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

Abstract

The present invention improves efficiency of power saving related to wireless communication between a terminal device and a base station device. The terminal device comprises a control unit, a transmission unit, and a reception unit. The reception unit receives, from a base station device, first information for setting a time window for measuring a synchronization signal / physical broadcast channel block, which is a first SSB temporarily transmitted on a secondary cell, and second information for giving an instruction to activate the first SSB. The control unit applies a configuration of the time window set according to the first information, the configuration corresponding to third information included in the second information. The transmission unit transmits, to the base station device, a result of measuring the first SSB according to the configuration of the time window.

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)), the support of 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 formulated.

[0004] In the international standardization project, the 3rd Generation Partnership Project (3GPP: 3rd Generation Partnership Project (registered trademark)), the extended technologies of the above communication standard are still continuously studied and standardized.

[0005] In 3GPP, in order to reduce the power consumption on the network side (that is, base station devices and core network devices), 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 On-demand SSB, which is transmitted as needed, 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 the problem of not obtaining accurate measurement results. Non-patent document 2 discloses the problems with measurement methods when applying such On-demand SSB to secondary cells, but it does not mention any specific solutions for this.

[0009] One aspect of the present invention is to improve the efficiency of power saving in wireless communication between terminal equipment and base station equipment when applying network power reduction technology that appropriately transmits SSB.

[0010] A terminal device according to one aspect of the present invention includes a receiving unit that receives first information for setting a time window for measuring a synchronization signal / physical broadcast channel block, which is a first SSB temporarily transmitted to a secondary cell from a base station device, and second information instructing the activation of the first SSB, a control unit that applies the setting of the time window set according to the first information, which corresponds to third information included in the second information, and a transmitting unit that transmits the measurement result of the first SSB, measured according to the setting of the time window, to the base station device.

[0011] A base station device according to one aspect of the present invention includes a transmitting unit that transmits to a terminal device first information for setting a time window for measuring a synchronization signal / physical broadcast channel block, which is a first SSB temporarily transmitted to a secondary cell, and second information for instructing the activation of the first SSB; a control unit that includes a third information corresponding to the time window setting in the second information in order to apply the time window setting according to the first information to the terminal device; and a receiving unit that receives the measurement result of the first SSB measured by the terminal device according to the time window setting.

[0012] According to the above-described embodiment, the objective 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.

[0013] 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 setting parameters of an SMTC corresponding to On-demand SSB. This figure shows an example of control information that instructs the activation or deactivation of On-demand SSB. This figure shows an example of an On-demand SSB measurement method. This figure shows another example of an On-demand SSB measurement method. This figure shows another example of an On-demand SSB measurement method. This figure shows an example of a method for determining the type of secondary cell. This figure shows an example of the relationship between conventional SMTC and SSB. 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] <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 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The technology of aggregating cells with multiple 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).

[0026] On-demand SSB is 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.

[0027] Figure 2 is an example of a cell configuration when applying On-demand SSB. In Figure 2, cell 200 is the primary cell when performing carrier aggregation, and cell 201 is a secondary cell (On-demand SSB SCell) that supports On-demand SSB.

[0028] 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.

[0029] 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).

[0030] 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). Note that the sleep state may be described as the first state and the non-sleep state as the second state.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] RRC messages are transmitted as RRC PDUs (Protocol Data Units) and are 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).

[0037] 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 plus header information defined, for example, in 8-bit units, and a MAC PDU contains one or more MAC subPDUs.

[0038] 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.

[0039] <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.

[0040] 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 layer, for example.

[0041] 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 events related to handover, and performs a series of processes related to handover.

[0042] 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, and so on.

[0043] 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. Further, 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.

[0044] 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.

[0045] 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 the 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.

[0046] 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 operations 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.

[0047] <Base Station Device>FIG. 4 is a diagram showing an example of the functional configuration of the base station device 20 according to the embodiment. As shown in FIG. 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 transceiver 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 FIG. 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 that realize other functions.

[0048] 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 processing related to, for example, the radio resource control layer, the packet data convergence protocol layer, the radio link control layer, and the media access control layer.

[0049] The radio resource processing unit 211 generates, for example, downlink data, RRC messages, and MAC control elements arranged on 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 on the physical downlink control channel PDCCCH and outputs them to the transmitting unit 27. Furthermore, 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 starts and stops transmission and reception processing, starts UL synchronization procedures (random access procedures), updates system information, starts and stops on-demand SSB transmission, adjusts the transmission angle of beams, generates parameters related to on-demand SSB transmission procedures, generates parameters related to on-demand SSB measurement procedures, etc.

[0050] 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 on the parameters necessary for receiving On-demand SSB.

[0051] 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 On-demand SSB transmission based on judgment information regarding On-demand SSB transmission from the measurement processing unit 213.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] <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.

[0057] 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).

[0058] 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.

[0059] 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.

[0060] 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.

[0061] <On-demand SSB> On-demand SSB is one of the power-saving technologies applied to the base station equipment 20, and is a method of transmitting secondary cell SSB as needed, rather than periodically transmitting it during carrier aggregation. The signal format and multiplexing method of On-demand SSB may 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. Also, On-demand SSB is an example of the first type of SSB.

[0062] 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.

[0063] 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 SSBs with a longer period than conventional ones also transmits On-demand SSBs (with a shorter period than conventional SSBs) (second case).

[0064] <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.

[0065] 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.

[0066] Figure 12 shows an example of the relationship between conventional SMTC and SSB. In Figure 12, the SMTC periodicity is set to, for example, 40 milliseconds (40ms). The base station device 20 sets information for the terminal device 10 indicating an offset value (for example, the distance from the beginning of the SFN (system frame number) indicated by subframes) to adjust the SMTC start timing and the SMTC period. 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.

[0067] In Figure 12, the base station device 20 sets the SMTC period (P100) at a certain frequency to be measured to 40 ms. The terminal device 10 performs SSB detection and measurement 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 repeats every period P100. That is, the SMTC repeats 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).

[0068] 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.

[0069] <First Embodiment> Figure 5 is an example of a sequence diagram showing the measurement procedure for On-demand SSB of the terminal device 10 and base station device 20 according to the first embodiment.

[0070] 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 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. RRC messages include, for example, individual RRC messages, RRCReconfiguration messages, and RRCSetup messages. In Figure 5, an example of an RRC message is explained as an RRCReconfiguration message.

[0071] 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 pending downlink buffer exceeds a predetermined threshold). Similarly, when it determines that it is not necessary (for example, when the amount of pending downlink buffer falls below a predetermined threshold), it stops transmitting On-Demand SSB.

[0072] The base station device 20 may activate the secondary cell (On-demand SSB SCell) 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.

[0073] In Figure 5, in step S100, the base station device 20 notifies the base station device 20 of an instruction to add an On-demand SSB-supporting secondary cell (On-demand SSB SCell) 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 acquires one or more On-demand SSB configuration information and adds the specified secondary cell to start the carrier aggregation transmission and reception procedure. Furthermore, when the terminal device 10 has completed the configuration procedure related to the settings received in step S100, it generates an RRC message (RRCReconfigurationComplete) indicating the completion of the configuration and sends it to the base station device 20 (step S101). Note that the On-demand SSB configuration information is an example of the first type of information. Alternatively, the On-demand SSB configuration information may be described as information that sets a time window for measuring the synchronization signal / physical broadcast channel block, which is the first SSB temporarily transmitted to the secondary cell.

[0074] Figure 6 shows an example of SMTC setting parameters (SMTC settings) related to SSB measurement among the On-demand SSB configuration information. On-demand SSB configuration information may be included in the secondary cell configuration (SCell configuration) or in the measurement object corresponding to the frequency of the secondary cell. Alternatively, the SSB frequency information (absoluteFrequencySSB) and physical cell ID (PCI) may be included in the secondary cell configuration, and the SMTC settings may be included in the measurement object.

[0075] Furthermore, as shown in Figure 6, 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.

[0076] In the example in Figure 6, index information: 0 corresponds to a combination of period: 10 ms, offset value: 0 ms, and SMTC window interval: 1 subframe. Similarly, index information: 1 corresponds to a combination of period: 20 ms, offset value: 5 ms, and SMTC window interval: 2 subframes, and index information: N corresponds to a combination of period: 80 ms, offset value: 20 ms, and SMTC window interval: 2 subframes. The base station device 20 specifies one of {5, 10, 20, 40, 80, 160} as the SMTC period (ms), one of the values ​​from 0 to (period - 1) as the offset value (ms) (for example, the range of values ​​when the period is 160 ms is 0 to 159), and one of {1, 2, 3, 4, 5} as the interval (subframe).

[0077] Furthermore, the base station device 20 may not explicitly notify the index information (SMTC index) and may instead assign index numbers in descending order to the 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".

[0078] Returning to Figure 5, in step S102, the terminal device 10 transmits information from the terminal device 10 (UE information) to the base station device 20. The information from 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.

[0079] 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.

[0080] 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.

[0081] The information instructing the activation of the On-demand SSB in step S104 may be Downlink Control Information (DCI) included in the PDCCH, MAC CE, or RRC message. When MAC CE is used, it may be transmitted simultaneously with SCell Activation / Deactivation MAC CE. Note that the information instructing the activation of the On-demand SSB is an example of the second type of information.

[0082] The base station device 20 may transmit the SMTC index information shown in Figure 6 as information instructing the activation of the 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 SCell). More specifically, the terminal device 10 derives the transmission timing of the 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 the On-demand SSB within the interval of the SMTC window. The base station device 20 instructs the terminal device 10 to use the index information to specify the SMTC corresponding to the transmission period of the On-demand SSB to be transmitted to the secondary cell. Note that the SMTC index information is an example of the third type of information. Note that the SMTC index information is just one example; other information that instructs the activation of the corresponding SMTC may be used.

[0083] 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.

[0084] Figure 7 shows an example of a MAC CE format used to instruct the activation or deactivation of an On-Demand SSB.

[0085] In Figure 7, each column consists of 8 bits (1 octet), indicating that the format is composed of a 3-octet bit sequence. In the figure, "R" represents a reserved bit, indicating an unused bit. The unused bit R is set to the value "0". The "Ci" (i = 1 to 7) field in the first octet column is an information bit indicating the activation or deactivation of a secondary cell, and corresponds to the index number (SCell index) of the secondary cell set in the terminal device 10. If the "Ci" field is "1", it indicates that the corresponding secondary cell (SCell index i) is activated. On the other hand, if the "Ci" field is "0", it indicates that the corresponding secondary cell (SCell index i) is deactivated. For example, if the "C2" field is "1", it indicates that the secondary cell with "index number: 2" (SCell index 2) set in the terminal device 10 is activated.

[0086] The "Wi" (i=1-7) fields in the second and third octet columns are information bits indicating the activation or deactivation of the secondary cell's On-demand SSB, and are encoded in accordance with the secondary cell's index number (SCell index) set in the terminal device 10. Furthermore, the information bits indicated by "Wi" correspond to the index number of the SMTPC setting (i.e., On-demand SSB setting) applied to the corresponding secondary cell.

[0087] If the information bit in the "Wi" field is anything other than "0", it indicates that On-demand SSB is activated in the corresponding secondary cell and that the SMTPC setting corresponding to the specified index number is applied. On the other hand, if the information bit in the "Wi" field is "0", it indicates that SMTPC does not need to be applied (i.e., On-demand SSB is deactivated (transmission is stopped) in the corresponding secondary cell). For example, if the "W1" field shows "3", it indicates that On-demand SSB corresponding to the SMTPC setting of "Index Number: 3" (SMTC index 3) is activated (transmitted) in the secondary cell of "Index Number: 1" (SCell index 1) set in the terminal device 10.

[0088] Figure 7 shows an example of encoding using 2 bits for each "Wi" field (i.e., indicating that the SMTC setting to be set for each secondary cell is 1 to 3), but it may be modified to assign a different number of bits depending on the maximum number of SMTC settings (not shown).

[0089] Furthermore, if a conventional SMTC setting (first SMTC setting) is set for a secondary cell that supports On-demand SSB (On-demand SSB SCell), the terminal device 10 may ignore the first SMTC setting and not perform SSB measurement of the secondary cell based on the first SMTC setting. Alternatively, if the first SMTC setting is set for an On-demand SSB SCell, the terminal device 10 may consider the first SMTC setting as part of the SMTC setting corresponding to On-demand SSB (second SMTC setting). For example, the terminal device 10 may consider the first SMTC setting as "index number: 0" (SMTC index 0) of the second SMTC setting. In this case, the index number of the second SMTC setting starts from "1" (SMTC index 1).

[0090] The relationship between SMTC and On-demand SSB transmission timing in the first embodiment will be explained using Figures 8 and 9. Figure 8 is a diagram showing an example of an On-demand SSB measurement method. Figure 9 is a diagram showing another example of an On-demand SSB measurement method. In both Figures 8 and 9, the base station device 20 notifies the terminal device 10 of multiple SMTC settings applied to the secondary cell frequency, as shown in Figure 6. Hereafter, the case in which SSB is not transmitted periodically in the secondary cell, and On-demand SSB is transmitted as needed, will be referred to as the first case.

[0091] The time T10 in Figure 8 indicates the timing when the base station device 20 sends a signal to the terminal device 10 instructing it to activate On-demand SSB (SSB burst) transmission (SSB activation). At this time, the base station device 20 includes an index number instructing the SMTC setting used for detecting and measuring On-demand SSB in the signal (Figure 8 shows an example where index number: 0 is instructed). When the terminal device 10 receives the signal instructing it to activate On-demand SSB transmission at time T10, it obtains the index number of the secondary cell where On-demand SSB is activated (SCell index) and the index number of the SMTC setting to be applied (SMTC index) from the signal. In other words, the terminal device 10 determines the measurement timing (SMTC) for On-demand SSB based on the information indicated by the signal, and performs detection and measurement of On-demand SSB based on the SMTC.

[0092] Time T11 indicates the start timing of the SMTC window determined by the terminal device 10, taking into account the SMTC offset (not shown). The terminal device 10 performs On-demand SSB detection and measurement during the SMTC interval (duration). The SMTC repeats every period P10 (10 ms in Figure 8). That is, the SMTC repeats at time T12, which is period P10 after time T11, and again at time T13, which is period P10 after time T12 (the same applies hereafter).

[0093] Time T14 indicates the time when the terminal device 10 stops applying the SMTC window for detecting and measuring activated On-demand SSB. Alternatively, it indicates the time when the base station device 20 stops transmitting activated On-demand SSB. Time T14 may be a predetermined time elapsed from the time T11 when the SMTC window started, or it may be a time determined by the maximum number of repetitions of the SMTC window. Here, the predetermined time or the maximum number of repetitions may be a fixed value defined in advance, a value specified by the base station device 20 as part of the SMTC setting, or a different value for each SMTC (SMTC index).

[0094] Time T15 indicates the timing when the base station device 20 sends a signal to the terminal device 10 instructing it to deactivate On-demand SSB transmission (SSB deactivation). Based on the information indicated by the signal, the terminal device 10 decides to stop applying the SMTC settings corresponding to On-demand SSB and simultaneously stops measuring On-demand SSB. The terminal device 10 may also stop applying the SMTC window if it receives a deactivation signal from the base station device 20. In this case, the deactivation signal will be sent at a time earlier than time T14. The base station device 20 may not send a deactivation signal after time T14 if it can be considered that the terminal device 10 has decided to stop applying the SMTC settings.

[0095] The time T20 in Figure 9 indicates the timing when the base station device 20 sends a signal to the terminal device 10 instructing it to activate On-demand SSB (SSB burst) transmission (SSB activation). At this time, the base station device 20 also includes an index number instructing the SMTC setting used for detecting and measuring On-demand SSB in the signal (Figure 9 shows an example where index number 1 is instructed). When the terminal device 10 receives the signal instructing it to activate On-demand SSB transmission at time T20, it obtains the SCell index of the secondary cell where On-demand SSB is activated and the SMTC index of the SMTC setting to be applied from the signal. In other words, the terminal device 10 determines the measurement timing (SMTC) for the On-demand SSB based on the information indicated by the signal, and performs detection and measurement of the On-demand SSB.

[0096] Time T21 indicates the start timing of the SMTC window determined by the terminal device 10, taking into account the SMTC offset (not shown). The terminal device 10 performs On-demand SSB detection and measurement during the SMTC interval (duration). The SMTC repeats every period P20 (20 ms in Figure 9). That is, the SMTC repeats at time T22, which is period P20 after time T21, and again at time T23, which is period P20 after time T22 (the same applies hereafter).

[0097] The times T24 and T25 correspond to the times T14 and T15 in Figure 8, so we will omit the details. Specifically, time T24 indicates the time when the application of the SMTC window for detecting and measuring activated On-demand SSB is stopped. Time T25 indicates the timing when the base station device 20 sends a signal to the terminal device 10 instructing it to deactivate On-demand SSB transmission (SSB deactivation).

[0098] Thus, the terminal device 10 can perform On-demand SSB measurements only in sections where On-demand SSB is activated based on instructions from the base station device 20 (sections where On-demand SSB is transmitted). In other words, the terminal device 10 can perform On-demand SSB measurements only in sections where SMTPC is enabled.

[0099] When measurements are performed only in sections where On-demand SSB is activated, the terminal device 10 must indicate in the measurement report message whether or not the measurement was performed only in sections where On-demand SSB was activated. This is because the terminal device 10 reports the measurement results of all cells in the service area, including secondary cells, to the base station device 20. Therefore, the base station device 20 needs to determine whether the measurement results of the secondary cells being reported indicate that On-demand SSB was not measured, or that the reception quality of On-demand SSB is poor.

[0100] The terminal device 10 may add an identifier to the measurement results reported to the base station device 20 after the On-demand SSB is activated, indicating that the measurement was taken during the On-demand SSB activation period. The identifier may be a single-bit identifier or a multi-bit identifier. Based on the presence or absence of the identifier, the base station device 20 determines whether the reported secondary cell measurement results were taken during the On-demand SSB activation period.

[0101] Furthermore, in order to ensure the accuracy of the measurement results, the terminal device 10 may only enable the L3 filtering coefficient (filter coefficient f) used for smoothing (filtering) the measurement results during the section in which On-demand SSB is activated. That is, during the section in which On-demand SSB is activated, the terminal device 10 calculates the measured value by applying the L3 filtering coefficient to the measured result and past measurement results. On the other hand, during the section in which On-demand SSB is deactivated, the L3 filtering coefficient is not applied to the measured result (L3 filtering is not performed).

[0102] Furthermore, the terminal device 10 may reset the measurement results based on L3 filtering when the On-demand SSB is activated and when it is deactivated. Alternatively, the terminal device 10 may reset the measurement results based on L3 filtering when the timer, which is timed when the On-demand SSB is activated, expires.

[0103] Thus, according to the first embodiment, the base station device 20 can notify the secondary cell supporting On-demand SSB of the activation of On-demand SSB, and at the same time notify the terminal device 10 of a measurement timing suitable for the period of the transmitted On-demand SSB. The terminal device 10 can detect and measure On-demand SSB by determining a measurement timing suitable for the period of the transmitted On-demand SSB based on the instructions from the base station device 20. As a result, the power saving efficiency of the base station device 20 can be improved.

[0104] <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.

[0105] Using Figure 10, the relationship between the SMTC related to the second embodiment, the conventional SSB transmitted periodically, and the transmission timing of On-demand SSB will be explained. Figure 10 is a diagram showing another example of the On-demand SSB measurement method. In Figure 10, the base station device 20 notifies the terminal device 10 of multiple SMTC settings applied to the secondary cell frequency, as shown in Figure 6.

[0106] The base station device 20 in Figure 10 supports both periodically transmitted SSB (i.e., not On-demand SSB) and On-demand SSB. Hereafter, in the case where, in addition to periodically transmitted SSB (first SSB), On-demand SSB (second SSB) is transmitted as appropriate in the secondary cell, this will be referred to as the second case. The period of conventional SSB (Periodicity 2) is longer than the period of On-demand SSB (Periodicity 1), and in the example of Figure 10, Periodicity 2 is 40 ms and Periodicity 1 is 10 ms. Furthermore, the base station device 20 notifies the terminal device 10 that the SMTC setting (first SMTC setting) for periodically detecting and measuring conventional SSB is included in the secondary cell setting. When a secondary cell is added, the terminal device 10 periodically performs conventional SSB detection and measurement based on the first SMTC setting.

[0107] Time T30 indicates the start timing of the SMTC (first SMTC window) for detecting and measuring the periodic SSB (first SSB) transmitted by the base station device 20 to the terminal device 10. Time T30 is determined considering the set SMTC offset (not shown). The terminal device 10 detects and measures the first SSB from time T30 until the interval (duration) of the first SMTC window has elapsed. The SMTC (first SMTC window) is applied repeatedly every period P30 (40 ms in Figure 10). That is, the next SMTC is applied at time T31, which is period P30 after time T30 (the same applies hereafter).

[0108] Time T32 indicates the timing when the base station device 20 transmits a signal (SSB activation) instructing the activation of On-demand SSB (second SSB) transmission. At this time, the base station device 20 also includes an index number instructing the SMTC setting (second SMTC setting) used for detecting and measuring On-demand SSB in the signal (Figure 10 shows an example where index number: 0 is instructed). When the terminal device 10 receives a signal instructing the activation of On-demand SSB transmission at time T32, it obtains the index number (SCell index) of the secondary cell where On-demand SSB is activated and the index number (SMTC index) of the second SMTC setting to be applied from the signal. In other words, the terminal device 10 determines the measurement timing for On-demand SSB (second SMTC window) based on the information indicated by the signal, and performs detection and measurement of On-demand SSB.

[0109] Time T33 indicates the start timing of the second SMTC window, determined by the terminal device 10 considering the corresponding SMTC offset (not shown). The terminal device 10 performs detection and measurement of the second SSB during the interval (duration) of the second SMTC window. The SMTC (second SMTC window) is applied repeatedly every period P31 (10 ms in Figure 10). That is, the next SMTC is applied at time T34, which is period P31 after time T33.

[0110] Time T35 indicates the time when the terminal device 10 stops applying the second SMTC window. Alternatively, it indicates the time when the base station device 20 stops transmitting activated On-demand SSB. Time T35 may be a predetermined time elapsed from the time T33 when the second SMTC window started, or it may be a time determined by the maximum number of repetitions of the second SMTC window. Here, the predetermined time or the maximum number of repetitions may be a fixed value defined in advance, a value specified by the base station device 20 as part of the second SMTC setting, or a different value for each SMTC (SMTC index).

[0111] Since time T36 corresponds to time T15 in Figure 8, the details are omitted. In other words, time T36 indicates the timing when the base station device 20 sends a signal to the terminal device 10 instructing it to deactivate On-demand SSB transmission (SSB deactivation).

[0112] Thus, the terminal device 10 can perform On-demand SSB measurements in sections where On-demand SSB (second SSB) is activated (sections where On-demand SSB is transmitted) in addition to periodic SSB (first SSB) based on instructions from the base station device 20. In other words, the terminal device 10 can perform On-demand SSB measurements in sections where SMTPC corresponding to the second SSB is enabled, in addition to periodic SSB (first SSB).

[0113] Furthermore, if the physical cell IDs (PCI) of the first SSB and the second SSB are different, the terminal device 10 may, in order to ensure accurate measurement results, only enable the L3 filtering coefficient (filter coefficient f) used for smoothing (filtering) the measurement results of the second SSB during the interval in which the On-demand SSB (second SSB) is activated. That is, the terminal device 10 calculates the measured value by applying the L3 filtering coefficient of the second SSB to the results measured during the interval in which the On-demand SSB is activated and to past measurement results. On the other hand, during the interval in which the On-demand SSB is deactivated, the L3 filtering coefficient of the second SSB is not applied to the measured results (L3 filtering is not performed).

[0114] Furthermore, the terminal device 10 may reset the measurement results based on the L3 filtering of the second SSB when the On-demand SSB is activated and when it is deactivated. Alternatively, the terminal device 10 may reset the measurement results based on the L3 filtering of the second SSB when the timer, which is timed when the On-demand SSB is activated, expires.

[0115] Furthermore, if the physical cell ID (PCI) of the first SSB and the second SSB are the same, the terminal device 10 may consider the results measured in the section in which the On-demand SSB (second SSB) is activated as additional measurement results for the first SSB and perform L3 filtering of the first SSB.

[0116] Thus, when the base station device 20 transmits SSB (first SSB) periodically in the secondary cell as in the conventional case (second case), the terminal device 10 requires different control than when it does not transmit SSB periodically (first case). Therefore, the following describes how the terminal device 10 can identify whether it is the first case or the second case when setting up (adding) a secondary cell.

[0117] Figure 11 shows an example of a method for determining (identifying, distinguishing) the type of secondary cell (SCell type) based on secondary cell information set from the base station device 20 to the terminal device 10.

[0118] absoluteFrequencySSB is information indicating the frequency at which periodic SSB (first SSB) is transmitted in the corresponding cell. absoluteFrequencySSB2 is information indicating the frequency at which on-demand SSB (second SSB) is transmitted in the corresponding cell. SMTC1 is SMTC setting information corresponding to the first SSB, and SMTC2 is SMTC setting information corresponding to the second SSB. SMTC1 may also be the SMTC of a secondary cell (SCell SMTC). In the diagram, "None" indicates that the parameter is not set (omitted), and "Configured" means that the parameter is set by the base station device 20. Furthermore, the base station device 20 guarantees that SMTC1 has the same or a larger value (i.e., longer period) than SMTC2.

[0119] As shown in Figure 11, a secondary cell in which absoluteFrequencySSB is not set and SMTC1 is not set is an SSB-less SCell. An SSB-less SCell is a secondary cell in which conventional SSB is not transmitted. Terminal device 10 considers a secondary cell in which absoluteFrequencySSB and SMTC1 are not set to be an SSB-less SCell. In this case, terminal device 10 does not need to use absoluteFrequencySSB2 and SMTC2 to determine the type of secondary cell.

[0120] Furthermore, a secondary cell in which absoluteFrequencySSB is set, absoluteFrequencySSB2 and SMTC1 are not set, and SMTC2 is set is an On-demand SSB SCell in the first case. Here, absoluteFrequencySSB may be considered as the frequency in which the second SSB is transmitted. SMTC1 is the SMTC (SCell SMTC) of the secondary cell. The terminal device 10 considers a secondary cell in which absoluteFrequencySSB is set, SMTC1 is not set, and SMTC2 is set to be an On-demand SSB SCell in the first case and performs control related to SSB measurement.

[0121] Furthermore, the base station device 20 may set absoluteFrequencySSB2 instead of absoluteFrequencySSB to indicate the On-demand SSB SCell in the first case. In other words, the base station device 20 may leave absoluteFrequencySSB and SMTC1 unset and set absoluteFrequencySSB2 and SMTC2.

[0122] Furthermore, a secondary cell in which absoluteFrequencySSB is set and SMTC1 and SMTC2 are set is an On-demand SSB SCell in the second case. Here, absoluteFrequencySSB is the frequency at which the first SSB is transmitted. SMTC1 is the SMTC (SCell SMTC) of the secondary cell for the first SSB. Note that if the frequencies of the first SSB and the second SSB are different, absoluteFrequencySSB2 may indicate the frequency at which the second SSB is transmitted. In other words, absoluteFrequencySSB2 is optional information. The terminal device 10 considers a secondary cell in which absoluteFrequencySSB is set and SMTC1 and SMTC2 are set to be an On-demand SSB SCell in the second case and performs control related to SSB measurement.

[0123] By configuring the system in this way, the base station device 20 can implicitly notify the terminal device 10 of the type of secondary cell based on the parameter setting method. The terminal device 10 can determine the type of secondary cell from the set parameters and can then perform appropriate control (e.g., SSB measurement control) based on the type of secondary cell.

[0124] Thus, according to the second embodiment, in a secondary cell that supports both conventional periodic SSB and On-demand SSB, the base station device 20 can notify the terminal device 10 of the activation of On-demand SSB and simultaneously notify the terminal device 10 of a measurement timing suitable for the period of the transmitted On-demand SSB. The terminal device 10 can detect and measure On-demand SSB by determining a measurement timing suitable for the period of the transmitted On-demand SSB based on the instructions from the base station device 20. As a result, the power saving efficiency of the base station device 20 can be improved.

[0125] 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, each aspect / embodiment described herein may be used individually, in combination, or switched between during implementation. For example, the terminal device 10 may detect beam faults based on On-demand SSB based on activated SMTC settings.

[0126] <Hardware Configuration of Each Device in Each Embodiment> Based on Figures 13 and 14, the hardware configuration of each device in the wireless communication system of each embodiment will be described.

[0127] Figure 13 shows an example of the hardware configuration of the terminal device 10. As shown in Figure 13, 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.

[0128] 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 13 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).

[0129] Figure 14 shows an example of the hardware configuration of a base station device 20. As shown in Figure 14, 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.

[0130] 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 14 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.

[0131] 1 Wireless Communication System 10 Terminal Devices 20, 20A, 20B Base Station Devices 200, 201 Cells 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 Units

Claims

1. A terminal device comprising: a receiving unit that receives first information for setting a time window for measuring a synchronization signal / physical broadcast channel block, which is a first SSB (Synchronization Signal / PBCH block) temporarily transmitted from a base station device to a secondary cell, and second information instructing the activation of the first SSB; a control unit that applies the setting of the time window set according to the first information, which corresponds to third information included in the second information; and a transmitting unit that transmits the measurement result of the first SSB, measured according to the setting of the time window, to the base station device.

2. The terminal device according to claim 1, which sets and reports an identifier indicating that the first SSB has been measured according to the setting of the time window.

3. The terminal device according to claim 1, wherein the second information is a MAC CE (Media Access Control Control Element), the third information indicates the corresponding secondary cell by the position of the field, and the encoded information bits of the field indicate the setting of the time window to be applied.

4. The terminal device according to claim 1, which determines the type of secondary cell based on the first information and a fourth information specifying the frequency of a second SSB periodically transmitted to the secondary cell, and performs a measurement based on the type of secondary cell.

5. The terminal device according to claim 1, wherein when the first SSB is activated, a filter coefficient is applied to the measurement result of the first SSB, and when the first SSB is deactivated, the filter coefficient is not applied to the measurement result of the first SSB.

6. A base station device comprising: a transmitting unit that transmits to a terminal device first information for setting a time window for measuring a synchronization signal / physical broadcast channel block, which is a first SSB (Synchronization Signal / PBCH block) temporarily transmitted to a secondary cell, and second information instructing the activation of the first SSB; a control unit that includes third information corresponding to the time window setting in the second information in order to apply the time window setting according to the first information to the terminal device; and a receiving unit that receives the measurement result of the first SSB measured by the terminal device according to the time window setting.

7. The base station apparatus according to claim 6, wherein the second information is a MAC CE (Media Access Control Control Element), the third information indicates the corresponding secondary cell by the position of the field, and the encoded information bits of the field indicate the setting of the time window to be applied.

8. The base station device according to claim 6, which transmits the first information and a fourth information specifying the frequency of a second SSB periodically transmitted to the secondary cell to the terminal device in order to perform the measurement of the secondary cell.

9. A control method for a terminal device, comprising: first information for setting a time window for measuring a synchronization signal / physical broadcast channel block, which is a first SSB (Synchronization Signal / PBCH block) temporarily transmitted from a base station device to a secondary cell; second information for instructing the activation of the first SSB; control means for applying the setting of the time window, which is set according to the first information and corresponds to third information included in the second information; and transmission means for transmitting the measurement result of the first SSB, measured according to the setting of the time window, to the base station device.

10. A control method for a base station device, comprising: a transmitting means for transmitting to a terminal device first information for setting a time window for measuring a synchronization signal / physical broadcast channel block, which is a first SSB (Synchronization Signal / PBCH block) temporarily transmitted to a secondary cell, and second information for instructing the activation of the first SSB; a controlling means for including a third information corresponding to the time window setting in the second information in order to apply the time window setting according to the first information to the terminal device; and a receiving means for receiving the measurement result of the first SSB measured by the terminal device according to the time window setting.

Images