Terminal and communication method

Abstract

This terminal comprises: a reception unit which receives an instruction for validating a secondary cell from a base station in a cell other than the secondary cell; and a control unit which assumes, on the basis of the characteristics applicable to the secondary cell, that a delay until the secondary cell is validated after the instruction has been received is shortened.

Description

[Technical field]

[0001] The present invention relates to a terminal and a communication method in a wireless communication system. [Background technology]

[0002] For NR (New Radio) (also known as "5G"), the successor system to LTE (Long Term Evolution), technologies are being considered that satisfy the requirements of a large-capacity system, high-speed data transmission speed, low latency, simultaneous connection of a large number of terminals, low cost, low power consumption, etc. (e.g., Non-Patent Document 1).

[0003] In NR Release 17, a mechanism for efficient activation and deactivation of secondary cell groups and secondary cells is being considered in MR-DC (Multi-RAT Dual-Connectivity). For example, the mechanism for secondary cell groups applied to (NG)EN-DC ((NG-RAN) E-UTRA-NR Dual Connectivity) and NR-DC (NR-NR Dual Connectivity) is being considered. The mechanism for secondary cells applied to NR-CA (NR Carrier aggregation) is also being considered. The mechanism is applied to FR1 (Frequency range) and FR2. It is also being considered to support the change and addition of primary secondary cell group cells. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V16.2.0(2020-07) Summary of the Invention [Problem to be solved by the invention]

[0005] When a terminal operates in carrier aggregation, it can disable a secondary cell to reduce power consumption. When activating a disabled secondary cell, a secondary cell activation delay is required. Here, depending on the period of the synchronization signal, the secondary cell activation delay may become large, resulting in a large delay.

[0006] The present invention has been made in consideration of the above-mentioned points, and has an object to reduce delays when activating a secondary cell in a wireless communication system. [Means for solving the problem]

[0007] According to the disclosed technology, a receiving unit receives an instruction to activate a secondary cell from a base station in a cell other than the secondary cell; ,before The time from receiving the instruction to enabling the secondary cell Calculating a first time period and enabling the secondary cell after the calculated first time period has elapsed. Control unit and 、 Have The control unit calculates a second time period shorter than the first time period based on a relationship between a frequency band of the activated cell and a frequency band of the secondary cell, and activates the secondary cell after the calculated second time period has elapsed. A terminal is provided. Effect of the Invention

[0008] According to the disclosed technology, it is possible to reduce delays when activating a secondary cell in a wireless communication system. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of a configuration of a wireless communication system according to an embodiment of the present invention. [Diagram 2] A diagram showing an example of secondary cell activation. [Diagram 3] 1 is a flowchart for explaining an example (1) of secondary cell activation in an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing an example (1) of a cell group in the embodiment of the present invention. [Diagram 5] FIG. 13 is a diagram showing an example (2) of a cell group in the embodiment of the present invention. [Figure 6] FIG. 13 is a diagram showing an example (3) of a cell group in the embodiment of the present invention. [Figure 7] A figure showing an example of secondary cell activation in an embodiment of the present invention. [Figure 8] FIG. 11 is a diagram showing an example (4) of a cell group in the embodiment of the present invention. [Figure 9] FIG. 5 is a diagram showing an example (5) of a cell group in the embodiment of the present invention. [Figure 10] 11 is a flowchart for explaining an example (2) of secondary cell activation in the embodiment of the present invention. [Figure 11] 13 is a flowchart for explaining an example (3) of secondary cell activation in the embodiment of the present invention. [Figure 12] 2 is a diagram illustrating an example of a functional configuration of a base station 10 according to an embodiment of the present invention. [Figure 13] 2 is a diagram illustrating an example of a functional configuration of a terminal 20 according to an embodiment of the present invention. [Figure 14] 2 is a diagram illustrating an example of a hardware configuration of a base station 10 or a terminal 20 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0011] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies are used as appropriate. However, the existing technologies are, for example, existing LTE, but are not limited to existing LTE. In addition, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and systems after LTE-Advanced (e.g., NR) unless otherwise specified.

[0012] In the embodiment of the present invention described below, terms such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), and PUSCH (Physical Uplink Shared Channel) used in existing LTE are used. This is for convenience of description, and similar signals, functions, etc. may be called by other names. In addition, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even if a signal is used in NR, it is not necessarily specified as "NR-".

[0013] Furthermore, in the embodiment of the present invention, the duplexing method may be a time division duplex (TDD) method, a frequency division duplex (FDD) method, or another method (for example, flexible duplex, etc.).

[0014] Furthermore, in the embodiment of the present invention, when radio parameters, etc. are "configured," this may mean that predetermined values ​​are pre-configured, or that radio parameters notified from base station 10 or terminal 20 are configured.

[0015] Fig. 1 is a diagram showing an example of the configuration of a wireless communication system according to an embodiment of the present invention. As shown in Fig. 1, the wireless communication system according to the embodiment of the present invention includes a base station 10 and a terminal 20. Although Fig. 1 shows one base station 10 and one terminal 20, this is an example, and there may be a plurality of each.

[0016] The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminal 20. The physical resources of a wireless signal are defined in a time domain and a frequency domain, and the time domain may be defined by the number of OFDM (Orthogonal Frequency Division Multiplexing) symbols, and the frequency domain may be defined by the number of subcarriers or the number of resource blocks. The base station 10 transmits a synchronization signal and system information to the terminal 20. The synchronization signal is, for example, NR-PSS and NR-SSS. The system information is, for example, transmitted by NR-PBCH and is also called broadcast information. As shown in FIG. 1, the base station 10 transmits a control signal or data to the terminal 20 in DL (Downlink) and receives a control signal or data from the terminal 20 in UL (Uplink). Both the base station 10 and the terminal 20 can transmit and receive signals by performing beamforming. In addition, both the base station 10 and the terminal 20 can apply communication by MIMO (Multiple Input Multiple Output) to DL or UL. In addition, both the base station 10 and the terminal 20 may communicate via a secondary cell (SCell: Secondary Cell) and a primary cell (PCell: Primary Cell) by CA (Carrier Aggregation). Furthermore, the terminal 20 may communicate via a primary cell of the base station 10 and a primary secondary cell group cell (PSCell: Primary Secondary cell group Cell) of another base station 10 by DC (Dual Connectivity).

[0017] The terminal 20 is a communication device equipped with a wireless communication function, such as a smartphone, a mobile phone, a tablet, a wearable terminal, a communication module for M2M (Machine-to-Machine), etc. As shown in Fig. 1, the terminal 20 receives a control signal or data from the base station 10 via DL and transmits a control signal or data to the base station 10 via UL, thereby using various communication services provided by the wireless communication system.

[0018] Here, in NR Release 17, a mechanism for efficient activation and deactivation of secondary cell groups and secondary cells is being considered in MR-DC (Multi-RAT Dual-Connectivity). For example, the mechanism for secondary cell groups applied to (NG)EN-DC ((NG-RAN) E-UTRA-NR Dual Connectivity) and NR-DC (NR-NR Dual Connectivity) is being considered. The mechanism for secondary cells applied to NR-CA (NR Carrier aggregation) is also being considered. The mechanism is applied to FR1 (Frequency range) and FR2. It is also being considered to support the change and addition of primary secondary cell group cells.

[0019] FIG. 2 is a diagram showing an example of secondary cell activation. When a terminal operates in carrier aggregation, the terminal can disable a secondary cell to reduce power consumption. When activating a disabled secondary cell, a secondary cell activation delay as shown in FIG. 2 is required.

[0020] As shown in FIG. 2, in order to activate a secondary cell, the base station 10 transmits a secondary cell activation command (SCell Activation Command) in a cell other than the secondary cell, and the terminal 20 transmits an ACK.

[0021] For example, if a secondary cell enable command is received in slot n under certain conditions, then at time “slot n+T HARQ +T activation_time +T CSI_Reporting " Secondary cells that are enabled by this time start operating in the active state (e.g., reporting CSI).

[0022] T HARQis the time from downlink transmission including a medium access control (MAC)-control element (CE) of a secondary cell activation command to the terminal 20 transmitting an ACK.

[0023] T activation_time is 3 ms corresponding to the MAC-CE UE processing time and RF warmup / retuning time, and T is the time to the first SSB resource after the 3 ms. firstSSB , 2 ms corresponding to the SSB processing time. activation_time This includes the AGC (Auto Gain Control) setting time, etc.

[0024] T CSI_Reporting is composed of the time from the above 2 ms to the CSI measurement resource, the terminal processing time for CSI measurement and reporting, and the time to the CSI reporting resource.

[0025] Here, in NR, the SSB periodicity may be a large value (e.g., 20 ms, 160 ms, etc.), and the secondary cell activation delay may be T firstSSB becomes relatively large, resulting in a large delay.

[0026] On the other hand, there are cases where it is not necessary to perform time and frequency tracking by SSB reception, and in those cases there is room to shorten the secondary cell activation delay.

[0027] For example, when activating a secondary cell, if there are other already activated primary cells, primary secondary cell group cells, or secondary cells, it may be possible to reuse time and frequency synchronization if those already activated cells have common properties with the secondary cell to be activated (e.g., being located in a very close frequency band).

[0028] For example, if a secondary cell has just transitioned from an activated state to a deactivated state, it may be possible to reuse the time and frequency synchronization from the previous activated state.

[0029] For example, immediately after performing RRM (Radio Resource Management) measurement in a certain secondary cell, it may be possible to reuse the time and frequency synchronization used when the RRM measurement was performed.

[0030] So, when activating a secondary cell, if there is a designated cell among the already activated primary cell, primary secondary cell group cells, or secondary cells, a different secondary cell activation delay may be defined or assumed, i.e., the secondary cell activation delay may be shortened by utilizing the information and properties of the already activated cells.

[0031] The different secondary cell activation delay may be, for example, a shorter delay. For example, T activation_time From T firstSSB It may be the time excluding T activation_time From T firstSSB and 2 ms may be subtracted from the reduced value. Furthermore, a short time (for example, about several hundred μs) for AGC processing, RF processing, or the like may be added to the reduced value.

[0032] 3 is a flowchart for explaining an example (1) of secondary cell activation in an embodiment of the present invention. In step S11, terminal 20 receives a secondary cell activation instruction. In the following step S12, terminal 20 determines whether or not there is a cell that has already been designated as an active cell. If there is a cell that has already been designated as an active cell (YES in S12), the process proceeds to step S13, and if there is no cell that has already been designated as an active cell (NO in S12), the process proceeds to step S14.

[0033] In step S13, the terminal 20 assumes a shortened secondary cell activation delay. Meanwhile, in step S14, the terminal 20 assumes a conventional secondary cell activation delay. The conventional secondary cell activation delay may be a secondary cell activation delay that is not shortened.

[0034] The designated cell may be determined based on a signaling or specification from the network, for example, a group (or combination) of cells may be signaled and a different secondary cell activation delay may be specified or assumed when activating a cell in the group as a secondary cell if any cell in the group is activated.

[0035] Fig. 4 is a diagram showing an example (1) of a cell group in an embodiment of the present invention. Fig. 4 shows an example in which a primary cell and a secondary cell #3 are specified as a combination that can reduce delay. When activating the secondary cell #3, the primary cell is always activated, so the terminal 20 may reduce the secondary cell activation delay by using information and properties of the already activated primary cell.

[0036] Fig. 5 is a diagram showing an example (2) of a cell group in an embodiment of the present invention. Fig. 5 shows an example in which secondary cell #2 and secondary cell #3 are specified as a combination capable of reducing delay. When activating secondary cell #3, since there is no activated cell in the combination, terminal 20 may assume a conventional secondary cell activation delay.

[0037] Fig. 6 is a diagram showing an example (3) of a cell group in an embodiment of the present invention. Fig. 6 shows an example in which secondary cell #1 and secondary cell #3 are specified as a combination capable of reducing delay. Since secondary cell #1 is activated when secondary cell #3 is activated, terminal 20 may reduce the secondary cell activation delay by using information and properties of already activated secondary cell #1.

[0038] 7 is a diagram showing an example of secondary cell activation in an embodiment of the present invention. In a cell other than the secondary cell to be activated, a secondary cell activation command is transmitted from the base station 10 to the terminal 20, and an ACK is transmitted from the terminal 20 to the base station 10. The time from the secondary cell activation command to the transmission of the ACK is T HARQ After sending ACK, 3ms, Xms and T CSI_Reporting After the delay, the CSI report is transmitted from the terminal 20 to the base station 10. As shown in FIG. 7, the secondary cell activation delay is T HARQ +3ms+Xms+T CSI_Reporting X may be, for example, the time required for a newly defined AGC, or X may be 0 ms. Furthermore, when no MAC-CE processing time is required, 3 ms may be removed from the secondary cell activation delay.

[0039] Furthermore, a stepped secondary cell activation delay may be specified or assumed. For example, three stages may be specified as the secondary cell activation delay, and information indicating how similar the groups are in information and characteristics may be notified, or information indicating which groups have the same information and characteristics may be notified, or a secondary cell activation delay stage to be assumed may be determined based on the notified information.

[0040] For example, assume that levels 1, 2, and 3 are defined as possible degrees of secondary cell activation delay (having similar information and properties, or having the same many or important pieces of information and properties). The higher the level, the shorter the secondary cell activation delay can be. When level 1 is set, the secondary cell activation delay is X slots, when level 2 is set, the secondary cell activation delay is Y slots, and when level 3 is set, the secondary cell activation delay is Z slots. In this case, X>Y>Z, and for example, X slots may be the same secondary cell activation delay as in the past. Also, for example, level 1 may be a frequency band where cells are far apart, level 2 may be a frequency band where cells are close (for example, adjacent bands), and level 3 may be adjacent frequency bands (for example, adjacent frequency bands within the same band).

[0041] Fig. 8 is a diagram showing an example (4) of a group of cells in an embodiment of the present invention. As shown in Fig. 8, a primary cell and a secondary cell #3 are specified as a delay-reducing combination level 3. Since the primary cell is always enabled, the terminal 20 may assume the secondary cell enable delay to be Z slots.

[0042] Fig. 9 is a diagram showing an example (5) of a group of cells in an embodiment of the present invention. As shown in Fig. 8, the primary cell and the secondary cell #3 are specified as a delay-reducing combination level 1. Since the primary cell is always activated, the terminal 20 may assume the secondary cell activation delay to be X slots.

[0043] Also, for example, if there are activated cells that have similar information and characteristics to the secondary cell to be activated, a different secondary cell activation delay may be specified or assumed.

[0044] For example, if the secondary cell to be activated is in the same band, in a nearby frequency band, or is designated as a co-located cell, the cell may be considered to have similar information and properties. Furthermore, some of the conditions for having similar information and properties (for example, within an X Hz range between the cells) may be notified.

[0045] For example, it may be determined whether the terminal 20 has information and characteristics similar to those of the terminal 20 based on the information obtained (such as RTT (Round trip time) with the cell, path loss, power strength, power quality, etc.). The criteria for this determination may be notified or may be specified in advance.

[0046] For example, whether the terminals 20 have similar information and characteristics may be determined based on whether the hardware used by the terminals 20 is common (or whether it is assumed that the hardware is common). The criteria for this determination may be notified or may be specified in advance. The criteria for this determination may be notified to the base station 10 as the terminal capabilities.

[0047] Furthermore, a stepped secondary cell activation delay may be specified or assumed. For example, a predetermined number of stages may be specified as the secondary cell activation delay, and information indicating how similar the groups are in information and characteristics may be notified, or information indicating which groups have the same information and characteristics may be notified, or a secondary cell activation delay stage to be assumed may be determined based on the notified information.

[0048] 10 is a flowchart for explaining an example (2) of secondary cell activation in an embodiment of the present invention. In step S21, terminal 20 receives a secondary cell activation instruction. In the following step S22, terminal 20 determines whether or not a cell exists whose characteristics are closer to those of an already active cell than a reference cell. If a cell whose characteristics are closer to those of an already active cell exists (YES in S22), the process proceeds to step S23, and if a cell whose characteristics are closer to those of an already active cell does not exist (NO in S22), the process proceeds to step S24.

[0049] In step S23, the terminal 20 assumes a shortened secondary cell activation delay. Meanwhile, in step S24, the terminal 20 assumes a conventional secondary cell activation delay. The conventional secondary cell activation delay may be a secondary cell activation delay that is not shortened.

[0050] For example, during secondary cell activation, different secondary cell activation delays may be defined or assumed based on the time since the previous operation for that secondary cell, i.e., the secondary cell activation delay may be shortened by utilizing information previously obtained from that secondary cell.

[0051] The different secondary cell activation delay may be, for example, a shorter delay. For example, T activation_time From T firstSSB It may be the time excluding T activation_time From T firstSSB and 2 ms may be subtracted from the reduced value. Furthermore, a short time (for example, about several hundred μs) for AGC processing, RF processing, or the like may be added to the reduced value.

[0052] The above-mentioned time lapse from the previous operation regarding the secondary cell may be, for example, the time lapse from the time when the secondary cell transitions from an enabled state to a disabled state, or the time lapse from the time when an RRM measurement or a measurement report is transmitted regarding the secondary cell. Also, the above-mentioned time lapse from the previous operation regarding the secondary cell may be the time lapse from the time when a terminal operation using another SSB or reference signal is performed.

[0053] A criterion (e.g., a threshold) for the time lapse since the previous operation for the secondary cell may be signaled or predefined, and the terminal 20 may assume a conventional secondary cell activation delay if the time lapse has passed since the criterion, and a shorter secondary cell activation delay if the time lapse has not passed since the criterion, i.e., if the time lapse is small, it may be assumed that previous information is available.

[0054] Furthermore, a stepwise secondary cell activation delay may be specified or assumed. For example, a predetermined number of steps may be specified as the secondary cell activation delay, and whether to assume a stepwise secondary cell activation delay may be determined based on the degree of time lapse (e.g., after how many ms, after how many slots, etc.).

[0055] 11 is a flowchart for explaining an example (3) of secondary cell activation in an embodiment of the present invention. In step S31, terminal 20 receives a secondary cell activation instruction. In the following step S32, terminal 20 determines whether the elapsed time from a reference point in time in the secondary cell is less than a threshold value. If a cell with properties similar to those of an already active cell exists (YES in S32), the process proceeds to step S33, and if a cell with properties similar to those of an already active cell does not exist (NO in S32), the process proceeds to step S34.

[0056] In step S33, the terminal 20 assumes a shortened secondary cell activation delay. Meanwhile, in step S34, the terminal 20 assumes a conventional secondary cell activation delay. The conventional secondary cell activation delay may be a secondary cell activation delay that is not shortened.

[0057] In addition, when a secondary cell is activated, if there is a designated cell among the already activated primary cells, primary secondary group cells or secondary cells, a different secondary cell activation delay may be defined or assumed based on the time elapsed since the previous operation for that secondary cell.

[0058] In the above-mentioned embodiment, the operation for shortening the delay when a secondary cell transitions from a disabled state to an enabled state has been described, but the same operation may be applied to the delay when a secondary cell transitions from a disabled state to a dormant state (a state in which the dormant BWP is enabled) to shorten the delay, or the same operation may be applied to the delay when a secondary cell transitions from a dormant state to an enabled state to shorten the delay.

[0059] According to the above-described embodiment, when activating a secondary cell, the terminal 20 can reduce the delay until the secondary cell is activated based on cells having similar characteristics.

[0060] That is, in a wireless communication system, it is possible to reduce the delay when activating a secondary cell.

[0061] (Device configuration) Next, a functional configuration example of the base station 10 and the terminal 20 that execute the processes and operations described above will be described. The base station 10 and the terminal 20 include functions for implementing the above-mentioned embodiments. However, the base station 10 and the terminal 20 may each include only a part of the functions in the embodiments.

[0062] <Base station 10> Fig. 12 is a diagram showing an example of the functional configuration of base station 10 in the embodiment of the present invention. As shown in Fig. 12, base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Fig. 12 is merely an example. The functional divisions and names of the functional units may be any names as long as they can execute the operations related to the embodiment of the present invention.

[0063] The transmitting unit 110 includes a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. The transmitting unit 110 also transmits an inter-network node message to another network node. The receiving unit 120 includes a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, information of a higher layer from the received signal. The transmitting unit 110 also has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, etc. to the terminal 20. The receiving unit 120 also receives an inter-network node message from another network node.

[0064] The setting unit 130 stores preset setting information and various setting information to be transmitted to the terminal 20. The content of the setting information is, for example, settings relating to the activation of the secondary cell of the terminal 20, and the like.

[0065] As described in the embodiment, the control unit 140 performs control related to the activation of a secondary cell. A functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the reception unit 120.

[0066] <Terminal 20> Fig. 13 is a diagram showing an example of a functional configuration of terminal 20 in an embodiment of the present invention. As shown in Fig. 13, terminal 20 has transmitting unit 210, receiving unit 220, setting unit 230, and control unit 240. The functional configuration shown in Fig. 13 is merely an example. The functional divisions and names of the functional units may be any names as long as they can execute the operations related to the embodiment of the present invention.

[0067] The transmitter 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiver 220 wirelessly receives various signals and acquires a higher layer signal from the received physical layer signal. The receiver 220 also has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, and the like transmitted from the base station 10. For example, the transmitter 210 transmits a PSCCH (Physical Sidelink Control Channel), a PSSCH (Physical Sidelink Shared Channel), a PSDCH (Physical Sidelink Discovery Channel), a PSBCH (Physical Sidelink Broadcast Channel), and the like to another terminal 20 as D2D communication, and the receiver 220 receives the PSCCH, the PSSCH, the PSDCH, or the PSBCH, and the like from the other terminal 20.

[0068] The setting unit 230 stores various setting information received from the base station 10 by the receiving unit 220. The setting unit 230 also stores setting information that is set in advance. The content of the setting information is, for example, settings related to the activation of the secondary cell of the terminal 20.

[0069] As described in the embodiment, the control unit 240 performs control related to the activation of the secondary cell. A functional unit related to signal transmission in the control unit 240 may be included in the transmission unit 210, and a functional unit related to signal reception in the control unit 240 may be included in the reception unit 220.

[0070] (Hardware configuration) The block diagrams (FIGS. 12 and 13) used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically combined, or may be realized using two or more devices that are physically or logically separated and directly or indirectly connected (e.g., using wires, wirelessly, etc.) and these multiple devices. The functional blocks may be realized by combining the one device or the multiple devices with software.

[0071] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocation, mapping, assignment, etc. For example, a functional block (component) that performs the function of transmission is called a transmitting unit or a transmitter. In either case, as described above, there is no particular limitation on the method of realization.

[0072] For example, the base station 10, the terminal 20, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 14 is a diagram showing an example of a hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The above-mentioned base station 10 and the terminal 20 may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0073] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the devices shown in the figure, or may be configured to exclude some of the devices.

[0074] Each function in the base station 10 and the terminal 20 is realized by loading a specific software (program) onto hardware such as a processor 1001, a memory device 1002, etc., so that the processor 1001 performs calculations, controls communications by the communication device 1004, and controls at least one of reading and writing of data in the memory device 1002 and the auxiliary memory device 1003.

[0075] The processor 1001 controls the entire computer by running, for example, an operating system. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0076] Moreover, the processor 1001 reads out a program (program code), a software module, data, or the like from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and executes various processes according to the program. As the program, a program that causes a computer to execute at least a part of the operations described in the above-mentioned embodiment is used. For example, the control unit 140 of the base station 10 shown in FIG. 12 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in FIG. 13 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-mentioned various processes have been described as being executed by one processor 1001, they may be executed by two or more processors 1001 simultaneously or sequentially. The processor 1001 may be implemented by one or more chips. The program may be transmitted from a network via a telecommunication line.

[0077] The storage device 1002 is a computer-readable recording medium, and may be configured by at least one of, for example, a Read Only Memory (ROM), an Erasable Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), a Random Access Memory (RAM), etc. The storage device 1002 may also be called a register, a cache, a main memory (primary storage device), etc. The storage device 1002 can store a program (program code), software modules, etc. that are executable to implement a communication method according to an embodiment of the present disclosure.

[0078] The auxiliary storage device 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other suitable medium including at least one of the storage device 1002 and the auxiliary storage device 1003.

[0079] The communication device 1004 is hardware (transmission and reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., in order to realize at least one of, for example, Frequency Division Duplex (FDD) and Time Division Duplex (TDD). For example, a transmission and reception antenna, an amplifier unit, a transmission and reception unit, a transmission line interface, etc. may be realized by the communication device 1004. The transmission and reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated from each other.

[0080] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs output to the outside. The input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0081] In addition, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0082] Furthermore, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), etc., and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0083] (Summary of the embodiment) As described above, according to an embodiment of the present invention, a terminal is provided having a receiving unit that receives an instruction to activate a secondary cell from a base station in a cell other than the secondary cell, and a control unit that shortens and estimates the delay from receiving the instruction to activating the secondary cell based on characteristics applicable to the secondary cell.

[0084] With the above configuration, when activating a secondary cell, the terminal 20 can reduce the delay until the secondary cell is activated based on a cell having similar characteristics. That is, in the wireless communication system, the delay when activating a secondary cell can be reduced.

[0085] When an enabled cell is present in a group of cells having characteristics similar to those of the pre-specified secondary cell, the control unit may reduce and estimate a delay from receiving the instruction to enabling the secondary cell based on the characteristics of the enabled cell. With this configuration, when activating a secondary cell, the terminal 20 can reduce a delay from when the secondary cell is enabled to when the secondary cell is enabled based on cells having characteristics similar to those of the secondary cell.

[0086] When a cell having characteristics similar to those of the pre-specified secondary cell is activated, the control unit may reduce and estimate a delay from receiving the instruction to activating the secondary cell based on the characteristics of the similar cell. With this configuration, when activating a secondary cell, the terminal 20 can reduce a delay from when the secondary cell is activated based on the cell having characteristics similar to that of the pre-specified secondary cell.

[0087] The cells having similar characteristics may be classified into several stages based on the degree of similarity, and the control unit may assume a larger reduction in the delay as the degree of similarity increases. With this configuration, when activating a secondary cell, the terminal 20 can reduce the delay until the secondary cell is activated according to the degree of similarity based on the cells having similar characteristics.

[0088] When the time elapsed since the reference operation of the secondary cell is less than a threshold, the control unit may reduce and estimate a delay from receiving the instruction to activating the secondary cell based on characteristics measured before the reference operation. With this configuration, when activating a secondary cell, the terminal 20 can reduce a delay until the secondary cell is activated according to the elapsed time based on cells having similar characteristics.

[0089] Furthermore, according to an embodiment of the present invention, a communication method is provided in which a terminal executes a reception procedure for receiving an instruction to activate a secondary cell from a base station in a cell other than the secondary cell, and a control procedure for shortening and estimating the delay from receiving the instruction to activating the secondary cell based on characteristics applicable to the secondary cell.

[0090] With the above configuration, when activating a secondary cell, the terminal 20 can reduce the delay until the secondary cell is activated based on a cell having similar characteristics. That is, in the wireless communication system, the delay when activating a secondary cell can be reduced.

[0091] (Supplementary embodiment) Although the embodiment of the present invention has been described above, the disclosed invention is not limited to such an embodiment, and those skilled in the art will understand various modifications, modifications, alternatives, replacements, and the like. Although the description has been given using specific numerical examples to facilitate understanding of the invention, unless otherwise specified, those numerical values ​​are merely examples and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention, and matters described in two or more items may be used in combination as necessary, and matters described in one item may be applied to matters described in another item (as long as there is no contradiction). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operations of multiple functional units may be physically performed by one part, or the operations of one functional unit may be physically performed by multiple parts. The order of the processing procedures described in the embodiment may be changed as long as there is no contradiction. For convenience of the processing description, the base station 10 and the terminal 20 have been described using functional block diagrams, but such devices may be realized by hardware, software, or a combination thereof. The software operated by the processor possessed by the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor possessed by the terminal 20 in accordance with an embodiment of the present invention may each be stored in a random access memory (RAM), flash memory, read only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

[0092] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination of these. Furthermore, the RRC signaling may be called an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0093] Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and other suitable systems, and next-generation systems extended based on these. In addition, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) may be applied.

[0094] The steps, sequences, flowcharts, etc. of each aspect / embodiment described herein may be reordered unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0095] In this specification, a specific operation performed by the base station 10 may be performed by its upper node in some cases. In a network consisting of one or more network nodes having the base station 10, it is clear that various operations performed for communication with the terminal 20 may be performed by at least one of the base station 10 and other network nodes other than the base station 10 (e.g., MME or S-GW, etc., but are not limited to these). Although the above example illustrates a case in which there is one other network node other than the base station 10, the other network node may be a combination of multiple other network nodes (e.g., MME and S-GW).

[0096] The information or signals described in the present disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0097] The input and output information may be stored in a specific location (e.g., memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added to. The output information may be deleted. The input information may be transmitted to another device.

[0098] In the present disclosure, the determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0099] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0100] Additionally, software, instructions, information, etc. may be transmitted or received over a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using wired and / or wireless technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave, etc.), then these wired and / or wireless technologies are included within the definition of transmission media.

[0101] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0102] In addition, the terms described in this disclosure and the terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, a signal may be a message. Also, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0103] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0104] In addition, the information, parameters, etc. described in the present disclosure may be represented using absolute values, may be represented using relative values ​​from a predetermined value, or may be represented using other corresponding information. For example, a radio resource may be indicated by an index.

[0105] The names used for the above-mentioned parameters are not limiting in any way. Moreover, the formulas using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not limiting in any way.

[0106] In the present disclosure, terms such as "base station (BS)", "wireless base station", "base station device", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier", etc. may be used interchangeably. A base station may also be referred to by terms such as a macro cell, a small cell, a femto cell, a pico cell, etc.

[0107] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or a base station subsystem that provides communication services in this coverage.

[0108] In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0109] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0110] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may include a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0111] Furthermore, the base station in the present disclosure may be read as a user terminal. For example, each aspect / embodiment of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between a plurality of terminals 20 (which may be called, for example, D2D (Device-to-Device) or V2X (Vehicle-to-Everything)). In this case, the terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, an uplink channel, a downlink channel, etc. may be read as a side channel.

[0112] Similarly, a user terminal in the present disclosure may be read as a base station. In this case, the base station may be configured to have the functions of the above-mentioned user terminal.

[0113] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in a memory), and the like. In addition, "judgment" and "decision" can include considering resolving, selecting, choosing, establishing, comparing, etc., to be a "judgment" or "decision." In other words, "judgment" and "decision" can include considering some action to be a "judgment" or "decision." In addition, "judgment" can be interpreted as "assuming," "expecting," "considering," etc.

[0114] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0115] The reference signal may be abbreviated as RS (Reference Signal) and may be called a pilot depending on the applicable standard.

[0116] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0117] Any reference to an element using a designation such as "first," "second," etc., used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must precede the second element in some way.

[0118] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0119] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Further, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0120] A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0121] The numerology may be communication parameters that apply to the transmission and / or reception of a signal or channel, such as, for example, at least one of a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), a number of symbols per TTI, a radio frame structure, a particular filtering operation that the transceiver performs in the frequency domain, a particular windowing operation that the transceiver performs in the time domain, etc.

[0122] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) in the time domain. A slot may be a time unit based on numerology.

[0123] A slot may include multiple minislots. Each minislot may be composed of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may be composed of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0124] A radio frame, a subframe, a slot, a minislot, and a symbol each represent a time unit for transmitting a signal. The radio frame, the subframe, the slot, the minislot, and the symbol may each be referred to by a different name.

[0125] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in the existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit expressing the TTI may be called a slot, a minislot, or the like, instead of a subframe.

[0126] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate wireless resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) to each terminal 20 in TTI units. Note that the definition of TTI is not limited to this.

[0127] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) in which a transport block, a code block, a code word, etc. are actually mapped may be shorter than the TTI.

[0128] In addition, when one slot or one minislot is called TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit of scheduling. Also, the number of slots (minislots) constituting the minimum time unit of scheduling may be controlled.

[0129] A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a minislot, a subslot, a slot, etc.

[0130] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length exceeding 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0131] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of the numerology, for example, 12. The number of subcarriers included in an RB may be determined based on the numerology.

[0132] In addition, the time domain of the RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. Each of one TTI, one subframe, etc. may be composed of one or more resource blocks.

[0133] Note that one or more RBs may be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, or the like.

[0134] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0135] A Bandwidth Part (BWP), which may also be referred to as a fractional bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a numerology on a carrier, where the common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0136] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0137] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell", "carrier", etc. in this disclosure may be replaced with "BWP".

[0138] The above-mentioned structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0139] In this disclosure, where articles have been added due to translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0140] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0141] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched according to execution. In addition, notification of specific information (e.g., notification that "X is the case") is not limited to being done explicitly, but may be done implicitly (e.g., not notifying the specific information).

[0142] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure. [Explanation of symbols]

[0143] 10 base station 110 Transmitter 120 Receiving unit 130 Setting section 140 Control section 20 Terminals 210 Transmitter 220 Receiving unit 230 Setting section 240 Control Unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication equipment 1005 Input Device 1006 Output device

Claims

1. A receiving unit that receives an instruction to activate a secondary cell from a base station in a cell other than the secondary cell; a control unit that calculates a first time from receiving the instruction to enabling the secondary cell, and enables the secondary cell after the calculated first time has elapsed; The control unit calculates a second time shorter than the first time based on a relationship between a frequency band of an activated cell and a frequency band of the secondary cell, and activates the secondary cell after the calculated second time has elapsed. A terminal.

2. The terminal according to claim 1 , wherein the control unit calculates a second time period that is shorter than the first time period when the frequency band of the enabled cell and the frequency band of the secondary cell are in the same band.

3. The terminal according to claim 1 , wherein the control unit calculates the first time when the frequency band of the enabled cell and the frequency band of the secondary cell are not identical and not adjacent to each other.

4. A communication method executed by a terminal, comprising: A receiving step of receiving an instruction to activate a secondary cell from a base station in a cell other than the secondary cell; a control procedure of calculating a first time from receiving the instruction to enabling the secondary cell, and enabling the secondary cell after the calculated first time has elapsed; The control procedure calculates a second time period shorter than the first time period based on a relationship between a frequency band of an activated cell and a frequency band of the secondary cell, and activates the secondary cell after the calculated second time period has elapsed.

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