100A while the CHO condition is being monitored by the terminal 200 (S19), the gNB 100A transmits a Conditional HO request (CHO request) to the gNBs 100B and 100C again in accordance with the modification (S21).

In the operation example 1, since the modification of the configuration of the gNB 100A is concerned with the configuration information of each candidate cell, the gNB 100A needs to transmit the Conditional HO request (CHO request) to the gNBs 100B and 100C again. The configuration of the gNB 100A includes bearer config, radio resource config and the like, for example.

If the gNB 100B (candidate cell) allows the terminal 200 to transition to the gNB 100B even after the configuration of the gNB 100A is modified, the gNB 100B transmits to the gNB 100A, a CHO request response (CHO request ACK) which is a positive acknowledgement to the CHO request (S23). The CHO request ACK includes new configuration information of the candidate cell.

Similarly, if the gNB 100C (candidate cell) allows the terminal 200 to transition to the gNB 100C even after the configuration of the gNB 100A is modified, the gNB 100B transmits to the gNB 100A, a CHO request response (CHO request ACK) which is a positive acknowledgement to the CHO request (S23). The CHO request ACK includes new configuration information of the candidate cell.

When the gNB 100A receives the CHO request ACKs from the gNBs 100B and 100C, the gNB 100A transmits RRC Reconfiguration to the terminal 200 after the set of candidate cells is completed (S25). RRC Reconfiguration includes the new configuration information of the candidate cell transmitted from each of the gNBs 100B and 100C.

When the terminal 200 receives RRC Reconfiguration from the gNB 100A again, the terminal 200 obtains the new configuration information of each candidate cell within RRC Reconfiguration. The terminal 200 update the configuration information of each candidate cell as will be described later, and then monitors the transition condition (CHO condition) to each candidate cell based on the new configuration information of each candidate cell.

If the terminal 200 judges that the transition condition to one candidate cell is satisfied due to a movement of the terminal 200 or the like (S27), the terminal 200 determines to start a handover (HO) to the one candidate cell without receiving a handover command from the source gNB 100A. The candidate cell as the transition destination to which the transition condition is satisfied, is also called as a CHO cell. In the present embodiment, the CHO cell is the gNB 100B.

When the terminal 200 determines to start the HO to the one candidate cell, the terminal 200 performs a random access (RA) procedure between the gNB 100B and the terminal 200, and establishes synchronization between the gNB 100B and the terminal 200 (S29). Thereby, the terminal 200 is connected to the gNB 100B.

If the terminal 200 succeeds in the RA procedure, the terminal 200 transmits RRC Reconfiguration Complete to the gNB 100B, for example.

Note that in S13, the gNB 100A can receive only information on a candidate cell from each of the gNBs 100B and 100C. In this case, the gNB 100A sets a transition condition to the candidate cell. Also, in this case, configuration information of the candidate cell includes the information on the candidate cell and the transition condition to the candidate cell set by the gNB 100A.

(3.1.1) Operations of Terminal

Next, operations of the terminal 200 in the operation example 1 of the Conditional HO procedure will be described.

FIG. 5 is a diagram illustrating an operation flow of the terminal 200 in the operation example 1 of the Conditional HO procedure. As illustrated in FIG. 5, the terminal 200 receives new RRC Reconfiguration from the gNB 100A (S41).

When the terminal 200 receives RRC Reconfiguration from the gNB 100A, the terminal 200 updates the configuration information of each candidate cell (S43). Specifically, the terminal 200 deletes the whole configuration information of each candidate cell held, and applies the new configuration information of each candidate cell within RRC Reconfiguration. In this case, the terminal 200 may overwrite the configuration information of each candidate cell held, with the new configuration information of each candidate cell within RRC Reconfiguration.

The terminal 200 may delete RRCReconfigurationList held, and then apply new RRCReconfigurationList within RRC Reconfiguration. In this case, the terminal 200 may overwrite RRCReconfigurationList held, with new RRCReconfigurationList within RRC Reconfiguration.

(3.2) (Operation Example 2)

FIG. 6 is a diagram illustrating a sequence (operation example 2) of the Conditional HO procedure. Since the process contents of S51 to S57, S63 and S65 in FIG. 6 are the same as those of S11 to S17, S27 and S29 in FIG. 3, descriptions of them are omitted.

If the configuration (Source configuration) of the gNB 100A is modified at the gNB 100A while the CHO condition is being monitored by the terminal 200 (S59), the gNB 100A transmits RRC Reconfiguration to the terminal 200 (S61). RRC Reconfiguration includes a modified configuration of the gNB 100A.

In the operation example 2, since the modification of the configuration of the gNB 100A is not concerned with the configuration information of each candidate cell, the gNB 100A does not transmit the Conditional HO request (CHO request) to the gNBs 100B and 100C again. The configuration of the gNB 100A includes measConfig, CHO condition config (Event A3, A5, B1, etc.) and the like, for example.

Event A3 is an event in which a state in which a value of radio quality of a candidate cell is larger than a value obtained by adding an offset to a value of radio quality of a cell where the terminal 200 resides, is measured. Event A5 is an event in which a state in which a value of radio quality of a cell where the terminal 200 resides becomes worse than a threshold 1 and a value of radio quality of a candidate cell becomes better than a threshold 2, is measured. Event B1 is an event in which a state in which a value of radio quality of a candidate cell is larger than a threshold, is measured.

When the terminal 200 receives RRC Reconfiguration from the gNB 100A again, the terminal 200 obtains the modified configuration of the gNB 100A within RRC Reconfiguration.

(3.2.1) Operations of Terminal

Next, operations of the terminal 200 in the operation example 2 of the Conditional HO procedure will be described.

FIG. 7 is a diagram illustrating an operation flow of the terminal 200 in the operation example 2 of the Conditional HO procedure. As illustrated in FIG. 7, the terminal 200 receives new RRC Reconfiguration from the gNB 100A (S71).

When the terminal 200 receives RRC Reconfiguration from the gNB 100A, the terminal 200 updates the configuration (measConfig, CHO condition config, etc.) of the gNB 100A (S73). Specifically, the terminal 200 deletes the configuration of the gNB 100A held, and applies configuration information of the modified configuration of the gNB 100A within RRC Reconfiguration. In this case, the terminal 200 may overwrite the configuration of the gNB 100A held, with the modified configuration of the gNB 100A within RRC Reconfiguration.

(3.3) (Operation Example 3)

In the operation example 3, when the gNB 100A transmits RRC Reconfiguration to the terminal 200 again (S25 in FIG. 3 and S61 in FIG. 6), the gNB 100A transmits to the terminal 200, modification information indicating which of the new configuration information of each candidate cell and the modified configuration of the gNB 100A is included in RRC Reconfiguration. The gNB 100A includes the modification information in RRC Reconfiguration. The gNB 100A may transmit to the terminal 200, the modification information separately from RRC Reconfiguration.

FIG. 8 is a diagram illustrating an operation flow of the terminal 200 in the operation example 3 of the Conditional HO procedure. As illustrated in FIG. 8, the terminal 200 receives new RRC Reconfiguration from the gNB 100A (S81).

When the terminal 200 receives RRC Reconfiguration from the gNB 100A, the terminal 200 obtains the modification information within RRC Reconfiguration. The terminal 200 determines whether the new configuration information (CHO configuration) of each candidate cell is included in RRC Reconfiguration based on the obtained modification information (S83).

If the new configuration information (CHO configuration) of each candidate cell is included in RRC Reconfiguration, the terminal 200 deletes the whole configuration information of each candidate cell held, and then applies the new configuration information of each candidate cell within RRC Reconfiguration (S85). In this case, the terminal 200 may overwrite the configuration information of each candidate cell held, with the new configuration information of each candidate cell within RRC Reconfiguration.

The terminal 200 may delete RRCReconfigurationList held, and then apply new RRCReconfigurationList within RRC Reconfiguration. In this case, the terminal 200 may overwrite RRCReconfigurationList held, with new RRCReconfigurationList within RRC Reconfiguration.

On the other hand, if the new configuration information (CHO configuration) of each candidate cell is not included in RRC Reconfiguration, the terminal 200 deletes the configuration of the gNB 100A held, and then applies configuration information of the modified configuration of the gNB 100A within RRC Reconfiguration (S87). In this case, the terminal 200 may overwrite the configuration of the gNB 100A held, with the modified configuration of the gNB 100A within RRC Reconfiguration.

Others

Although in the operation example 3, the gNB 100A transmits to the terminal 200, the modification information indicating which of the new configuration information of each candidate cell and the modified configuration of the gNB 100A is included in RRC Reconfiguration, the present embodiment is not limited to it.

For example, the gNB 100A may transmit to the terminal 200, modification information indicating which of modified configuration information of a candidate cell within RRCReconfigurationList (that is, modified configuration information of a candidate cell among plural pieces of the configuration information of the candidate cells) and the modified configuration of the gNB 100A is included in RRC Reconfiguration.

In this case, the terminal 200 overwrites only it with the modified configuration information of the candidate cell within RRCReconfigurationList, among the plural pieces of the configuration information of the candidate cells held, in S85.

The gNB 100A may transmit to the terminal 200, modification information indicating which of modified configuration information of a candidate cell within RRCReconfigurationList and updated configuration of the gNB 100A within all configurations of the gNB 100A is included in RRC Reconfiguration.

In this case, the terminal 200 overwrites only it with the updated configuration of the gNB 100A among all configurations of the gNB 100A held, in S87.

(4) Action and Effect

According to the embodiment described above, when the terminal 200 receives modification information indicating whether there is a modification to configuration information of a transition destination cell, the terminal 200 modifies the configuration information of the transition destination cell based on the modification information.

In this configuration, the terminal can reliably update the configuration information of the candidate cell. This allows the terminal to perform an appropriate cell transition.

According to the embodiment, the modification information indicates whether there is a modification to configuration information of each transition destination cell.

In this configuration, it is not necessary for the terminal 200 to update all pieces of the configuration information of the transition destination cells. This saves power of the terminal 200.

(5) Modified Example

The embodiment described above can be applied to a Conditional SCG Change (CSC). Note that the CSC is also called a Conditional PSCell change or a Conditional PSCell addition.

FIG. 9 is an overall schematic configuration diagram of a radio communication system 10a according to the present embodiment. As illustrated in FIG. 9, the NG-RAN (not illustrated) includes radio base stations 110A, 110B, 110C, and 110D (hereinafter, referred to as gNBs 110A, 110B, 110C, and 110D). Note that a specific configuration of the radio communication system 10a including the number of gNBs and the number of terminals is not limited to the example illustrated in FIG. 6.

In NR, cells are classified as follows.

A group of a cell associated with a gNB (which is also called a master node (MN)) that provides a control plane connected to a core network, is called a Master Cell Group (MCG). The MCG includes a primary cell (hereinafter, referred to as PCell) and one or more secondary cells (hereinafter, referred to as SCells). The PCell is a cell in which a terminal starts to perform an initial connection with the MN. Note that the MCG can include only the PCell.

A group of a cell associated with a gNB (which is also called a secondary node (SN)) that provides additional resources to a terminal, without providing the control plane connected to the core network, is called a Secondary Cell Group (SCG). The SCG includes a primary SCell (hereinafter, referred to as PSCell) and one or more SCells. The PSCell is a cell in which a terminal starts to perform an initial connection with the SN. Note that the SCG can include only the PSCell.

Note that the PCell is also called a Special Cell (SpCell) in the MCG. The PSCell is also called the SpCell in the SCG.

In the present embodiment, the gNB 110A is configured as the MN, and the gNBs 110B, 110C and 110D are configured as the SNs. In this case, the terminal 200 is connected to the gNB 110A (MN) and one of the gNBs 110B, 110C and 110D (SNs) and performs DC.

In DC, under a state where the terminal 200 is connected to the gNB 110A (MN), the terminal 200 can transition between cells formed by the gNBs 110B, 110C, and 110D (SNs). Note that the expression “transition between cells formed by the gNBs 110B, 110C, and 110D (SNs)” can be restated as “transition between the PSCells formed by the gNBs 110B, 110C, and 110D (SNs)”, “transition between the gNBs 110B, 110C, and 110D (SNs)” or “transition between the radio base stations 110B, 110C, and 110D”.

The “transition” typically means a handover between cells, or a handover between gNBs, and can include a behavior of the terminal 200 which causes a change of a connection destination cell (PSCell) or a connection destination gNB (SN), such as SN change.

The cell (radio base station) of the transition destination to which the terminal 200 transitions is called a target cell or a target radio base station. Further, an SN of the transition destination to which the terminal 200 transitions is called a target SN. In the present embodiment, the gNB 110C or the gNB 110D is the target SN.

On the other hand, a cell (radio base station) of a transition source is called a source cell or a source radio base station. An SN of the transition source is called a source SN. In the present embodiment, the gNB 110B is the source SN.

In the radio communication system 10a, the terminal 200 performs the SN change called the Conditional SCG change in DC. Note that the Conditional SCG change can be abbreviated as CSC.

Note that the radio communication system 10a may include an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) instead of the NG-RAN. In this case, the E-UTRAN includes a plurality of E-UTRAN nodes, specifically, eNBs (or en-gNBs), and is connected to a core network (EPC) according to LTE.

(5.1) (Operation Example 1)

FIG. 10 is a diagram illustrating a sequence (operation example 1) of the Conditional SCG Change procedure. As illustrated in FIG. 10, the gNB 110A transmits an SN Addition Request to the gNBs 110C and 110D (candidate cells) except for the gNB110B (source cell) (S111).

When the gNB 110C (candidate cell) receives the SN Addition Request from the gNB 110A, the gNB 110C transmits to the gNB 110A, an SN Addition Request response (SN Addition Request ACK) which is a positive acknowledgement to the SN Addition Request (S113). The SN Addition Request ACK includes configuration information of the candidate cell. The configuration information includes information on the candidate cell and a transition condition to the candidate cell.

Similarly, when the gNB 110D (candidate cell) receives the SN Addition Request from the gNB 110A, the gNB 110D transmits to the gNB 110A, an SN Addition Request response (SN Addition Request ACK) which is a positive acknowledgement to the SN Addition Request (S113). The SN Addition Request ACK includes configuration information of the candidate cell. The configuration information includes information on the candidate cell and a transition condition to the candidate cell.

Through this process, the gNBs 110C and 110D are set as candidate cells for the Conditional SCG Change destination of the terminal 200.

When the gNB 110A receives the SN Addition Request ACKs from the gNBs 110C and 110D, the gNB 110A transmits an SN Release Request to the gNB 110B (source cell) after the set of candidate cells is completed (S115). When the gNB 110B receives the SN Release Request, the gNB 110B transmits an SN Release Request ACK to the gNB 110A (MN), stops data transmission to the terminal 200, and releases an SN resource (S117).

When the gNB 110A receives the SN Release Request ACK from the gNB 110B (source cell), the gNB 110A transmits RRC Reconfiguration to the terminal 200 (S119). RRC Reconfiguration includes the configuration information of the candidate cell transmitted from each of the gNBs 110C and 110D. Note that the reception of RRC Reconfiguration is also called reception of a CSC command.

When the terminal 200 receives RRC Reconfiguration from the gNB 110A, the terminal 200 obtains the configuration information of each candidate cell and the configuration of the gNB 110A within RRC Reconfiguration. When the terminal 200 obtains the configuration information of each candidate cell, the terminal 200 monitors the transition condition (CSC condition) to each candidate cell based on the configuration information of each candidate cell (S121). Specifically, the terminal 200 judges whether or not the transition condition to each candidate cell included in the configuration information of each candidate cell is satisfied.

If the configuration (MN configuration) of the gNB 110A is modified at the gNB 110A while the CHO condition is being monitored by the terminal 200 (S123), the gNB 110A transmits an SN Addition Request to the gNBs 110C and 110D again in accordance with the modification (S125).

In the operation example 1, since the modification of the configuration of the gNB 110A is concerned with the configuration information of each candidate cell, the gNB 110A needs to transmit the SN Addition Request to the gNBs 110C and 110D again. The configuration of the gNB 110A includes bearer config, radio resource config and the like, for example.

If the gNB 110C (candidate cell) allows the terminal 200 to transition to the gNB 110C even after the configuration of the gNB 110A is modified, the gNB 110C transmits an SN Addition Request ACK to the gNB 110A (S127). The SN Addition Request ACK includes new configuration information of the candidate cell.

Similarly, if the gNB 110D (candidate cell) allows the terminal 200 to transition to the gNB 110D even after the configuration of the gNB 110A is modified, the gNB 110D transmits an SN Addition Request ACK to the gNB 110A (S127). The SN Addition Request ACK includes new configuration information of the candidate cell.

When the gNB 110A receives the SN Addition Request ACKs from the gNBs 110C and 110D, the gNB 110A transmits RRC Reconfiguration to the terminal 200 after the set of candidate cells is completed (S129). RRC Reconfiguration includes the new configuration information of the candidate cell transmitted from each of the gNBs 110C and 110D.

When the terminal 200 receives RRC Reconfiguration from the gNB 110A again, the terminal 200 obtains the new configuration information of each candidate cell within RRC Reconfiguration. The terminal 200 update the configuration information of each candidate cell as will be described later, and then monitors the transition condition (CSC condition) to each candidate cell based on the new configuration information of each candidate cell.

If the terminal 200 judges that the transition condition to one candidate cell is satisfied due to a movement of the terminal 200 or the like (S131), the terminal 200 determines to start an SN change to the one candidate cell without receiving a command from the gNB 110A. The candidate cell as the transition destination to which the transition condition is satisfied, is also called as a CSC cell. In the present embodiment, the CSC cell is the gNB 110C.

When the terminal 200 determines to start the SN change to the one candidate cell, the terminal 200 performs a random access (RA) procedure between the gNB 110C and the terminal 200, and establishes synchronization between the gNB 110C and the terminal 200 (S133). Thereby, the terminal 200 is connected to the gNB 110C.

If the terminal 200 succeeds in the RA procedure, the terminal 200 transmits RRC Reconfiguration Complete to the gNB 110C, for example.

Note that in S113, the gNB 110A can receive only information on a candidate cell from each of the gNBs 110C and 110D. In this case, the gNB 110A sets a transition condition to the candidate cell. Also, in this case, configuration information of the candidate cell includes the information on the candidate cell and the transition condition to the candidate cell set by the gNB 110A.

Operations of the terminal 200 in the operation example 1 in the Conditional SCG Change procedure are similar to those in (3.1.1) Operations of Terminal described above.

(5.2) (Operation Example 2)

FIG. 11 is a diagram illustrating a sequence (operation example 2) of the Conditional SCG Change procedure. Since the process contents of S151 to S161, S167 and S169 in FIG. 11 are the same as those of S111 to S121, S131 and S133 in FIG. 10, descriptions of them are omitted.

If the configuration (MN configuration) of the gNB 110A is modified at the gNB 110A while the CSC condition is being monitored by the terminal 200 (S163), the gNB 110A transmits RRC Reconfiguration to the terminal 200 (S165). RRC Reconfiguration includes a modified configuration of the gNB 110A.

In the operation example 2, since the modification of the configuration of the gNB 110A is not concerned with the configuration information of each candidate cell, the gNB 110A does not transmit the SN Addition Request to the gNBs 110C and 110D again. The configuration of the gNB 110A includes measConfig, CHO condition config (Event A3, A5, B1, etc.) and the like, for example.

When the terminal 200 receives RRC Reconfiguration from the gNB 110A again, the terminal 200 obtains the modified configuration of the gNB 110A within RRC Reconfiguration.

Operations of the terminal 200 in the operation example 2 in the Conditional SCG Change procedure are similar to those in (3.2.1) Operations of Terminal described above. Further, as operations of the terminal 200 in a modified example of the Conditional SCG Change procedure, the operations of the terminal in (3.3) and (3.4) descried above, can be applied.

The modified example can be also applied when the configuration of the gNB 110B is modified. Even in this case, as described above, it is possible to address separately whether or not a modification to the configuration of the gNB 110B is concerned with the configuration information of the candidate cell.

(6) Other Embodiments

Although the contents of the present invention have been described along with the embodiment, the present invention is not limited to these descriptions, and it will be obvious to those skilled in the art that various modifications and improvements can be made thereto.

For example, in the embodiments described above, NR has been described as an example. However, the Conditional HO and the Conditional SCG Connection are also applicable to LTE, and the same operation may be performed in LTE.

The block configuration diagram (FIG. 2) used for explaining the above-described embodiment illustrates blocks of functional unit. Those functional blocks (structural components) are realized by a desired combination of at least one of hardware and software. A method for realizing each functional block is not particularly limited. That is, each functional block may be realized by one device combined physically or logically. Alternatively, two or more devices separated physically or logically may be directly or indirectly connected (for example, wired, or wireless) to each other, and each functional block may be realized by these plural devices. The functional blocks may be realized by combining software with the one device or the plural devices mentioned above.

Functions include judging, deciding, determining, calculating, computing, processing, deriving, investigating, searching, confirming, receiving, transmitting, outputting, accessing, resolving, selecting, choosing, establishing, comparing, assuming, expecting, considering, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), assigning, and the like. However, the functions are not limited thereto. For example, a functional block (structural component) that causes transmitting is called a transmitting unit or a transmitter. For any of the above, as explained above, the realization method is not particularly limited to any one method.

Furthermore, the terminal 200 explained above may function as a computer that performs the processing of the radio communication method of the present disclosure. FIG. 12 is a diagram illustrating an example of a hardware configuration of the terminal. As illustrated in FIG. 12, the terminal can be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

Furthermore, in the following explanation, the term “device” can be replaced with a circuit, device, unit, and the like. A hardware configuration of the device may be constituted by including one or plurality of the devices illustrated in the figure, or may be constituted by without including a part of the devices.

The functional blocks of the device can be realized by any of hardware elements of the computer device or a desired combination of the hardware elements.

Moreover, the processor 1001 performs operation by loading a predetermined software (program) on hardware such as the processor 1001 and the memory 1002, and realizes various functions of the device by controlling communication via the communication device 1004, and controlling at least one of reading and writing of data on the memory 1002 and the storage 1003.

The processor 1001, for example, operates an operating system to control the entire computer. The processor 1001 can be configured with a central processing unit (CPU) including an interface with a peripheral device, a control device, an operation device, a register, and the like.

Moreover, the processor 1001 reads a program (program code), a software module, data, and the like from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processing according to them. As the program, a program that is capable of executing on the computer at least a part of the operation explained in the above embodiments, is used. Alternatively, various processes explained above may be executed by one processor 1001 or may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 can be implemented by using one or more chips. Alternatively, the program can be transmitted from a network via a telecommunication line.

The memory 1002 is a computer readable recording medium and may configured, for example, with at least one of Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), Random Access Memory (RAM), and the like. The memory 1002 can be called register, cache, main memory (main storage device), and the like. The memory 1002 can store therein a program (program codes), software modules, and the like that can execute the method according to the embodiment of the present disclosure.

The storage 1003 is a computer readable recording medium. Examples of the storage 1003 include at least one of an optical disk such as Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, Blu-ray (Registered Trademark) disk), a smart card, a flash memory (for example, a card, a stick, a key drive), a floppy (Registered Trademark) disk, a magnetic strip, and the like. The storage 1003 can be called an auxiliary storage device. The recording medium can be, for example, a database including at least one of the memory 1002 and the storage 1003, a server, or other appropriate medium.

The communication device 1004 is hardware (transmission and reception device) capable of performing communication between computers via at least one of a wired network and a wireless network. The communication device 1004 is also called, for example, a network device, a network controller, a network card, a communication module, and the like.

The communication device 1004 may include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like in order to realize, for example, at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, and the like) that accepts input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, and the like) that outputs data to the outside. Note that, the input device 1005 and the output device 1006 may be integrated (for example, a touch screen).

In addition, the respective devices, such as the processor 1001 and the memory 1002, are connected to each other with the bus 1007 for communicating information therebetween. The bus 1007 may be constituted by a single bus or may be constituted by separate buses between the devices.

Further, the device may be configured to include hardware such as a microprocessor, a Digital Signal Processor (DSP), Application Specific Integrated Circuit (ASIC), Programmable Logic Device (PLD), and Field Programmable Gate Array (FPGA). Some or all of these functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented by using at least one of these hardware.

Notification of information is not limited to that explained in the above aspect/embodiment, and may be performed by using a different method. For example, the notification of information may be performed by physical layer signaling (for example, Downlink Control Information (DCI), Uplink Control Information (UCI), higher layer signaling (for example, RRC signaling, Medium. Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination of these. The RRC signaling may be called RRC message, for example, or may be RRC Connection Setup message, RRC Connection Reconfiguration message, or the like.

Each of the above aspects/embodiments may be applied to at least one of Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (Registered Trademark), GSM (Registered Trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (Registered Trademark)), IEEE 802.16 (WiMAX (Registered Trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (Registered Trademark), a system using any other appropriate system, and a next-generation system that is expanded based on these. Further, a plurality of systems may be combined (for example, a combination of at least one of the LTE and the LTE-A with the 5G).

As long as there is no inconsistency, the order of processing procedures, sequences, flowcharts, and the like of each of the above aspects/embodiments in the present disclosure may be exchanged. For example, the various steps and the sequence of the steps of the methods explained above are exemplary and are not limited to the specific order mentioned above.

The specific operation that is performed by the base station in the present disclosure may be performed by its upper node in some cases. In a network constituted by one or more network nodes having a base station, the various operations performed for communication with the terminal may be performed by at least one of the base station and other network nodes other than the base station (for example, MME, S-GW, and the like may be considered, but not limited thereto). In the above, an example in which there is one network node other than the base station is explained; however, a combination of a plurality of other network nodes (for example, MME and S-GW) may be used.

Information and signals (information and the like) can be output from a higher layer (or lower layer) to a lower layer (or higher layer). It may be input and output via a plurality of network nodes.

The input and output information can be stored in a specific location (for example, a memory) or may be managed in a management table. The information to be input and output can be overwritten, updated, or added. The information can be deleted after outputting. The inputted information may be transmitted to another device.

The determination may be made by a value (0 or 1) represented by one bit or by Boolean value (Boolean: true or false), or by comparison of numerical values (for example, comparison with a predetermined value).

Each aspect/embodiment described in the present disclosure may be used separately or in combination, or may be switched in accordance with the execution. In addition, notification of predetermined information (for example, notification of “being X”) is not limited to being performed explicitly, it may be performed implicitly (for example, without notifying the predetermined information).

Instead of being referred to as software, firmware, middleware, microcode, hardware description language, or some other name, software should be interpreted broadly to mean instruction, instruction set, code, code segment, program code, program, subprogram, software module, application, software application, software package, routine, subroutine, object, executable file, execution thread, procedure, function, and the like.

Further, software, instruction, information, and the like may be transmitted and received via a transmission medium. For example, when a software is transmitted from a website, a server, or some other remote source by using at least one of a wired technology (coaxial cable, optical fiber cable, twisted pair, Digital Subscriber Line (DSL), or the like) and a wireless technology (infrared light, microwave, or the like), then at least one of these wired and wireless technologies is included within the definition of the transmission medium.

Information, signals, or the like mentioned above may be represented by using any of a variety of different technologies. For example, data, instruction, command, information, signal, bit, symbol, chip, or the like that may be mentioned throughout the above description may be represented by voltage, current, electromagnetic wave, magnetic field or magnetic particle, optical field or photons, or a desired combination thereof.

Note that the terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced by 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. Further, a component carrier (CC) may be referred to as a carrier frequency, a cell, a frequency carrier, or the like.

The terms “system” and “network” used in the present disclosure can be used interchangeably.

Furthermore, the information, the parameter, and the like explained in the present disclosure can be represented by an absolute value, may be expressed as a relative value from a predetermined value, or may be represented by corresponding other information. For example, the radio resource may be instructed by an index.

The name used for the above parameter is not a restrictive name in any respect. In addition, formulas and the like using these parameters may be different from those explicitly disclosed in the present disclosure. Because the various channels (for example, PUCCH, PDCCH, or the like) and information element can be identified by any suitable name, the various names assigned to these various channels and information elements shall not be restricted in any way.

In the present disclosure, it is assumed that “base station (BS)”, “radio base station”, “fixed station”, “NodeB”, “eNodeB (eNB)”, “gNodeB (gNB)”, “access point”, “transmission point”, “reception point”, “transmission/reception point”, “cell”, “sector”, “cell group”, “carrier”, “component carrier”, and the like can be used interchangeably. The base station may also be referred to with the terms such as a macro cell, a small cell, a femtocell, or a pico cell.

The base station can accommodate one or more (for example, three) cells (also called sectors). In a configuration in which the base station accommodates a plurality of cells, the entire coverage area of the base station can be divided into a plurality of smaller areas. In each such a smaller area, communication service can be provided by a base station subsystem (for example, a small base station for indoor use (Remote Radio Head: RRH)).

The term “cell” or “sector” refers to a part or all of the coverage area of at least one of a base station and a base station subsystem that perform the communication service in this coverage.

In the present disclosure, the terms “mobile station (MS)”, “user terminal”, “user equipment (UE)”, “terminal” and the like can be used interchangeably.

The mobile station may be called by the persons skilled in the art as a subscriber station, a mobile unit, a subscriber unit, a radio unit, a remote unit, a mobile device, a radio device, a radio communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a radio terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or with some other suitable term.

At least one of a base station and a mobile station may be called a transmitting device, a receiving device, a communication device, or the like. Note that, at least one of a base station and a mobile station may be a device mounted on a moving body, a moving body itself, or the like. The moving body may be a vehicle (for example, a car, an airplane, or the like), a moving body that moves unmanned (for example, a drone, an automatically driven vehicle, or the like), or a robot (manned type or unmanned type). At least one of a base station and a mobile station can be a device that does not necessarily move during the communication operation. For example, at least one of a base station and a mobile station may be an Internet of Things (IoT) device such as a sensor.

Also, a base station in the present disclosure may be read as a mobile station (user terminal, hereinafter the same applies). For example, each of the aspects/embodiments of the present disclosure may be applied to a configuration that allows communication between a base station and a mobile station to be replaced with communication between a plurality of mobile stations (which may be referred to as, for example, Device-to-Device (D2D), Vehicle-to-Everything (V2X), or the like). In this case, the mobile station may have the function of the base station. Words such as “uplink” and “downlink” may also be replaced with wording corresponding to inter-terminal communication (for example, “side”). For example, terms such as an uplink channel, a downlink channel, or the like may be read as a side channel.

Likewise, a mobile station in the present disclosure may be read as a base station. In this case, the base station may have the function of the mobile station.

A radio frame may be configured by one or more frames in the time domain. One frame or each of a plurality frames in the time domain may be called a subframe.

Further, the subframe may be configured by one or more slots in the time domain. The subframe may have a fixed time length (for example, 1 ms) that does not depend on numerology.

The numerology may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. For example, the numerology may indicate at least one of subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), the number of symbols per TTI, a radio frame configuration, specific filtering processing performed by a transceiver in the frequency domain, specific windowing processing performed by the transceiver in the time domain, and the like.