurement event A1A3 is set in the reporting settings, terminal device 10 starts measuring the On-demand SSB SCell at the measurement target linked to the reporting settings. If the cell quality (Ms) of the On-demand SSB SCell exceeds the threshold (Equation 5), and the cell quality (Mn) of the surrounding cells that are applicable cells exceeds the cell quality of the On-demand SSB SCell (Equation 6), it can be determined that the conditions for measurement event A1A3 have been met. (Note that determining whether or not a measurement event has occurred requires considering frequency offset, cell offset, hysteresis, and TTT, respectively, but this is obvious from the formulas, so the explanation is omitted.)

[0171] Furthermore, after determining that measurement events A1A3 have occurred in the reporting settings, the terminal device 10 may determine that the conditions for escaping measurement events A1A3 have been met if the cell quality (Ms) of the On-demand SSB SCell falls below the threshold (Equation 7), or if the cell quality (Mn) of the surrounding cells that are applicable cells falls below the cell quality of the On-demand SSB SCell (Equation 8). (Similar to the determination of the conditions for occurrence, determining whether or not a measurement event has been escaped requires considering frequency offset, cell offset, hysteresis, and TTT, respectively, but this is self-evident from the formulas and therefore the explanation is omitted.)

[0172] The base station device 20 may also set other new measurement types, such as measurement event A1A2, which is a combination of measurement event A1 and measurement event A2, or measurement event A1A5, which is a combination of measurement event A1 and measurement event A5 (details omitted).

[0173] As a variation of method (b), the terminal device 10 may transmit a measurement report when all of the multiple measurement events set by the base station device 20 in accordance with On-demand SSB SCell are met.

[0174] Specifically, the base station device 20 associates, for example, a first measurement event (e.g., measurement event A1) set in the first reporting setting and a second measurement event (e.g., measurement event A3) set in the second reporting setting with a first measurement target including an On-demand SSB SCell, and links them using different measurement identifiers. As explained using Figure 7, the base station device 20 links the first reporting setting identified by reportConfigId#0 and the second reporting setting identified by reportConfigId#1 with the measurement target including an On-demand SSB SCell identified by measObjectId#1, using measurement identifiers (measId#1, measId#2).

[0175] The terminal device 10 may send a measurement report message to the base station device 20 only if the measurement event conditions of the reporting settings (first reporting setting, second reporting setting) linked to the first measurement target are all met, when the measurement identifier relates to a first measurement target that includes On-demand SSB SCell. In other words, the terminal device 10 will not send a measurement report message unless the measurement event conditions of the reporting settings linked to the first measurement target are all met.

[0176] Furthermore, when the base station device 20 sets an On-demand SSB SCell for the terminal device 10, it does not need to set a reporting setting corresponding to the On-demand SSB SCell. Alternatively, when the On-demand SSB SCell is set by the base station device 20, the terminal device 10 does not need to store identifiers related to the measurement setting including the On-demand SSB SCell (measurement identifier, measurement target identifier, reporting setting identifier) ​​in the terminal device 10's internal variables.

[0177] Thus, according to the third embodiment, the base station device 20 can set new reporting settings (measurement type or measurement event) optimized for On-demand SSB in a secondary cell that supports On-demand SSB to the terminal device 10. Based on the reporting settings transmitted from the base station device 20, the terminal device 10 can perform an evaluation of the measurement event corresponding to On-demand SSB.

[0178] As a result, the conditions for a measurement event to occur are met at the appropriate time in the secondary cell, allowing the terminal device 10 to suppress the occurrence of unnecessary measurement events. Therefore, unnecessary operation of the base station device 20 caused by the measurement event report of the terminal device 10 can be avoided, improving the power saving efficiency of the base station device 20.

[0179] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its scope. The present invention can be modified or improved without departing from its spirit, and includes equivalents thereof. Furthermore, the embodiments described herein may be used individually, in combination, or switched between as needed during execution.

[0180] <Hardware Configuration of Each Device in Each Embodiment> Based on Figures 9 and 10, the hardware configuration of each device in the wireless communication system of each embodiment will be described.

[0181] Figure 9 shows an example of the hardware configuration of the terminal device 10. As shown in Figure 9, the terminal device 10 has, as hardware components, an RF (Radio Frequency) circuit 32 equipped with an antenna 31, a CPU (Central Processing Unit) 33, and a memory 34. Furthermore, the terminal device 10 may have a display device such as an LCD (Liquid Crystal Display) connected to the CPU 33. The memory 34 includes, for example, at least one of RAM (Random Access Memory) such as SDRAM (Synchronous Dynamic Random Access Memory), ROM (Read Only Memory), and flash memory, and stores programs, control information, and data signals.

[0182] The correspondence between the functional configuration of the terminal device 10 shown in Figure 3 and the hardware configuration of the terminal device 10 shown in Figure 9 will be explained. The transmitting / receiving antenna unit 19, the transmitting unit 17, and the receiving unit 15 are realized by, for example, an RF circuit 32, or an antenna 31 and an RF circuit 32. The control unit 13 and the processing unit 11 are realized by, for example, a CPU 33, memory 34, and a digital electronic circuit (not shown). Examples of digital electronic circuits include ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), and LSI (Large Scale Integration).

[0183] Figure 10 shows an example of the hardware configuration of a base station device 20. As shown in Figure 10, the base station device 20 has, as hardware components, an RF circuit 42 equipped with an antenna 41, a CPU 43, a DSP 44, a memory 45, and a network IF (Interface) 46. The CPU 43 is connected via a bus to enable input and output of various signals and data signals. The memory 45 includes, for example, RAM such as SDRAM, ROM, and flash memory, and stores programs, control information, and data signals.

[0184] The correspondence between the functional configuration of the base station device 20 shown in Figure 4 and the hardware configuration of the base station device 20 shown in Figure 10 will be explained. The transmitting / receiving antenna unit 29, the transmitting unit 27, and the receiving unit 25 are realized by, for example, an RF circuit 42, or an antenna 41 and an RF circuit 42. The control unit 23 and the processing unit 21 are realized by, for example, a CPU 43, a DSP 44, a memory 45, and a digital electronic circuit (not shown). Examples of digital electronic circuits include ASICs, FPGAs, and LSIs.

[0185] 1 Wireless Communication System 10 Terminal Devices 20A, 20B Base Station Devices 200, 201 Cell 30 Core Network 11, 21 Processing Units 13, 23 Control Units 15, 25 Receiving Units 17, 27 Transmitting Units 19, 29 Transmitting / Receiving Antenna Units 31, 41 Antennas 32, 42 RF Circuits 33, 43 CPU 34, 45 Memory 44 DSP 46 Network IF 111, 211 Wireless Resource Processing Units 113, 213 Measurement Processing Unit

Claims

1. A terminal device using a primary cell and a secondary cell, comprising: a receiving unit that receives from a base station device, a synchronization signal setting relating to a synchronization signal transmitted on demand to the secondary cell, a reporting setting relating to the reporting of the measurement results of the synchronization signal, and control information instructing the start or stop of the transmission of the synchronization signal; a control unit that, when the control information indicates the start of the transmission of the synchronization signal, performs an evaluation of the measurement event conditions for the secondary cell as instructed by the reporting setting, and does not perform an evaluation of the measurement event conditions when the control information indicates the stop of the transmission of the synchronization signal; and a transmitting unit that, when the conditions for fulfilling the measurement event conditions are met based on the measurement results of the secondary cell, transmits a measurement report message including the measurement results of the secondary cell to the base station device.

2. The terminal device according to claim 1, wherein when the control information notifies information indicating activation of the transmission of the synchronization signal, the first layer instructs a second layer lower than the first layer on which the control information is transmitted to start notification control of measurement results related to the synchronization signal, and when the control information notifies information indicating deactivation of the transmission of the synchronization signal, the first layer instructs the second layer to stop notification control of measurement results related to the synchronization signal.

3. The terminal device according to claim 1, wherein when the control information notifies information indicating activation of the transmission of the synchronization signal, the secondary cell identified in the synchronization signal setting is considered as the cell to which the measurement event is applied, and when the control information notifies information indicating deactivation of the transmission of the synchronization signal, the secondary cell identified in the synchronization signal setting is not considered as the cell to which the measurement event is applied.

4. The terminal device according to claim 3, wherein the synchronization signal setting is transmitted as part of the reporting setting, and the secondary cell of the measurement target corresponding to the reporting setting is considered to be the cell to which the measurement event is applied.

5. The terminal device according to claim 1, wherein the synchronization signal setting is included in the reporting setting or the measurement target indicating the frequency to be measured, and is linked by a measurement identifier indicating the correspondence between the reporting setting and the measurement target, and the control information notifies information indicating the activation of the transmission of the synchronization signal, the device starts evaluating the measurement event conditions of the secondary cell identified by the synchronization signal setting.

6. A base station device comprising: a transmitting unit that transmits to a terminal device a synchronization signal setting relating to a synchronization signal to be transmitted on demand to the secondary cell, a reporting setting relating to the reporting of the measurement results of the synchronization signal, and control information that instructs the terminal device to start or stop transmitting the synchronization signal; a control unit that sets information in the control information to instruct the terminal device to start transmitting the synchronization signal in order to perform an evaluation of the measurement event conditions for the secondary cell as instructed by the reporting setting, and sets information in the control information to instruct the terminal device to stop transmitting the synchronization signal in order to prevent the terminal device from performing an evaluation of the measurement event conditions for the secondary cell as instructed by the reporting setting; and a receiving unit that receives a measurement report message transmitted from the terminal device, including the measurement results of the secondary cell, when the conditions for fulfilling the measurement event conditions are met based on the measurement results of the secondary cell.

7. The base station device according to claim 6, wherein the control information includes either information indicating activation of the transmission of the synchronization signal, which causes the terminal device to determine that the secondary cell is a cell to which a measurement event is applied, or information indicating deactivation of the transmission of the synchronization signal, which causes the terminal device to determine that the secondary cell is not a cell to which a measurement event is applied, and transmits this information.

8. The base station device according to claim 6, wherein the synchronization signal setting is set to include the reporting setting or the measurement target indicating the frequency to be measured, the reporting setting and the measurement target are linked using a measurement identifier, and information indicating activation of the transmission of the synchronization signal is transmitted to the terminal device, thereby instructing the terminal device to start evaluating the measurement event conditions of the secondary cell corresponding to the linked measurement target.

9. A method for controlling a terminal device using a primary cell and a secondary cell, comprising: receiving means for receiving synchronization signal settings relating to synchronization signals transmitted on demand to the secondary cell from a base station device, reporting settings relating to reporting the measurement results of the synchronization signals, and control information instructing the start or stop of the transmission of the synchronization signals; control means for performing an evaluation of the measurement event conditions for the secondary cell instructed by the reporting settings when the control information indicates the start of the transmission of the synchronization signals, and not performing an evaluation of the measurement event conditions when the control information indicates the stop of the transmission of the synchronization signals; and transmitting means for transmitting a measurement report message including the measurement results of the secondary cell to the base station device when the conditions for fulfilling the measurement event conditions are met based on the measurement results of the secondary cell.

10. A method for controlling a base station device, comprising: a transmitting means that transmits to a terminal device a synchronization signal setting relating to a synchronization signal to be transmitted on demand to the secondary cell, a reporting setting relating to the reporting of the measurement results of the synchronization signal, and control information that instructs the terminal device to start or stop transmitting the synchronization signal; a control means that sets information in the control information to instruct the terminal device to start transmitting the synchronization signal in order to perform an evaluation of the measurement event conditions for the secondary cell as instructed by the reporting setting, and sets information in the control information to instruct the terminal device to stop transmitting the synchronization signal in order to prevent the evaluation of the measurement event conditions for the secondary cell as instructed by the reporting setting; and a receiving means that receives a measurement report message transmitted from the terminal device, including the measurement results of the secondary cell, when the conditions for fulfilling the measurement event conditions are met based on the measurement results of the secondary cell.

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