Terminal device, base station device, control method, and program for on-demand ssb in secondary cell for efficient carrier aggregation

Abstract

A terminal device is a terminal device that complies with a cellular communication standard of the Third Generation Partnership Project (3GPP), wherein the terminal device receives, from a base station device that provides a primary cell of carrier aggregation, second setting information that is different from first setting information in a case where transmission of a synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) in a secondary cell is not suppressed, in a case where transmission of at least a part of the SSB is not performed, performs measurement setting of the SSB in the secondary cell based on the second setting information, and measures the SSB transmitted in the secondary cell using the measurement setting.

Description

Technical Field

[0001] This invention relates to the application technology of On-demand SSB in cellular communication systems. Background Technology

[0002] In the 3rd Generation Partnership Project (3GPP (registered trademark)), suppressing network power consumption is being discussed as an important issue. Within this discussion, the implementation of on-demand SSBs—which suppress the transmission of Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) blocks (SSBs) and only transmit SSBs when necessary—is being investigated.

[0003] Existing technical documents Non-patent literature Non-patent document 1: 3GPP (registered trademark) document RP-234065. Summary of the Invention

[0004] The problem that the invention aims to solve Non-patent document 1 points out that a method for supporting on-demand SSB operation in secondary cells (Scells) should be studied in an environment where a terminal device in a connected state of carrier aggregation communication exists.

[0005] means for solving problems This invention provides a procedure for performing on-demand SSB operations for secondary cells in carrier aggregation.

[0006] One aspect of the present invention relates to a terminal device that conforms to the 3rd Generation Partnership Project (3GPP) cellular communication standard, wherein the terminal device comprises: a receiving unit that receives from a base station device providing carrier aggregation second setting information that differs from first setting information in the case where the transmission of synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) in a secondary cell is not suppressed, and where at least a portion of the SSB is not transmitted; a setting unit that performs a measurement setting for the SSB in the secondary cell based on the second setting information; and a measurement unit that uses the measurement setting to measure the SSB transmitted in the secondary cell.

[0007] One aspect of the present invention relates to a base station apparatus that conforms to the 3rd Generation Partnership Project (3GPP) cellular communication standard, wherein the base station apparatus comprises: a providing unit that provides a carrier-aggregated primary cell to a connected terminal device; and a transmitting unit that transmits to the terminal device second setting information that differs from first setting information in the case where the transmission of synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) in the carrier-aggregated secondary cell is not suppressed, and in the case where at least a portion of the SSB is not transmitted.

[0008] Invention Effects According to the present invention, on-demand SSB operations of secondary cells in carrier aggregation can be performed.

[0009] Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. It should be noted that, in the drawings, the same or identical structures are labeled with the same reference numerals. Attached Figure Description

[0010] The accompanying drawings are included in and form a part of the specification, illustrating embodiments of the invention and serving, together with the description, to explain the principles of the invention.

[0011] Figure 1 This is a diagram illustrating an example of the structure of a wireless communication system.

[0012] Figure 2A This is a diagram illustrating an example of the SSB's transmission mode.

[0013] Figure 2B This is a diagram illustrating an example of the SSB's transmission mode.

[0014] Figure 2C This is a diagram illustrating an example of the SSB's transmission mode.

[0015] Figure 2D This is a diagram illustrating an example of the SSB's transmission mode.

[0016] Figure 2E This is a diagram illustrating an example of the SSB's transmission mode.

[0017] Figure 3 This is a diagram illustrating an example of the processing flow performed in a wireless communication system.

[0018] Figure 4 This is a diagram illustrating an example of the processing flow performed in a wireless communication system.

[0019] Figure 5 This is a diagram used to explain the setup for SSB measurement.

[0020] Figure 6AThis is a diagram used to illustrate the relationship between Cell-DTX / DRX and SSB transmissions.

[0021] Figure 6B This is a diagram used to illustrate the relationship between Cell-DTX / DRX and SSB transmissions.

[0022] Figure 6C This is a diagram used to illustrate the relationship between Cell-DTX / DRX and SSB transmissions.

[0023] Figure 6D This is a diagram used to illustrate the relationship between Cell-DTX / DRX and SSB transmissions.

[0024] Figure 7 This is a diagram illustrating an example of the hardware configuration of a base station device and a terminal device.

[0025] Figure 8 This is a diagram illustrating an example of the functional configuration of a terminal device.

[0026] Figure 9 This is a diagram illustrating an example of the functional configuration of a base station device in a main cell. Detailed Implementation

[0027] The embodiments will now be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments are not intended to limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the invention. Any combination of two or more features described in the embodiments may be used. Additionally, identical or identical components are labeled with the same reference numerals, and repeated descriptions are omitted.

[0028] Figure 1 This illustrates an example configuration of the wireless communication system described in this embodiment. This wireless communication system is a cellular communication system conforming to 5G or subsequent cellular communication standards, based on the 3rd Generation Partnership Project (3GPP). In one example, the wireless communication system is configured to include base station devices 101 to 103 and a terminal device 111. It should be noted that... Figure 1 Only one terminal device and three base station devices are shown, but the representation is not limited to this; multiple terminal devices and multiple base station devices can certainly exist. Base station devices 101 to 103 each form one or more cells. Figure 1 In the example, base station device 101 forms cells 121 and 122, base station device 102 forms cell 123, and base station device 103 forms cell 124. It should be noted that in... Figure 1The diagram shows examples where base station devices 102 and 103 each form only one cell, but they can also form multiple cells. Additionally, in Figure 1 The diagram illustrates an example where base station device 101 forms cell 122, which is included within cell 121; however, these cells can also be formed to cover the same area. Additionally, for example, base station devices 101 to 103 can be connected to a common gNodeB-Central Unit (gNB-CU) and implemented as Transmit / Receive Points (TRPs) configured in geographically separated locations. Furthermore, each cell can correspond to a component carrier (frequency band). Additionally, each cell can correspond to a different frequency band or a common frequency band. It should be noted that in this embodiment, at least the frequency band corresponding to cell 121 is different from the frequency bands corresponding to cells 122 to 124; the frequency bands corresponding to cells 122 to 124 can be different from each other or the same.

[0029] In this embodiment, terminal device 111, for example, uses cell 121 formed by base station device 101 as the primary cell (Pcell) and is in an RRC connection state with base station device 101. In this state, terminal device 111 can use carrier aggregation (CA) to communicate via multiple cells (multiple component carriers). Base station device 101, which provides the primary cell to terminal device 111, can send a Radio Resource Control (RRC) message (e.g., an RRC reconfiguration message) to terminal device 111 in cell 121, which includes a setting that enables terminal device 111 to configure cells 122 to 124 as secondary cells (Scells). It should be noted that terminal device 111 can establish a connection with the secondary cell on the premise that a connection has been established with the primary cell (in an RRC connection state with the base station device of the primary cell).

[0030] There are two methods for adding secondary cells (Scells) in a CA. In the first method, the network (base station device 101) adds secondary cells based on a measurement report of the signal strength or signal quality of the terminal device 111. For example, a cell can be added as a secondary cell if the signal strength or signal quality (e.g., Reference Received Power (RSRP) or Reference Received Quality (RSRQ)) of a candidate cell (adjacent cells such as cells 122 to 124 relative to the primary cell 121) exceeds a predetermined threshold (e.g., in the case of Event A4 as specified in the standard). Conversely, a cell can be removed from the secondary cells if the signal strength or signal quality of a cell set as a secondary cell falls below a predetermined threshold (e.g., in the case of Event A2 as specified in the standard). Here, the terminal device 111 can measure the signal strength or signal quality, for example, by observing the Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) blocks (SSBs) transmitted in each cell. It should be noted that, in addition to measuring signal strength or signal quality, the SSB is also used to allow the terminal device 111 to obtain downlink time and frequency synchronization and basic system information between itself and the cell that sent the SSB. The method of adding a secondary cell based on signal strength and signal quality measurement results may result in a relatively large delay before the addition of the secondary cell is completed, because the processing of sending measurement reports from the terminal device to the base station device takes a certain amount of time. On the other hand, this method can be applied to various scenarios, such as situations where the base station device providing the primary cell (Pcell) and the base station device providing the secondary cell cannot be considered to exist in the same location. In the second method, the network does not use the signal strength or signal quality measurement results of the terminal device to add the secondary cell. This method of adding a secondary cell without using measurement results can shorten the delay until the addition of the secondary cell is completed because the time required for setting the processing is relatively short. This method can only be applied when the base station device providing the primary cell and the base station device providing the secondary cell can be considered to exist in the same location. It should be noted that the addition or deletion of a secondary cell can be performed, for example, via Radio Resource Control (RRC) messages.

[0031] In addition to adding or deleting secondary cells, the added secondary cells can be activated or deactivated. That is, the added secondary cell can be activated when in actual use and deactivated when not in use. The base station device 101 providing the primary cell can determine whether to activate or deactivate a secondary cell (e.g., at least one of cells 122 to 124) based on factors such as increases or decreases in the throughput demand of the terminal device 111 or changes in cell quality. Alternatively, the base station device 101 can also determine whether to activate or deactivate a secondary cell without relying on a measurement report when adding the secondary cell. It should be noted that activation or deactivation can be indicated, for example, by the secondary cell state information element included in the RRC message. This secondary cell state information element can indicate whether the added secondary cell is activated (whether it is in an activated state). Furthermore, based on the measurement report from the terminal device 111, the Media Access Control-Control Element (MAC CE) can specify whether the secondary cell should be activated or deactivated. This MAC CE can be referred to as an Activation / Deactivation MAC CE. Terminal device 111 receives a MAC CE for activating the secondary cell and starts a timer (scelldeactivationtimer) after the secondary cell is activated. Then, terminal device 111 activates the secondary cell when the timer expires or when it receives a Deactivation MAC CE.

[0032] Therefore, in order to add, delete, activate, and deactivate secondary cells, it is important to be able to measure the signal strength or signal quality of the secondary cell (or a candidate cell for addition) in the terminal device 111. To perform such measurements, the terminal device 111 can receive information such as the transmission period, number of beams, and beam direction (parameters representing azimuth and phase) of SSBs in surrounding cells from an RRC message (e.g., an RRC reconfiguration message) sent from the base station device 101 of the connected primary cell. The terminal device 111 can obtain this information from the bitmap of the SSBs specified by the ssb-positionsInBurst for secondary cells within the RRC message. Furthermore, the terminal device 111 determines the timing, measurement period, and measurement cycle for measuring the SSBs of the added secondary cell from the secondary cell config within the RRC message (e.g., an RRC reconfiguration message) received in the primary cell. Terminal device 111 verifies the SSB-based RRM Measurement Timing Configuration (SMTC) included in scellconfig, which determines the start time, measurement period, and measurement cycle for each cell. The period during which this measurement is performed can be called the SMTC window. Terminal device 111 performs SSB detection and measurement of the secondary cell within the SMTC window and reports the results to base station device 101. Alternatively, the measurement period (SMTC) information can also be included in the measobjectNR, which is an information element within the RRC message. That is, terminal device 111 can verify the measobjectNR to determine the measurement period, perform SSB measurement of the secondary cell within that period, and report the measurement results to base station device 101.

[0033] Currently, there is a demand for power saving in networks, and research is being conducted on suppressing the transmission of SSBs in secondary cells. In this embodiment, such a secondary cell with suppressed SSB transmission is called an SSB-less secondary cell. An SSB-less secondary cell is a cell that is designated as a secondary cell for terminal device 111, and whose SSB transmission is stopped for power saving, has a longer transmission period than in non-power-saving operation, or does not transmit a portion of SSBs. In one example, a cell that is not activated and does not provide data communication services among the secondary cells designated for terminal device 111 can be an SSB-less secondary cell. In addition, depending on the situation, even activated cells can operate as SSB-less secondary cells. For example, in a portion of the beam formed by secondary cells that provide communication services to the terminal device, the transmission of SSBs can be stopped, the transmission period can be extended, etc.

[0034] Here, use Figures 2A-2E An example of reducing transmission power consumption by suppressing SSB transmission in a secondary cell without an SSB is given. It should be noted that... Figure 2A This illustrates a previous scenario without SSB transmission suppression. Figures 2B-2E An example of SSB transmission suppression is shown. Additionally, although not in... Figures 2A-2E As shown, it is also possible to make a cell without an SSB completely refrain from transmitting SSBs during a predetermined period. Figures 2A-2E In the diagram, rectangles represent resources for frequency and time, while shaded areas represent resources for transmitting SSBs. Figure 2A The example illustrates the resource prepared for SSB transmission every 20 milliseconds (ms), and the state of transmitting SSBs in the respective directions of multiple beams formed within the cell in a time-division manner within that resource. In a secondary cell without SSBs, for example... Figure 2B As shown, by extending the transmission period of the SSB, the number of times the SSB can be transmitted can be reduced, thus saving power. Figure 2B The example illustrates a 160ms transmission period for the SSB. In this way, the transmission probability of the SSB becomes 1 / 8, thus suppressing power consumption in a cell without an SSB. It should be noted that the period is not limited to this; the SSB can be transmitted with a period shorter or longer than 160ms. However, this period is set to be longer than the case without power-saving actions. Furthermore, in a cell without an SSB, such as... Figure 2C As in the example, a wider beam is prepared to uniformly cover an area covered by multiple beams, and SSBs are transmitted through this beam, thereby reducing the chances of SSBs being transmitted. Figure 2A In this state, SSBs are transmitted in each of the eight beams; conversely, in... Figure 2C In the example, SSBs are transmitted in two beams with wider beamwidths. According to this method, the transmission probability of SSBs becomes 1 / 4, thus suppressing the power consumption associated with SSB transmission in secondary cells without SSBs, thereby reducing network power consumption. Furthermore, if, for example, more than one beam corresponding to the location of a terminal device providing communication services can be determined in advance, SSBs can be transmitted only to that one or more beams. Figure 2D The example illustrates the case where the number of beams transmitting SSBs is reduced from eight to four. In this way, the transmission opportunity for SSBs is halved, thus suppressing the power consumption associated with SSB transmissions in SSB-less secondary cells, thereby reducing network power consumption. Additionally, as... Figure 2E In this way, although SSBs are transmitted to all beams, within a single SSB transmission opportunity, SSBs can be transmitted only to a subset of beams. Figure 2EThe example illustrates how, in a single SSB transmission opportunity (arriving at 20ms intervals), only four beams are used to transmit the SSB. In this case, the number of SSBs transmitted in a single transmission opportunity is halved, thus suppressing the power consumption associated with SSB transmission in SSB-free secondary cells and consequently reducing network power consumption.

[0035] As mentioned above, in a secondary cell without an SSB, SSBs can be transmitted in various modes. The following will... Figures 2A-2E The mode used for transmitting SSBs in the configuration is called the setting mode. If the terminal device performs measurements based on conventional measurement information, it may become inefficient due to situations such as failing to transmit an SSB at the specified measurement time, depending on the SSB setting mode. Furthermore, the terminal device cannot recognize the existence of an untransmitted secondary cell's SSB, and therefore cannot perform the processing for using that SSB. Thus, in the presence of a secondary cell without an SSB, performing conventional terminal device operations may lead to reduced system efficiency or system instability. Therefore, in this embodiment, a procedure for efficiently utilizing secondary cells without SSBs is provided.

[0036] <Notification of Setting Mode Information> The base station device of the primary cell generates SSB configuration mode information for each of the multiple configuration modes mentioned above, for a secondary cell without an SSB, and notifies the terminal device of this information. The configuration mode information includes, for example, information related to the SSB configuration mode, such as (e.g., represented by the variable ARFCN-ValueNR), the frequency of SSB transmission, (e.g., represented by the variable ssb-periodicityServingCell), the number of beams, and the beam direction (e.g., information indicating at least one of the directions of beams transmitting SSBs and beams not transmitting SSBs). Additionally, the configuration mode information may also use the measurement period and timing (SSB-MTC) for SSB measurement to represent a portion of the configuration mode characteristics. That is, the measurement period and timing information for SSB measurement can be notified to the terminal device as part of the configuration mode information.

[0037] Furthermore, the base station apparatus of the primary cell may, for example, include in its configuration mode information information whether reference signals such as Tracking Reference Signal (TRS) or Channel State Information-Reference Signal (CSI-RS) transmitted in this apparatus have attributes common to SSBs that are suppressed (stopped from transmission) in secondary cells without SSBs. Whether the attributes are common can be communicated to the terminal device, for example, using specifications related to QCL (Quasi Co-Location) (using information such as qcl-Type). For example, the base station apparatus of the primary cell may also form secondary cells at the same location based on the primary cell. Here, in these cells, if beams are formed in the same direction, it is conceivable that the Doppler offset, Doppler spread, average delay, and delay spread are common to the beams corresponding to the same direction in these cells, for example, if the frame transmission timing is consistent. Therefore, when the secondary cell is an SSB-less secondary cell and SSB transmission is stopped in a portion of its beams, the base station device of the primary cell can include information indicating the relationship with the corresponding beam (reference signal) of the primary cell (QCL type qcl-TypeA) in the setting mode information and send it to the terminal device for the stopped beam (SSB). If the reference signal of the primary cell and the SSB of the SSB-less secondary cell have common attributes, the measurement results of the reference signal of the primary cell can be transferred to the SSB-less secondary cell. For example, the terminal device can transfer the time and frequency synchronization obtained from the TRS measurement results of the primary cell to the SSB-less secondary cell. In this case, the terminal device does not need to request the transmission of SSBs for the SSB-less secondary cell. It should be noted that the relationship between the SSB (beam) of the SSB-less secondary cell and the SSB (beam) of other secondary cells can also be specified. In this embodiment, the SSB transmitted according to request is called on-demand SSB. When a terminal device needs to receive SSBs for Layer 1 or Layer 3 measurements or other processing, it can request on-demand SSB transmission from a secondary cell without an SSB, without relying on the QCL. It should be noted that this information can be communicated to the terminal device, for example, through an information element such as scellactivationRS-config, which is used to set a reference signal for high-speed activation of the secondary cell. However, this is just one example; this information can also be communicated in other existing information elements, or new information elements can be defined.

[0038] Additionally, in the configuration mode information, when the terminal device can use the synchronization signals of other cells to establish synchronization in a cell without an SSB, information may be included for the terminal device to determine the SSB index of the SSB that is suppressed in the cell without an SSB based on synchronization with other cells. This information may be sent as, for example, deriveSSB-Indexfromcell or deriveSSB-IndexFromCellInter. Here, deriveSSB-Indexfromcell is used to derive the SSB index of other cells in multiple cells based on the Super Frame Number (SFN) and the frame boundary alignment in the time region, and based on the SFN and frame position of the cell (serving cell) that is currently providing communication services to the terminal device. It should be noted that deriveSSB-indexfromcell can be used regardless of whether the associated cells are provided by a base station device configured in the same location (which can be considered as the same location). For example, the terminal device can determine the SSB index of the first secondary cell based on synchronization with a second secondary cell (information related to the time and frequency region of the second secondary cell) that is determined not to perform power-saving operations based on received information. For instance, the first secondary cell transmits SSBs with SSB indices 1 to 4 without performing power-saving operations, but stops transmitting SSBs with SSB indices 2 and 3 when performing power-saving operations. In this case, the terminal device can, for example, determine the SSB indices 2 and 3 of the SSBs that are stopped in the first secondary cell based on the SSBs transmitted in the second secondary cell, and request on-demand SSB transmission from the network side as needed.

[0039] It should be noted that, for example, if the terminal device determines that the SSB index of the SSB that has stopped transmitting in the first secondary cell is 2 and 3, it may request that all of these SSBs be transmitted as on-demand SSBs, or it may request only a portion of them to be transmitted.

[0040] For example, a base station device in a first secondary cell performing power-saving operation and a base station device in a second secondary cell not performing power-saving operation are arranged to exist in (approximately) the same location. Furthermore, when the base station device in the first secondary cell is not performing power-saving operation, the beam directions corresponding to SSBs with SSB indices 1-4 are (approximately) aligned with the beam directions of SSBs with SSB indices 1-4 in the second secondary cell. Here, it is assumed that the terminal device is receiving communication services via the second secondary cell. Additionally, when the base station device in the first secondary cell is performing power-saving operation, the transmission of SSBs with SSB indices 1-4, specifically SSBs with SSB indices 2 and 3, is suppressed (stopped). Here, the case where the terminal device determines that the signal strength or signal quality in the second secondary cell is lower than that in the first secondary cell is investigated. In this case, the terminal device compares the signal strength or signal quality of SSBs with SSB indices 2 and 3 in the second secondary cell. Moreover, it is assumed that the terminal device determines that the signal strength or signal quality of the SSB with SSB index 2 is better than that of the SSB with SSB index 3. In this scenario, the terminal device can also assume that the signal strength or quality of the SSB with an SSB index of 2 is better than that of the SSB with an SSB index of 3 in the first secondary cell. Furthermore, the terminal device can request the network to transmit the SSB with an SSB index of 2, but not the SSB with an SSB index of 3. Thus, even when the transmission of a portion of the SSBs in the first secondary cell is stopped, and the beam of the first secondary cell corresponds to the beam of the second secondary cell (adjacent cell), the terminal device does not need to request the transmission of on-demand SSBs for all the SSBs that are stopped in the first secondary cell, but can request the transmission of on-demand SSBs only for a portion of the SSBs. This prevents increased power consumption in SSB-less secondary cells.

[0041] Furthermore, even if the base station device of the first secondary cell performing power-saving operation and the base station device of the second secondary cell not performing power-saving operation but providing communication services to the terminal device are located in different positions, the terminal device can still request the transmission of only a portion of the SSBs that are stopped (suppressed) in the first secondary cell, in a state where power-saving operation is not performed. For example, the terminal device detects a beam fault in the beam corresponding to SSB index 1 in the first secondary cell, and further fails to recover from the beam fault in the beam corresponding to SSB index 4, which is preset for recovery from the beam fault. In this case, the terminal device can request the transmission of SSBs with SSB indices 2 to 3 for the determination of other beams in the first secondary cell. Here, the terminal device, for example, refers to the derivedssb-Indexfromcell and determines the SSB indices of the first secondary cell as 2 and 3 based on the information of the second secondary cell. For example, if the direction of the beam corresponding to each SSB index in the first secondary cell is identified by preset settings, the terminal device can deduce which beam it is located at. Furthermore, in one example, if the terminal device determines that it is located in the direction of the beam corresponding to SSB index 2, it can request the transmission of on-demand SSBs from the network for the SSB with SSB index 2. In this way, the terminal device does not need to request the transmission of all on-demand SSBs that are suppressed for transmission, but can request the transmission of on-demand SSBs only for a portion of the SSBs. This prevents increased power consumption in SSB-less secondary cells.

[0042] It should be noted that, for example as described above, there are multiple power-saving operation settings in each secondary cell, and the secondary cell can selectively use these multiple settings as needed. That is, it is conceivable that multiple setting mode information is needed for one secondary cell. In this case, identification information can be assigned to each of these multiple setting mode information. Alternatively, setting mode information for the case where SSB transmission is suppressed and setting mode information for the case where SSB transmission is not suppressed can be prepared separately, and identification information for identifying them can be assigned. It should be noted that when there is only one setting mode information for the case where SSB transmission suppression is performed, the identification information can be information indicating whether SSB transmission suppression is performed. Furthermore, regarding this identification information, if information elements are defined separately for the case where SSB transmission suppression is performed and the case where SSB transmission suppression is not performed, since the determination of whether SSB transmission suppression is performed is based on the name of the information element, identification information may not be prepared at least for the case where SSB transmission suppression is not performed. The base station device of the primary cell can simultaneously or separately notify the terminal device of the setting mode information for each secondary cell and the identification information indicating the setting mode used in the secondary cell. The terminal device can determine one (or more) setting mode information based on identification information associated with the setting mode information, from setting mode information when no power-saving action is performed and more than one setting mode information used for power-saving action. It should be noted that when multiple setting mode information is determined, SSB transmissions between both parties using those multiple setting mode information can be performed in the secondary cell.

[0043] It should be noted that, for example, only the setting mode information currently used in the secondary cell may be notified to the terminal device. For instance, when no power-saving operation is performed in the secondary cell, the setting mode information of the SSB used to perform that power-saving operation may be notified to the terminal device. Conversely, when a power-saving operation is performed in the secondary cell, only the setting mode information used in that power-saving operation may be notified to the terminal device. In this case, identification information for recognizing the setting mode information may not be required.

[0044] The base station device of the primary cell can notify the terminal device of all the aforementioned configuration mode information through a single RRC message (e.g., an RRC reconfiguration message). It should be noted that the base station device of the primary cell can also use multiple RRC messages or messages from other layers to disperse the notification of the aforementioned configuration mode information to the terminal device. The base station device of the primary cell can then use MAC CE and Downlink Control Information (DCI) to notify the terminal device of the identification information used in the secondary cell to determine the configuration mode information. It should be noted that, as mentioned above, when only the configuration mode information used in the secondary cell is notified, and unused configuration mode information is not notified, only the aforementioned RRC message can be sent, without sending the subsequent MAC CE and DCI. It should be noted that MAC CE and DCI can be used to dynamically or semi-persistently notify the identification information specifying the configuration mode information in use. In one example, when dynamically notifying the use of the configuration mode information, the notification can include information indicating the validity period of the configuration mode information. Furthermore, the transmission of the SSB using the configuration mode information is performed within the indicated period. During the specified period, the terminal device performs an SSB measurement based on the specified configuration mode information and, for example, sends the measurement result to the base station device of the primary cell. It should be noted that after the period ends, the base station device of the primary cell can, via another DCI, instruct the terminal device to specify identification information for the configuration mode information of the SSB currently in use, as well as information indicating its validity period. In the case of semi-permanently notifying the user of the used configuration mode information, the notification may, for example, include information indicating the activation or deactivation of a specific configuration mode information. The activated configuration mode information can be used until notified of deactivation or activation of another configuration mode information.

[0045] Here, use Figure 3Here is an overview of an example of the process described above. It should be noted that this process can be modified in various ways as described above or later, but only the general process flow is described here, without mentioning such modifications. In this process, the base station device of the primary cell sends, for example, setting information from the secondary cell that provides component carriers for carrier aggregation to the terminal device, including SSB setting mode information, to the terminal device (S301). Here, the SSB setting mode information may include setting mode information without SSB transmission suppression and setting mode information with SSB transmission suppression, and identification information is assigned to each. It should be noted that, as mentioned above, identification information is not necessarily required. The terminal device retains the received setting mode information (S302). It should be noted that when the terminal device receives setting information associated with the setting mode information and identification information, it stores the identification information associated with the setting mode information. Subsequently, in order to enable the terminal device to measure the SSB sent from the base station device of the secondary cell, the base station device of the primary cell sends a message to the terminal device containing identification information indicating which of the setting mode information sent in S301 should be used for measurement (S303). The terminal device, for example, determines the setting mode information to be used based on the identification information contained in the indication and performs the setting for measurement (S304). It should be noted that in S303, information indicating whether SSB transmission suppression is performed may also be provided. Based on this information, the terminal device can select either the setting mode information for SSB transmission suppression or the setting mode information for not SSB transmission suppression, and perform the measurement setting using the selected setting mode information. Afterwards, the terminal device can measure the SSB sent from the base station device of the secondary cell (S305) and send a report of the measurement result to the base station device of the primary cell (S306). It should be noted that when the base station device of the primary cell only sends the setting mode information currently in use in the secondary cell, the notifications of S301 and S303 can be performed at once, and the processing of S302 and S304 in the terminal device can also be performed at once.

[0046] It should be noted that a cell without an SSB can be associated with a combination of multiple configuration mode information. That is, for a cell without an SSB, for example, it can be associated with a combination of multiple configuration mode information. Figures 2B-2EOne or more related setting mode information defines a set of setting information, and multiple setting information consisting of such a combination of setting modes can be prepared. Furthermore, the base station device of the primary cell can, for example, use RRC messages to combine the setting information consisting of one or more setting mode information (combinations) with identification information ("#1" to "#3") for the SSB-free secondary cell, such as {#1: setting information 1; #2: setting information 2; #3: setting information 3}, and notify the terminal device. After notifying the terminal device of this information, the base station device of the primary cell can notify the terminal device via MAC CE or DCI, such as {Activated: #2}, to activate which setting information is being activated. For example, when notifying the terminal device with information such as {Activated: #2}, one or more setting modes corresponding to the identification information "#2" can be activated. It should be noted that when multiple SSB-free secondary cells are set for the terminal device, the above-mentioned information about the multiple SSB-free secondary cells can be notified to the terminal device via one or more RRC messages. For example, the base station device of the primary cell uses RRC messages to notify the terminal device of information such as {Secondary Cell 1: #1: Setting Information 1; Secondary Cell 1: #2: Setting Information 2; Secondary Cell 1: #3: Setting Information 3; Secondary Cell 2: #1: Setting Information 1; Secondary Cell 2: #2: Setting Information 2; Secondary Cell 2: #3: Setting Information 3; Secondary Cell 3: #1: Setting Information 1; Secondary Cell 3: #2: Setting Information 2; Secondary Cell 3: #3: Setting Information 3; Secondary Cell 3: #4: Setting Information 4}. Afterwards, the base station device of the primary cell can notify the terminal device of information such as {Activated: Secondary Cell 1: #2; Secondary Cell 3: #3} via one or more MAC CEs or DCIs. This information indicates that the setting information 2 of the first secondary cell (secondary cell 1) and the setting information 3 of the third secondary cell (secondary cell 3) have been activated.

[0047] Additionally, in secondary cells without SSBs, the configuration mode information for transmitting on-demand SSBs can be defined. In this case, when transmitting on-demand SSBs, the terminal device can be notified of the identification information corresponding to the configuration mode information. The terminal device then performs measurement settings based on the configuration mode information and receives the on-demand SSB. It should be noted that this is just one example; for instance, when transmitting on-demand SSBs, the terminal device can also be notified of the configuration mode information for using a mode without SSB transmission suppression. In this case, the terminal device is in a state where it can measure all SSBs, and therefore can also perform on-demand SSB measurement.

[0048] <On-Demand SSB Sending Request> Under predetermined conditions, the terminal device can send a message to the network (the base station device of the primary or secondary cell providing the connection) requesting on-demand SSB transmission for SSBs that are suppressed (stopped) in a secondary cell without an SSB. For example, the terminal device can send the above request to the network when a predetermined event occurs, such as the signal strength or signal quality of the beam of the secondary cell used for communication becomes lower than that of the beam transmitting an SSB in the secondary cell without an SSB. As such an event, conventional events such as Event A2 (an event that occurs when the signal strength or signal quality of the secondary cell (serving cell) in use is lower than a predetermined threshold) and Event A6 (an event that occurs when the signal strength or signal quality of a neighboring cell (here, a secondary cell without an SSB) exceeds a value equal to the signal strength or signal quality of the secondary cell in use plus a predetermined offset) can be used. Furthermore, if, for example, the terminal device experiences a change in signal strength or signal quality per unit time exceeding a predetermined threshold, or if the duration of such a change exceeding the predetermined threshold exceeds a predetermined duration, it may request on-demand SSB transmission from a SSB-free secondary cell. For instance, when the terminal device is in a high-speed moving state, it is assumed that the change in signal strength or signal quality per unit time increases. In such a state, it is assumed that the terminal device frequently changes the beam of the connection target, and in order to quickly measure this, it may request on-demand SSB transmission from an SSB-free secondary cell. It should be noted that the terminal device may also determine its own movement state through sensors or the like, without relying on the measurement results of signal strength or signal quality changes, and request on-demand SSB transmission from an SSB-free secondary cell when the device is in a high-speed moving state. Additionally, if, for example, the terminal device detects a beam fault in the beam used for communication, it may request on-demand SSB transmission to confirm whether a suitable beam exists besides the beam pre-set for beam fault recovery. In addition, when the terminal device uses the aforementioned derivessb-Indexfromcell and deriveSSB-IndexFromCellInter to determine the SSB index of a cell without an SSB based on the reference signal of a specific cell, in addition to the above conditions, it can also request the transmission of on-demand SSBs for the SSBs that are suppressed (stopped) in the cell without an SSB when the signal strength or signal quality of the cell transmitting the reference signal is lower than the signal strength or signal quality of the SSB being transmitted in the cell without an SSB.

[0049] These conditions for requesting on-demand SSB transmission can be notified to the terminal device in advance, for example, by the base station device of the primary cell. It should be noted that some of these conditions may also be held by the terminal device in advance. Furthermore, based on the above conditions, the base station device can also indicate the timing at which an on-demand SSB transmission request from the terminal device can begin. That is, the on-demand SSB transmission request can be made possible only during a specific period. The terminal device can request on-demand SSB transmission if at least one of the above conditions is met during this period. It should be noted that the terminal device will not request on-demand SSB transmission even if the above conditions are met outside of this period. Outside of the notified period, the terminal device may not even perform a determination of whether the conditions are met. Furthermore, the base station device may ignore the on-demand SSB transmission request even if it receives it outside of this period. It should be noted that the base station device can notify the terminal device of the above conditions (e.g., using RRC messages) along with the SSB configuration mode information. Alternatively, the base station device can use MAC CE and DCI to notify the terminal device of the period during which an SSB transmission request can be made (e.g., start time and end time). Furthermore, the base station device can prepare a Radio Network Temporary Identifier (RNTI) for each group of terminal devices containing one or more terminal devices, and use the RNTI to notify the terminal device of the aforementioned conditions and the period during which an SSB transmission request can be made on a group basis. Alternatively, the base station device can notify the terminal device of the aforementioned conditions and the period during which an SSB transmission request can be made on a cell basis. That is, terminal devices belonging to the same cell can be grouped together and the information can be notified as a group. This notification can be performed, for example, via DCI.

[0050] For example, a terminal device may send a transmission request to the base station device of the primary cell (or the secondary cell used for communication) containing the identifier (Scellindex) of the secondary cell without an SSB that should transmit on-demand SSBs. This transmission request may include, for example, at least one of the following: information requesting a change in the transmission period of the SSB, information specifying the SSB to be transmitted, and information specifying the direction of the beam from which the SSB should be transmitted. Additionally, the transmission request may also include information indicating the intended use of the on-demand SSB (e.g., for Radio Resource Management (RRM) determination, for time / frequency synchronization, etc.). It should be noted that the transmission of a specific SSB can also be requested using the SSB index, an index representing the SSB's configuration mode information.

[0051] It should be noted that the terminal device can use Layer 3 (RRC layer) messages to send an on-demand SSB transmission request to the base station of the primary cell. For example, UE Assistance information, periodic or event-driven Measurement reports can be used for the on-demand SSB transmission request. Alternatively, the terminal device can also use Layer 2 (MAC layer) messages to send this request. In the event of a beam failure detected in a secondary cell, the BFR MAC CE sent to the base station of the primary cell for beam failure recovery can include the request for an on-demand SSB. Furthermore, the terminal device can also use other MAC CEs such as Enhanced BFR MAC CE, Buffer Status Report MAC CE, Power Head Room (PHR) MAC CE, and Configured Grant Confirmation MAC CE to request the transmission of an on-demand SSB. Finally, the terminal device can also use Layer 1 (PHY layer) messages to send this request. For example, a terminal device can request on-demand SSB transmission from a secondary cell using a scheduling request (SR) to the base station of the primary cell, or resources allocated by a configured grant (at least one of type 1 / type 2). In this case, a scheduling request identifier and resources different from those used in previous scheduling requests can be used. Alternatively, uplink resources can be prepared via a dedicated configured grant to request on-demand SSBs.

[0052] Furthermore, when Cell DTX / DRX as specified in the Rel-18 standard is configured in the primary cell, the primary cell's base station cannot receive the uplink data and control information inherent to the terminal device during the Cell DRX inactive period. That is, the terminal device cannot send the aforementioned messages during the Cell DRX inactive period (and even if it does, the primary cell's base station cannot receive them). On the other hand, Cell DRX does not apply to SSB, paging, System Information Block (SIB), and Random Access Channel (RACH), which stipulate that these signals are transmitted and received even during inactive periods. Therefore, in one example, the terminal device can use the Physical Random Access Channel (PRACH) of the primary cell's base station to request the on-demand transmission of SSBs from the secondary cell. For example, the terminal device sends a PRACH to the primary cell's base station, causing the primary cell to transition to an active state. It should be noted that the active state here refers to a state capable of transmitting and receiving signals; for example, it could be a state where Cell DTX / DRX is not used, or a state where signal transmission and reception occur during the Cell DTX / DRX inactive period. Subsequently, the terminal device can send a secondary cell on-demand SSB transmission request to the base station of the primary cell as described above. Alternatively, the terminal device can use the PRACH resource associated with a pre-defined secondary cell on-demand SSB transmission request to send a PRACH to the primary cell. In this case, the base station of the primary cell, upon receiving the PRACH sent from this resource, can recognize that an on-demand SSB transmission request has been received. With such PRACH resources configured, although other communication is not possible within these resources, it is possible to operate without requiring the primary cell with Cell DTX / DRX configured to be in an active state.

[0053] When the base station of the primary cell receives an on-demand SSB transmission request, it forwards the request, for example via the Xn interface, to the base station of the secondary cell without an SSB. Furthermore, the base station of the secondary cell without an SSB can perform on-demand SSB transmission based on this transmission request.

[0054] The above example illustrates a terminal device requesting on-demand SSB transmission, but is not limited to this. For instance, when a primary cell instructs a terminal device to activate a secondary cell that is an SSB-free secondary cell, it may require information about the signal strength or signal quality of that secondary cell in the terminal device, or time / frequency synchronization between the terminal device and that secondary cell. In such a case, the primary cell's base station can request on-demand SSB transmission from the base station of the SSB-free secondary cell even if it has not received a request from the terminal device. Before sending a MAC CE (Activation and Deactivation Message Code) to a terminal device to activate or deactivate a secondary cell that is a secondary cell without an SSB (Segmented Subsidiary Cell), the base station device of the primary cell may, via the MAC CE and DCI (Distribution and Control Code), notify the terminal device of the identification information of (one or more) secondary cells without an SSB that are sending on-demand SSBs, the start time of the on-demand SSB transmission from that secondary cell (e.g., the offset from the time of the MAC CE and DCI transmission), the end time of the on-demand SSB transmission (the time when on-demand SSBs will no longer be sent), and the setting mode information of the on-demand SSB (e.g., the SSB index of the transmitted SSB). In addition to the above-mentioned start and end times of on-demand SSB transmission, as an example, it may also be possible to notify the terminal device of the periodic transmission of on-demand SSBs from the secondary cell without an SSB starting from a set transmission time. It should be noted that even without such notification, the terminal device can be considered to be sending on-demand SSBs at a predetermined period between the start and end times of transmission. That is, it is envisioned that when the terminal device receives information indicating a specified start time for transmission, it periodically transmits on-demand SSBs from that start time and is capable of measuring the on-demand SSBs. It should be noted that, in this case, without prior notification of the end time for transmission, the terminal device can be considered to periodically transmit the on-demand SSBs until it receives a notification from the base station device of the main cell to stop transmitting the on-demand SSBs.

[0055] It should be noted that the base station device of the primary cell can notify the terminal device in advance of this information as one of the configuration mode information described in the aforementioned <Configuration Mode Information Notification>, and then specify this configuration mode information through MAC CE and DCI when actually performing on-demand SSB transmission. Alternatively, the base station device of the primary cell can also notify the terminal device separately of the resources for transmitting on-demand SSBs, their transmission period, and transmission start time, as information different from the aforementioned configuration mode information. After receiving the above information, the terminal device starts on-demand SSB measurement based on the specified information and reports the measurement results to the base station device of the primary cell. Furthermore, after receiving the measurement results from the terminal device, the base station device of the primary cell determines whether on-demand SSB transmission is no longer necessary in the SSB-free secondary cell. Moreover, if the base station device of the primary cell determines that on-demand SSB transmission is no longer necessary, it requests the SSB-free secondary cell to stop on-demand SSB transmission and then notifies the terminal device that on-demand SSB transmission in the SSB-free secondary cell has been stopped.

[0056] In another example, the base station of the primary cell can, for instance, notify the terminal device of the number of times the on-demand SSB transmission has been completed, instead of the termination time of the on-demand SSB transmission in the SSB-free secondary cell. This transmission count is the number of times the on-demand SSB has been transmitted in the SSB-free secondary cell. After transmitting this number of on-demand SSBs (e.g., at a predetermined period notified to the terminal device), the transmission of the on-demand SSBs is stopped. It should be noted that the base station of the primary cell can notify the terminal device that the transmission of the on-demand SSBs in the SSB-free secondary cell has been stopped when the number of on-demand SSB transmissions in the SSB-free secondary cell reaches this number. Furthermore, upon receiving information including the aforementioned transmission count, the terminal can begin measuring the on-demand SSBs from the start time of transmission, count the number of measurements, and stop measuring the on-demand SSBs when the number of measurements reaches the notified transmission count (without receiving notification from the base station of the primary cell).

[0057] Alternatively, it can be used as Figure 2A Setting mode and Figure 2B The setting mode is switched in this way, changing the SSB transmission cycle according to the on-demand SSB request. That is, for example, in a secondary cell without an SSB, such as... Figure 2B When suppressing SSB transmission by extending the SSB transmission period, for example, based on on-demand SSB transmission requests, it can also be done only within a certain period of time. Figure 2AThis shortens the transmission cycle. In this case, the base station of the primary cell can notify the terminal device that the SSB in the secondary cell without an SSB will be transmitted in a first cycle during a predetermined period, and then transmitted in a second cycle (shorter than the first cycle) after the period ends. The base station of the primary cell, as information specifying the period for transmitting SSBs in the first cycle, can notify the terminal device of the transmission start time and transmission end time, and can also notify the terminal device of other information such as the transmission start time and the number of on-demand SSB transmissions. It should be noted that the base station of the primary cell can notify the terminal device of information regarding the SSB transmission cycle that changes according to the on-demand SSB request. It should also be noted that if the SSB transmission cycle according to the on-demand SSB request is the same as, for example, the transmission cycle of SSBs in other beams where SSB transmission is not suppressed, the terminal device may not be notified of this transmission cycle information. Furthermore, the base station of the primary cell can, for example, notify the terminal device of information related to the resources used for transmitting the SSB during the period of transmitting SSBs in the first cycle. Upon receiving this information, the terminal device performs SSB measurement within a specified period from the start of transmission, at a period corresponding to the SSB transmission cycle within that period. The SSB measurement cycle is then changed as the period ends. Furthermore, the base station device of the primary cell may send a predetermined notification to the terminal device at the start of transmission of a short-cycle SSB based on an on-demand SSB request. Additionally, it may send other predetermined notifications to the terminal device at the start of transmission of a long-cycle SSB following the end of transmission of that short-cycle SSB. That is, the terminal device may not be able to determine the aforementioned period in advance.

[0058] The base station device of the primary cell described above can send multiple settings related to the on-demand transmission of SSBs for each of the multiple SSB-less secondary cells to the terminal device via a single message, or via multiple messages. In one example, two of the three settings related to three SSB-less secondary cells can be sent via a single message, and the remaining setting can be sent via a separate message.

[0059] All or part of the aforementioned information related to the transmission of on-demand SSBs, or cell identifiers related to SSB-less secondary cells, may be notified to the terminal device using at least one of RRC messages, MAC CE, and DCI. It should be noted that the aforementioned information may also be included in, for example, a MAC CE instructing the activation or deactivation of a SSB-less secondary cell. Additionally, the primary cell may, along with this notification, instruct the terminal device to report (event-trigger) reports, periodic, non-periodic, or semi-permanent reports caused by the event of transmitting on-demand SSB measurement results. It should be noted that this information may also be notified by the cell to which the terminal device belongs, or by a pre-defined group of terminal devices.

[0060] The terminal device receives an instruction from the base station of the primary cell and, based on the instruction or starting from a specified transmission start time, performs on-demand SSB measurement of the secondary cell according to a specified setting mode, and reports the measurement results to the primary cell. When the base station of the primary cell receives the report of the on-demand SSB measurement results from the terminal device, it determines, for example, whether to activate the secondary cell. Furthermore, if the base station of the primary cell determines that the secondary cell should not be activated, it can notify the secondary cell that SSB transmission should be suppressed or that SSB transmission can be suppressed. Additionally, when the base station of the primary cell suppresses SSB transmission in the secondary cell, it can notify the terminal device of information related to the transmission suppression of the secondary cell (e.g., the specification of setting mode information).

[0061] It should be noted that, in one example, the terminal device sends an on-demand SSB transmission request for the secondary cell to the base station of the primary cell. Upon receiving this transmission request, the base station of the primary cell sends a response message to the terminal device. It should also be noted that, for this response message, a previous message used for activating or deactivating the secondary cell can be used, or the message can be extended. For example, if the terminal device receives a message from the base station of the primary cell requesting activation of a secondary cell without an SSB, it can determine that the on-demand SSB transmission request was successful. Alternatively, the terminal device can also determine that the on-demand SSB transmission request was successful if, within a predetermined period after requesting the on-demand SSB transmission, it receives a message from the base station of the primary cell requesting deactivation of a currently activated secondary cell. Furthermore, the message extending the message for activating / deactivating the secondary cell can include information indicating acceptance of the on-demand SSB transmission request. Additionally, other RRC messages, MAC CE, and DCI messages can also be used as response messages. Upon receiving the response message, the terminal device determines that the on-demand SSB transmission for the secondary cell sent to the primary cell's base station has been successful, and therefore does not need to resend the SSB transmission request. This prevents repeated transmission requests. It should be noted that the terminal device performs this on-demand SSB measurement, for example, based on pre-notified secondary cell SSB transmission settings. Furthermore, the terminal device may repeatedly send on-demand SSB transmission requests to the primary cell's base station even without receiving a response message. It should be noted that the primary cell's base station may also notify the terminal device of an upper limit set for the number of repeated transmissions of this request. If the terminal device reaches this upper limit after repeatedly sending the request without receiving a response message, it can stop sending the request.

[0062] Furthermore, to prevent on-demand SSB transmission requests related to the same secondary cell from arriving in parallel from multiple terminal devices, the base station of the primary cell can notify multiple terminal devices simultaneously, either on a cell-by-cell or group-by-group basis, of the on-demand SSB transmission request in the secondary cell. For example, the base station of the primary cell can set a specific RNTI corresponding to the on-demand SSB request and notify multiple terminal devices of this RNTI in advance. Moreover, the base station of the primary cell includes the SSB index of the transmitted on-demand SSB in the DCI and transmits it. The multiple terminal devices that have been notified of the aforementioned RNTI can determine the SSB index of the transmitted on-demand SSB by demodulating the DCI using the RNTI. Furthermore, these multiple terminal devices do not request the transmission of the on-demand SSB with the determined SSB index. This prevents multiple terminal devices from transmitting on-demand SSB transmission requests in parallel. It should be noted that if a terminal device receives this information while performing processing for transmitting a transmission request and before it is completed, it can interrupt (terminate) the currently executing processing.

[0063] Here, in Figure 4 This document provides a general example of a processing flow related to an on-demand SSB transmission request. It should be noted that this process can be modified in various ways as described above or later, but only a general processing flow is described here without mentioning such modifications. In this process, the base station device of the primary cell sends an on-demand SSB transmission request to the base station device of the secondary cell (S403). It should be noted that the base station device of the primary cell can send the transmission request to the base station device of the secondary cell upon receiving the on-demand SSB transmission request from the terminal device (S401). Upon receiving the on-demand SSB transmission request from the terminal device, the base station device of the primary cell can send a response message to the terminal device (S402) to prevent repeated transmission of the on-demand SSB transmission request from the terminal device. Additionally, the base station device of the primary cell sends a notification to the terminal device containing configuration information for receiving the on-demand SSB transmitted from the base station device of the secondary cell (S404). It should be noted that this notification can also be included in the response message of S402. The terminal device performs settings for measurement based on this notification (S405). Furthermore, the terminal device can measure the SSBs sent from the base station device of the secondary cell (S406) and send a report of the measurement results to the base station device of the primary cell (S407). After the terminal device completes the measurement of the on-demand SSBs, the base station device of the primary cell can notify the base station device of the secondary cell that the transmission of SSBs should be suppressed or can be suppressed (S408).

[0064] It should be noted that the base station of the primary cell can also reject the on-demand SSB transmission request when it receives it from the terminal device, but there are other secondary cells that do not suppress SSB transmission, and the signal strength or signal quality in the terminal device for that secondary cell is above a predetermined threshold. It should also be noted that if the secondary cell is not activated for the terminal device, the base station of the primary cell can send a MACCE to the terminal device to activate the secondary cell. Furthermore, the base station of the primary cell can also notify the terminal device in the MACCE that the on-demand SSB transmission request has been rejected. Additionally, if the secondary cell has not been configured for the terminal device (not added as a secondary cell for the terminal device), the base station of the primary cell can use an RRC message (e.g., an RRC reconfiguration message) to notify the terminal device of the addition of the secondary cell and, in that message, notify the terminal device that the on-demand SSB transmission request has been rejected.

[0065] When a terminal device sends a request to the base station of the primary cell to transmit an on-demand SSB of a secondary cell that has been suppressed, using a PRACH (random access preamble), it can determine that the transmission request has been accepted based on receiving a random access response from the base station of the primary cell. It should be noted that the terminal device may repeatedly send the random access preamble, for example, if it does not receive a random access response during the expected period (ra-ResponseWindow). It should also be noted that if the terminal device does not receive a random access response even after repeatedly sending the random access preamble until the upper limit (the upper limit of PREAMBLE_TRANSMISSION_COUNTER) is reached, it will stop sending the on-demand SSB. The terminal device may also send a notification related to the failure of the on-demand SSB transmission request to the base station of the primary cell. Upon receiving this notification from the terminal device, the base station of the primary cell may also instruct the terminal device to add or activate other secondary cells.

[0066] <Determination of Suppressed SSB Transmission> Regarding the measurement of the secondary cell (serving cell) used in communication, suppose that the Measobject associated with the information element ServingCellMO contains ssb-configmobility, and the rstype set in reportconfig is SSB. In this case, the measurement mode of ssb-configmobility of the measobject associated with the SSB configuration mode information of the secondary cell can be set, and the terminal device can be notified. Furthermore, if the SSB configuration mode information of the secondary cell is changed, the measurement mode of ssb-configmobility of the measobject is also changed. That is, the measurement mode can be set in a way that prevents SSBs that have stopped transmitting due to suppression from being measured. The change indication of this measurement mode can be indicated using a message with the same SSB configuration mode or a message with a different SSB configuration mode, and the terminal device can be notified. In one example, any one of RRC messages, MAC CE, and DCI can be used to notify the terminal device of the change in measurement-related parameters. That is, when measuring secondary cells (neighboring cells) and the measobject includes SSB-configmobility, the base station device of the primary cell can set the SSB measurement mode in a manner associated with the SSB setting mode in the secondary cell, and notify the terminal device of this measurement mode information. It should be noted that if the SSB setting mode in the secondary cell is changed, the base station device of the primary cell can change the SSB measurement mode according to the changed setting mode and notify the terminal device.

[0067] In one example, the base station device of the primary cell can generate configuration information (measconfig) containing parameters related to the measurement of each secondary cell, matching the configuration mode information of the SSBs in the secondary cell, and notify the terminal device of the generated configuration information. For example, it might be configured such that, before SSB transmission is suppressed, the SMTC window is set to 2ms and the measurement gap length (MGL) to 4ms. This state is then displayed. Figure 5 .exist Figure 5 In this context, SSB#0 to SSB#3 correspond, for example, to SSBs with SSB indices 0 to 3, and this usage will continue in the following cases. Figure 5 In this context, the SMTC window is set to include the transmission timing of SSBs #0 to #3. It should be noted that the actual measurement is performed during the period encompassing the SMTC window (…). Figure 5The measurement is performed within a 3ms interval. Additionally, periods of no transmission or reception are set before and after the actual measurement period, and the MGL is set as the length of this period. Here, when some SSB transmissions are stopped and no measurement is required, the measurement period can be shortened, i.e., the SMTC window length and MGL can be shortened. For example, when SSB#3 transmission is stopped, SMTC window can be set to 2ms, MGL to 4ms or 3.5ms. It should be noted that SMTC window can also be set to 1.5ms. Furthermore, when SSB#2 and SSB#3 transmissions are stopped, SMTC window can be set to 1ms, MGL to 3ms; when SSB#1 to SSB#3 transmissions are stopped, SMTC window can be set to 1ms or 0.5ms, MGL to 3ms or 2.5ms. Information indicating this setting can be notified to the terminal device from the base station device of the main cell. Additionally, the SMTC window period (measurement gap repetition period (MGRP)) can be changed, for example, when using... Figure 2B In the setup mode shown, even with a setting of MGRP of 20ms, a large number of SMTC windows may not be measured. Therefore, settings such as MGRP=160ms or 320ms can be used. It should be noted that multiple measurement parameters (or combinations thereof) such as SMTC windows, MGL, and MGRP can be prepared in advance, each assigned a separate index, and the terminal device can be notified, allowing the actual measurement parameters to be specified via the index.

[0068] It should be noted that the base station equipment in the primary cell can notify the terminal device of the measurement results report configuration in the same way as before. Generally, measurement results are reported in two ways: periodic reports and event trigger reports. When using event trigger reports, the terminal device reports the measurement results to the base station equipment when it determines that a predefined event has occurred. Additionally, the terminal device can also execute pre-set specific processing when it determines that an event has occurred. On the other hand, when using periodic reports, there may be cases where SSBs are not transmitted in secondary cells without SSBs, thus preventing the acquisition of measurement results. In such cases, the terminal device can stop or interrupt the transmission of periodic reports. Furthermore, the terminal device can also send measurement reports to the base station that are not only related to such untransmitted SSBs. Additionally, the terminal device can also report to the base station in the measurement reports regarding untransmitted SSBs in secondary cells without SSBs that the SSB was not detected.

[0069] Suppression of SSB transmission in a secondary cell without SSB> A base station device in a secondary SSB-less cell can directly receive on-demand SSB transmission requests from a terminal device. In this case, the base station device in a secondary SSB-less cell transmits the SSB with the requested SSB index, and can continue suppressing the transmission of other SSBs if this suppression is achieved. Upon receiving an on-demand SSB transmission request without specifying an SSB index, the base station device in a secondary SSB-less cell can end all SSB transmission suppression and begin normal operation. However, this is just one example; the base station device in a secondary SSB-less cell can also end all SSB transmission suppression and begin normal operation upon receiving an on-demand SSB transmission request related to any particular SSB. Furthermore, the base station device in a secondary SSB-less cell can end SSB transmission suppression and begin normal operation upon receiving a predetermined request (e.g., an on-demand SSB transmission request related to a specific SSB or a cell-wide activation request) from the base station device in the primary cell. It should be noted that when a base station device in a secondary SSB-less cell receives a pre-defined request for an SSB with a specific SSB index, it can either transmit the SSB without suppressing it and continue suppressing transmissions for other SSBs, or it can release the suppression for all SSBs. It should also be noted that the base station device in a secondary SSB-less cell can send a response message to the device that sent the request message, such as the on-demand SSB transmission request. For example, when the base station device in a secondary SSB-less cell receives an on-demand SSB transmission request from a terminal device, it can send a pre-defined response message to that terminal device to prevent the transmission request from being repeatedly sent. Furthermore, when the base station device in a secondary SSB-less cell receives the aforementioned pre-defined request from the base station device of the primary cell, it can return a response message to that primary cell's base station device. It should be noted that the response message can be sent either after or before the on-demand SSB transmission begins.

[0070] Each cell's base station equipment can, based on the cell's traffic volume provided by the equipment and location information that determines the location of the terminal device within the cell, initiate the transmission suppression of some or all SSBs in that cell. Additionally, when initiating the transmission of CSI-RS in a specific direction, the base station equipment can also suppress the transmission of SSBs (SSBs with a predetermined QCL Type set between them and the transmitted CSI-RS) in that direction. Furthermore, when the primary cell's base station equipment deactivates a secondary cell activated for a terminal device, it can determine whether the transmission of some or all SSBs in that secondary cell should be suppressed. For example, if the terminal device that activated that secondary cell no longer exists, the primary cell's base station equipment can determine that at least some SSBs in that secondary cell should be suppressed. Furthermore, if there is no longer a terminal device using a specific beam of a specific secondary cell, the primary cell's base station equipment can also determine that the transmission of SSBs corresponding to that specific beam should be suppressed. Furthermore, when the base station of the primary cell receives a report from the terminal device regarding the measurement results of the signal strength or signal quality of the secondary cell, it can determine whether to suppress the transmission of SSBs in the secondary cell based on the measurement results. For example, if the signal strength or signal quality of a specific secondary cell meets the conditions of Event A2 and Event A6 as described above, the base station of the primary cell may not delete the secondary cell but decide whether to suppress the transmission of at least a portion of the SSBs in the secondary cell based on whether the secondary cell is being used by other terminal devices and / or whether there is a possibility of it being used.

[0071] The terminal device can, as described above, request on-demand SSB transmission from the base station of a secondary cell with suppressed SSB transmission, and establish time / frequency synchronization or measure radio quality based on the SSB transmitted according to the request. Here, when the terminal device requests on-demand SSB transmission to establish synchronization, it can, after establishing synchronization according to the request, report to the base station of the primary cell, for example, that synchronization has been established or that no further SSB transmission is needed. This report can be sent, for example, using a message such as UE assistance information. Upon receiving this report, the base station of the primary cell can instruct the base station of the secondary cell to restart SSB transmission suppression. Alternatively, such a report can be sent directly to the base station of the secondary cell, which, upon receiving the report, restarts SSB transmission suppression. Furthermore, for example in… Figure 2D , Figure 2EIn a configuration mode where only SSBs for a portion of beams are transmitted, while SSB transmission for other beams is stopped, as shown, if a terminal device requests on-demand SSB transmission for the beam whose SSB transmission is stopped, it can also stop SSB transmission for the currently transmitting beam. That is, the beam whose SSB transmission is stopped can be reselected. In one example, when the base station of the primary cell receives a request for on-demand SSB transmission for a beam whose SSB transmission is stopped, it can send a message to the base station of the secondary cell without an SSB forming that beam, recommending the suppression of SSB transmission in the currently transmitting beam. Upon receiving this message, the base station of the secondary cell without an SSB can decide whether to suppress SSB transmission in the currently transmitting beam.

[0072] It should be noted that the base station device can use Cell DTX / DRX to set the periods for stopping transmission and reception. Here, in Rel-18 Cell DTX, no signal transmission occurs during inactive periods, but the objects not transmitted are limited to the UE's inherent channels / signaling; instead, SSB transmission occurs. Conversely, for example, in a secondary cell without SSBs, SSB transmission can be stopped during inactive periods and transmitted during active periods, thereby suppressing SSB transmission. Alternatively, a portion of SSB transmission can be suppressed regardless of whether it is an inactive or active period. For example, Figure 6A This illustrates the relationship between the active / inactive period of Cell DTX and the timing of SSB transmission, based on the Rel-18 specification. It should be noted that the period for SSB transmission is represented by a shaded rectangle. Figure 6A As shown, according to the Rel-18 specification, SSBs are sent periodically regardless of whether the previous Cell DTX was active or inactive. Figure 6B An example is shown where SSB transmission is suppressed regardless of whether the Cell DTX is active or inactive. In this example, SSBs are also transmitted during the inactive period of the Cell DTX, but the transmission frequency of the SSBs is suppressed. Figure 6C An example is shown where SSB transmission is suppressed in conjunction with the active / inactive periods of Cell DTX. In this example, SSB transmission is performed during the active period of Cell DTX, and SSB transmission is stopped during the inactive period. This further reduces power consumption during the inactive period. Additionally, as... Figure 6D As shown, it can also be Figure 6B and Figure 6C Combination. That is, it can also be made Figure 6BSSBs whose transmission frequency is suppressed will not be transmitted during inactive periods. Alternatively, CellDTX / DRX can be configured such that an inactive period is set during the period when SSB transmission is stopped, and an active period is set during the period when SSB transmission is conducted.

[0073] <Notifications related to SSB sending suppression> The base station apparatus of the primary cell and the secondary cell without SSB can choose not to notify the terminal device of the situation where SSB transmission is suppressed. That is, SSB transmission can be suppressed without notifying the terminal device. Alternatively, the base station apparatus of the primary cell can, for example, use a MAC CE indicating the deactivation of the secondary cell to notify the terminal device of the situation where SSB transmission is suppressed in that secondary cell. Furthermore, the base station apparatus of the primary cell can use a DCI to notify the terminal device of the situation where at least a portion of SSB transmission is suppressed in a specific secondary cell. In one example, the base station apparatus of the primary cell can use a DCI to notify the terminal device, on a cell-by-cell basis, of the situation where at least a portion of SSB transmission is suppressed in a specific secondary cell for terminal devices belonging to multiple cells. Alternatively, terminal devices can be grouped using predetermined rules, each group can be pre-assigned an RNTI, and the terminal devices belonging to that group can be notified of the situation where SSB transmission is suppressed in a specific secondary cell using a DCI scrambled with that RNTI.

[0074] exist Figure 7 The diagram illustrates a hardware configuration example of the base station device and terminal device according to this embodiment. In one example, the base station device and terminal device are configured to include a processor 701, a ROM 702, a RAM 703, a storage device 704, and a communication circuit 705. The processor 701 is configured as a computer including one or more processing circuits such as a general-purpose CPU (Central Processing Unit) and an ASIC (Application-Specific Integrated Circuit). It performs overall device control processing and the aforementioned processing by reading and executing programs stored in the ROM 702 and the storage device 704. The ROM 702 is a read-only memory that stores programs related to processing executed by the base station device and the terminal device, as well as various parameters and other information. The RAM 703 functions as a working area when the processor 701 executes programs and also stores temporary information in a random access memory. The storage device 704 is, for example, a removable external storage device. The communication circuit 705 is, for example, a wireless communication circuit for 5G and subsequent standards. It should be noted that in Figure 7The diagram illustrates a communication circuit 705, but the base station device and the terminal device can have multiple communication circuits. For example, the base station device and the terminal device can have wireless communication circuits for various standards used in 5G and subsequent standards, and an antenna common to these circuits. It should be noted that the base station device and the terminal device can also each have an antenna suitable for each standard. Additionally, the base station device can also have a wired communication circuit used for communicating with other base station devices and nodes in the core network. Furthermore, the terminal device can also have communication circuits for wireless communication standards other than cellular communication standards, such as wireless local area networks (LAN) and Bluetooth (registered trademark). It should be noted that the base station device and the terminal device can have separate communication circuits 705 for multiple usable frequency bands, or they can have a common communication circuit 705 for at least a portion of these frequency bands.

[0075] Figure 8 This illustrates an example of the functional configuration of a terminal device. For example, the terminal device includes a setting information receiving unit 801, a setting measurement unit 802, a measurement unit 803, an on-demand SSB request unit 804, and a reporting unit 805. It should be noted that... Figure 8 Only functions particularly relevant to this embodiment are shown in the illustrations; other various functions that the terminal device may have are omitted. For example, the terminal device naturally possesses other functions generally found in terminal devices conforming to 5G and subsequent standards. Furthermore, the terminal device may also have functions for performing the various modifications described above. Figure 8 The functional blocks are shown in general terms; each functional block can be implemented as a whole or further subdivided. Additionally, Figure 8 The various functions can be implemented, for example, by the processor 701 executing programs stored in ROM 702 and storage device 704, or by the processor inside the communication circuit 705 executing predetermined software. It should be noted that the details of the processing performed by each functional unit are as described above; therefore, only a general overview of the terminal device's functions is provided here.

[0076] The setting information receiving unit 801 receives various setting information as described above, for example, from the base station device of the primary cell (or, depending on the situation, from the base station device of the secondary cell). The setting information includes, for example, information enabling measurement settings such as setting mode information in a secondary cell without SSB, and information such as the period for requesting on-demand SSBs. Details are as described above and will not be repeated here. The measurement setting unit 802 holds the setting information received in the setting information receiving unit 801 and, for example, performs SSB measurement settings based on identification information subsequently received for specifying setting mode information. The measurement unit 803 uses the measurement settings of the measurement setting unit 802 to perform SSB measurement. The on-demand SSB request unit 804 sends a transmission request to the base station device of the primary cell for SSBs that are suppressed (stopped) in a secondary cell without SSBs. The reporting unit 805 notifies the base station device of the primary cell of the measurement results from the measurement unit 803.

[0077] Figure 9 This illustrates an example of the functional configuration of a base station device for a primary cell. For example, the base station device for a primary cell includes a configuration information notification unit 901, a report receiving unit 902, and an on-demand SSB request unit 903. It should be noted that... Figure 9 Only functions particularly relevant to this embodiment are shown; other various functions that the base station device of the main cell may have are omitted from the illustrations. For example, the base station device of the main cell naturally has other functions generally present in base station devices conforming to 5G and subsequent standards. Furthermore, the base station device may also have functions for performing the various modifications described above. Figure 9 The functional blocks are shown in general terms; each functional block can be implemented as a whole or further subdivided. Additionally, Figure 9 The various functions can be implemented, for example, by the processor 701 executing programs stored in ROM 702 and storage device 704, or by the processor located inside the communication circuit 705 executing predetermined software. It should be noted that the details of the processing performed by each functional unit are as described above; therefore, only a general overview of the base station device's functions is provided here.

[0078] The configuration information notification unit 901 sends various configuration information, such as the one described above, to the connected terminal device. The report receiving unit 902 receives a report from the terminal device on the measurement results of the SSB signal strength or signal quality, etc., based on the configuration information notified by the configuration information notification unit 901. The on-demand SSB request unit 903 requests the transmission of SSBs that have been suppressed (stopped) from the secondary cell without an SSB.

[0079] It should be noted that the above explanation describes the processing related to on-demand SSB transmission in secondary cells of carrier aggregation. Conversely, the same processing can also be performed, for example, when using dual connectivity.

[0080] As described above, in this embodiment, on-demand SSBs in secondary cells of carrier aggregation can be appropriately utilized. Therefore, it is possible to contribute to Goal 9 of the UN-led Sustainable Development Goals (SDGs): “Building resilient infrastructure, promoting sustainable industrialization and fostering innovation.”

[0081] This invention is not limited to the embodiments described above, and various modifications and alterations can be made within the scope of the spirit of this invention.

[0082] This application claims priority based on Japanese Patent Application No. 2024-060368, filed on April 3, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A terminal device that conforms to the 3rd Generation Partnership Project (3GPP) cellular communication standard, wherein, The terminal device has: The receiving unit receives from the base station device of the primary cell providing carrier aggregation a second setting information that differs from the first setting information in the case where the transmission of the synchronization signal (SS) / physical broadcast channel (PBCH) block, i.e., SSB, in the secondary cell is not suppressed, and where at least a portion of the SSB is not transmitted. The setting unit sets the SSB measurement in the secondary cell based on the second setting information; as well as A measurement unit that uses the measurement settings to measure the SSB transmitted in the secondary cell.

2. The terminal device according to claim 1, wherein, The first setting information and the second setting information are respectively assigned corresponding identification information. After receiving the first setting information and the second setting information, the receiving unit also receives, from the base station device, either the identification information of the first setting information or the identification information of the second setting information. When the setting unit receives the identification information of the first setting information, it performs the measurement setting based on the first setting information; when it receives the identification information of the second setting information, it performs the measurement setting based on the second setting information.

3. The terminal device according to claim 1, wherein, In cases where at least a portion of the SSB in the secondary cell is not transmitted, there are multiple second setting information settings for multiple modes of transmitting the SSB, each of which is assigned identification information. After receiving the plurality of second setting information and the identification information of each of the plurality of second setting information, the receiving unit also receives the identification information of any one of the plurality of second setting information. The setting unit performs the measurement setting corresponding to the pattern of the second setting information determined by the identification information.

4. The terminal device according to claim 2 or 3, wherein, The receiving unit receives multiple setting information including the first setting information and the second setting information via Radio Resource Control (RRC) messages, and receives the identification information via Media Access Control-Control Element (MAC CE) or Downlink Control Information (DCI).

5. The terminal device according to claim 1, wherein, The terminal device further includes a transmitting unit, which sends a request to the base station device to transmit at least a portion of the untransmitted SSBs in the secondary cell. The receiving unit receives from the base station device configuration information for determining the SSB sent in the secondary cell according to the request. The setting unit uses this setting information to perform measurement settings.

6. The terminal device according to claim 5, wherein, The receiving unit also receives from the base station device information indicating the period during which the request can be sent. The sending unit sends the request to the base station device during the period.

7. The terminal device according to claim 6, wherein, The receiving unit also receives a response message for the request from the base station device. If the sending unit does not receive the response message, it repeatedly sends the request to the base station device.

8. A base station apparatus that conforms to the 3rd Generation Partnership Project (3GPP) cellular communication standard, wherein, The base station device has: A providing unit that provides the primary cell for carrier aggregation to the terminal devices in the connection; as well as The transmitting unit transmits to the terminal device second setting information that differs from the first setting information in the case where the transmission of the synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) in the secondary cell of the carrier aggregation is not suppressed, and in the case where at least a portion of the SSB is not transmitted.

9. The base station apparatus according to claim 8, wherein, The first setting information and the second setting information are respectively assigned corresponding identification information. After sending the first setting information and the second setting information, the sending unit also sends identification information corresponding to the setting information currently in use in the first setting information and the second setting information to the terminal device.

10. The base station apparatus according to claim 8, wherein, In cases where at least a portion of the SSB in the secondary cell is not transmitted, there are multiple second setting information settings for multiple modes of transmitting the SSB, each of which is assigned identification information. After sending the plurality of second setting information, the sending unit also sends identification information corresponding to the setting information currently in use among the plurality of second setting information to the terminal device.

11. The base station apparatus according to claim 9 or 10, wherein, The transmitting unit transmits multiple configuration information including the first configuration information and the second configuration information via Radio Resource Control (RRC) messages, and transmits the identification information via Media Access Control-Control Element (MAC CE) or Downlink Control Information (DCI).

12. The base station apparatus according to claim 8, wherein, The base station device further includes a receiving unit that receives from the terminal device a transmission request for at least a portion of the untransmitted SSBs in the secondary cell. The transmitting unit sends configuration information to the terminal device for determining the SSB to be transmitted in the secondary cell according to the request.

13. The base station apparatus according to claim 12, wherein, The sending unit also sends information to the terminal device indicating the period during which the request can be sent.

14. The base station apparatus according to claim 13, wherein, The sending unit also sends a response message to the terminal device in response to the request.

15. A control method performed by a terminal device conforming to the 3rd Generation Partnership Project (3GPP) cellular communication standard, wherein, The control method includes: The base station device of the primary cell providing carrier aggregation receives a second setting information that differs from the first setting information in which the transmission of the synchronization signal (SS) / physical broadcast channel (PBCH) block, i.e., SSB, in the secondary cell is not suppressed, and the transmission of at least a portion of the SSB is not performed. The SSB measurement settings in the secondary cell are made based on the second setting information; as well as The aforementioned measurement settings are used to measure the SSB transmitted in the secondary cell.

16. A control method executed by a base station device conforming to the 3rd Generation Partnership Project (3GPP) cellular communication standard, wherein, The control method includes: Provide the primary cell for carrier aggregation to the terminal devices in the connection; and Sending to the terminal device second setting information that differs from the first setting information in the case where the transmission of the synchronization signal (SS) / physical broadcast channel (PBCH) block (SSB) in the secondary cell of the carrier aggregation is not suppressed, and in the case where at least a portion of the SSB is not transmitted.

17. A program in which, The program is used to enable the computer on the terminal device to execute the control method of claim 15.

18. A program in which, The program is used to enable the computer in the base station device to execute the control method of claim 16.

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