Base station and communication method

Abstract

The present invention is a base station having: a reception unit for receiving capability information including information indicating a first group comprising a band combination that can be used only for particular dual connectivity in a terminal and information indicating a second group comprising a band combination that can be used for the particular dual connectivity; a control unit that, regrading a third group comprising a plurality of band combinations comprising the band combination of the first group and the band combination of the second group, assigns a plurality of indices corresponding to the plurality of band combinations of the third group so that each of the plurality of band combinations of the third group can be identified; and a transmission unit for transmitting, to another base station, a signal that includes the indices and that can be used for communication between base stations.

Description

[Technical field]

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

[0002] For New Radio (also referred to as "NR" or "5G"), the successor system to Long Term Evolution (LTE), 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, and power saving (for example, Non-Patent Document 1).

[0003] In the NR system, a technology called LTE-NR dual connectivity, NR-NR dual connectivity, or multi-RAT (Multi Radio Access Technology) dual connectivity (hereinafter referred to as "MR-DC") has been introduced, which divides data between a base station (eNB) of the LTE system and a base station (gNB) of the NR system, and transmits and receives data simultaneously by these base stations, similar to dual connectivity in the LTE system (for example, Non-Patent Document 2). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V15.4.0(2018-12) [Non-Patent Document 2] 3GPP TS 37.340 V15.4.0(2018-12) [Non-Patent Document 3] 3GPP TS 38.101-3 V15.3.0 (2018-09) [Non-Patent Document 4] 3GPP TSG-RAN WG2 Meeting #105, R2-1900292, Athens, Greece, 25 Feb - 01 Mar 2019 Summary of the Invention [Problem to be solved by the invention]

[0005] NR E-UTRA Dual Connectivity (NE-DC) is a dual connectivity in which the master node is a gNB and the secondary node is an eNB. In NE-DC, a terminal is connected to a gNB operating as a master node and an eNB operating as a secondary node, and the gNB is connected to a 5GC (5G-Core Network).

[0006] There is a need for a method that enables base stations to cooperate with each other to set NE-DC band combinations based on UE capability signaling from a terminal that indicates band combinations that can be used for NE-DC. [Means for solving the problem]

[0007] According to one aspect of the present invention, in a terminal, a receiver receives capability information including information indicating a first group consisting of one or more band combinations usable only for a specific dual connectivity and information indicating a second group consisting of one or more band combinations usable for the specific dual connectivity, and a receiver for receiving capability information including ... third group consisting of a plurality of band combinations consisting of one or more band combinations of the first group and one or more band combinations of the second group, the receiver for receiving capability information including information indicating a first group consisting of one or more band combinations usable only for the specific dual connectivity and information indicating a second group consisting of one or more band combinations usable for the specific dual connectivity. , the position within the third group a control unit that assigns a plurality of indexes corresponding to a plurality of band combinations of the third group so that the base station can identify the band combination; and a transmission unit that transmits a signal that includes the indexes and can be used for communication between base stations to another base station. base station , is provided. Effect of the Invention

[0008] According to an embodiment, a method is provided that enables base stations to configure NE-DC band combinations in cooperation with each other based on UE capability signaling from a terminal indicating band combinations available for NE-DC. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of a network architecture according to an embodiment. [Diagram 2] 1 is a diagram illustrating an example of a configuration of a wireless communication system according to an embodiment. [Diagram 3] FIG. 4 is a sequence diagram for explaining a first operation example in the embodiment. [Figure 4] FIG. 11 is a diagram for explaining examples of information elements used in a first operation example in the embodiment. [Diagram 5] A diagram showing an example of the configuration of a component carrier of an intra-band contiguous EN-DC. [Figure 6] An example of the configuration of a component carrier for intra-band non-contiguous EN-DC is shown. [Figure 7] FIG. 11 is a sequence diagram for explaining a second operation example in the embodiment. [Figure 8] FIG. 11 is a diagram for explaining examples of information elements used in a second operation example in the embodiment. [Figure 9] FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 10] FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 11] FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 12] FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 13] FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 14] FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 15]FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 16] FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 17] FIG. 2 is a diagram illustrating an example of a functional configuration of a base station in an embodiment. [Figure 18] FIG. 2 is a diagram illustrating an example of a functional configuration of a terminal according to an embodiment. [Figure 19] FIG. 2 is a diagram illustrating an example of a hardware configuration of a base station or a terminal in an embodiment. [Figure 20] FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 21] FIG. 13 is a diagram showing an example of a modification of the specifications. [Figure 22] FIG. 13 is a diagram showing an example of a modification of the specifications. 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 embodiments of the present invention described below, terms such as Synchronization signal (SS), Primary SS (PSS), Secondary SS (SSS), Physical broadcast channel (PBCH), and Physical random access channel (PRACH) used in existing LTE are used. This is for convenience of description, and similar signals, functions, and the like may be called by other names. In addition, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, and NR-PRACH. However, even if a signal is used in NR, it is not necessarily indicated 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 embodiments of the present invention, when radio parameters, etc. are "configured," this may mean that a predetermined value is preconfigured, or that radio parameters notified from base station 10 or terminal 20 are set.

[0015] Fig. 1 is a diagram showing a configuration example of a network architecture in an embodiment of the present invention. As shown in Fig. 1, the wireless network architecture in the embodiment of the present invention includes a 4G-CU, a 4G-RU (Remote Unit, a remote radio station), an Evolved Packet Core (EPC), etc. on the LTE-Advanced side. The wireless network architecture in the embodiment of the present invention includes a 5G-CU, a 5G-DU, etc. on the 5G side.

[0016] As shown in Fig. 1, the 4G-CU includes layers such as Radio Resource Control (RRC), Packet Data Convergence Protocol (PDCP), Radio Link Control (RLC), Medium Access Control (MAC), and up to L1 (Layer 1, PHY layer or physical layer), and is connected to the 4G-RU via a Common Public Radio Interface (CPRI). A network node including the 4G-CU and the 4G-RU is called an evolved Node B (eNB).

[0017] On the 5G side, as shown in FIG. 1, the 5G-CU includes an RRC layer, is connected to the 5G-DU via a Fronthaul (FH) interface, and is connected to the 5G Core Network (5GC) via an NG interface. The 5G-CU is also connected to the 4G-CU via an X2 interface. The PDCP layer in the 4G-CU is a coupling or decoupling point when performing 4G-5G Dual Connectivity (DC), i.e., E-UTRA-NR Dual Connectivity (EN-DC). A network node including the 5G-CU and 5G-DU is called a next generation Node B (gNB). The 5G-CU may also be called a gNB-CU, and the 5G-DU may also be called a gNB-DU.

[0018] As shown in Fig. 1, Carrier Aggregation (CA) is performed between 4G-RUs, and DC is performed between 4G-RUs and 5G-DUs. Although not shown, User Equipment (UE) is wirelessly connected via the RF of the 4G-RU or 5G-DU to transmit and receive packets.

[0019] Note that Fig. 1 shows a radio network architecture in LTE-NR DC, i.e., EN-DC (E-UTRA-NR Dual Connectivity). However, a similar radio network architecture may be used when the 4G-CU is separated into CU-DU, or when NR is operated standalone. When the 4G-CU is separated into CU-DU, functions related to the RRC layer and the PDCP layer may be transferred to the 4G-CU, and the RLC layer and below may be included in the 4G-DU. Note that the data rate of the CPRI may be reduced by the CU-DU separation.

[0020] In addition, multiple 5G-DUs may be connected to the 5G-CU. In addition, NR-NR Dual Connectivity (NR-DC) may be performed by connecting a UE to multiple 5G-CUs, or NR-DC may be performed by connecting a UE to multiple 5G-DUs and a single 5G-CU.

[0021] Fig. 2 is a diagram showing an example of the configuration of a wireless communication system according to an embodiment of the present invention, and is a schematic diagram showing a wireless communication system in Multi-RAT Dual Connectivity (MR-DC).

[0022] As shown in FIG. 2, the terminal 20 (which may be a user equipment 20, UE 20) communicates with a base station 10A provided by the LTE system and a base station 10B provided by the NR system (hereinafter, when the base stations 10A and 10B are not distinguished from each other, they may be referred to as "base station 10"). Furthermore, the terminal 20 may support LTE-NR dual connectivity, i.e., EN-DC, in which the base station 10A is a master node (hereinafter, also referred to as "MN") and the base station 10B is a secondary node (hereinafter, also referred to as "SN"). The terminal 20 can simultaneously use multiple component carriers provided by the base station 10A, which is the master node, and the base station 10B, which is the secondary node, to perform simultaneous transmission or simultaneous reception with the base station 10A, which is the master node, and the base station 10B, which is the secondary node.

[0023] It should be noted that the embodiment of the present invention is not limited to the above case. For example, in FIG. 2, the base station 10A may be a base station provided by the NR system, and the base station 10B may be a base station provided by the LTE system. In this case, the terminal 20 may support NR-LTE dual connectivity, i.e., NE-DC, in which the base station 10A is an MN and the base station 10B is an SN. The terminal 20 can simultaneously use multiple component carriers provided by the base station 10A, which is a master node, and the base station 10B, which is a secondary node, to perform simultaneous transmission or simultaneous reception with the base station 10A, which is a master node, and the base station 10B, which is a secondary node. Also, for example, in FIG. 2, the base station 10A may be a base station provided by the NR system, and the base station 10B may be a base station provided by the NR system. In this case, the terminal 20 may support NR-NR dual connectivity, i.e., NR-DC, in which the base station 10A is an MN and the base station 10B is an SN.

[0024] Note that the following examples are mainly described with respect to LTE-NR dual connectivity, but the base station 10 and terminal 20 according to the embodiments of the present invention are not limited to LTE-NR dual connectivity, and are applicable to dual connectivity between multiple wireless communication systems using different RATs, i.e., MR-DC.

[0025] When EN-DC is configured by configuring LTE component carriers and NR component carriers in the same frequency band, the LTE component carriers and the NR component carriers are included in the same frequency band. For example, it is assumed that the LTE component carriers are configured in the lower frequency band portion of the frequency band, and the NR component carriers are configured in the higher frequency band portion of the frequency band. In another case, it is assumed that the LTE component carriers are configured in the higher frequency band portion of the frequency band, and the NR component carriers are configured in the lower frequency band portion of the frequency band.

[0026] In such a case, in order to prevent the portion of the frequency band in which the LTE component carrier is set from overlapping with the portion of the frequency band in which the NR component carrier is set, it is necessary to communicate some information between the eNB and the gNB.

[0027] A method has been proposed in which multiple scenarios (patterns of component carrier placement) assumed in the cases of intra-band contiguous EN-DC and intra-band non-contiguous EN-DC are enumerated, and all information indicating the center frequency and bandwidth of each of the multiple component carriers used in each scenario is transmitted.

[0028] According to this method, it is possible to prevent the frequency band portion in which the LTE component carrier is set from overlapping with the frequency band portion in which the NR component carrier is set. However, this method may increase the amount of information to be transmitted from the eNB to the gNB.

[0029] In this way, when configuring an EN-DC (which may be a NE-DC or an NR-DC) by configuring an LTE component carrier and an NR component carrier in the same frequency band (intra-band EN-DC (which may be an intra-band NE-DC or an intra-band NR-DC)), in order to prevent overlap between the part of the frequency band in which the LTE (or NR) component carrier is configured and the part of the frequency band in which the NR (or LTE) component carrier is configured, it is necessary to reduce the amount of information when base station 10A in FIG. 2 notifies base station 10B in FIG. 2 of information.

[0030] (Method 1) Hereinafter, an example of method 1 will be described for reducing the amount of information transmitted from the base station 10A to the base station 10B so that the frequency band portion in which the LTE component carrier is set does not overlap with the frequency band portion in which the NR component carrier is set in the intra-band EN-DC. Note that the case in which method 1 is applied is not limited to intra-band EN-DC. By making appropriate changes as necessary, method 1 can be applied to intra-band NE-DC and intra-band NR-DC.

[0031] First, for the sake of simplicity, an example will be considered in which only one component carrier is set in a single frequency band on the base station 10A side. In this case, the base station 10A, which is a Master Node, notifies the base station 10B of information indicating the lower end position and the upper end position on the frequency axis of one component carrier to be set. The base station 10B, which has received the information indicating the lower end position and the upper end position on the frequency axis of one component carrier set by the base station 10A, can use the received information to set one or more component carriers in a frequency band other than the frequency band specified by the lower end position and the upper end position on the frequency axis in the above-mentioned single frequency band. When multiple component carriers are set in a single frequency band on the base station 10A side, it is sufficient to notify the base station 10B of information indicating the lower end position and the upper end position on the frequency axis of each component carrier set by the base station 10A. The base station 10B, which has received information indicating the upper and lower end positions on the frequency axis of each component carrier set by the base station 10A, can use the received information to set one or more component carriers in a frequency band other than the frequency bands corresponding to the upper and lower end positions on the frequency axis of each component carrier in the above-mentioned single frequency band.

[0032] (Example of Method 1) Next, an operation example of method 1 will be described with reference to FIG. 3. First, in step S101, the base station 10A determines one or more frequency bands in which one or more LTE component carriers are set in a single frequency band. Next, the base station 10A creates information indicating the lower end position and the upper end position on the frequency axis of each frequency band among one or more frequency bands in which one or more LTE component carriers are set. Then, in step S102, the base station 10A transmits the created information indicating the lower end position and the upper end position on the frequency axis of each frequency band to the base station 10B. The base station 10B, which has received the information indicating the lower end position and the upper end position on the frequency axis of each component carrier set by the base station 10A, can use the received information to set one or more NR component carriers in a frequency band other than each frequency band corresponding to the lower end position and the upper end position on the frequency axis of each component carrier in the above-mentioned single frequency band. In addition, when the base station 10B receives the information indicating the lower end position and the upper end position on the frequency axis of each component carrier set by the base station 10A, if there is some reason, such as the frequency position of each component carrier set by the base station 10A causing interference with other communications by the base station 10B, that makes it necessary to reconfigure the frequency position of any of the component carriers set by the base station 10A, the base station 10B may transmit information to the base station 10A requesting reconfiguration of the frequency position of the component carrier.

[0033] According to method 1, it is possible to reduce the amount of information to be transmitted, compared to a method of notifying information indicating the center frequency and bandwidth of each component carrier among multiple component carriers used in each scenario for all scenarios of component carrier placement.

[0034] FIG. 4 is a diagram showing an example of an information element used in an operation example of the method 1. FIG. 4 is an example of an inter-node RRC message "CG-ConfigInfo". "CG-ConfigInfo" is transmitted from the LTE-RAN master node to the NG-RAN secondary node. Alternatively, "CG-ConfigInfo" may be transmitted from the NG-RAN master node to the LTE-RAN secondary node. "CG-ConfigInfo" is an information element for performing connection establishment, change, release, etc. in the secondary group.

[0035] As shown in FIG. 4, "CG-ConfigInfo" includes an information element "CG-ConfigInfo-IEs". "CG-ConfigInfo-IEs" includes "configuredFrequencyRangeMCG". "configuredFrequencyRangeMCG" specifies whether the master node is an LTE node or an NR node. If the master node is an LTE node, "FrequencyRangeEUTRA" specifies the lower end position and the upper end position on the frequency axis of each of one or more frequency bands in which one or more LTE component carriers are configured. If the master node is an NR node, "FrequencyRangeNR" specifies the lower end position and the upper end position on the frequency axis of each of one or more frequency bands in which one or more NR component carriers are configured.

[0036] (Method 2) Hereinafter, an example of method 2 will be described in which the amount of information transmitted from the base station 10A to the base station 10B is reduced so that the frequency band portion in which the LTE component carrier is set does not overlap with the frequency band portion in which the NR component carrier is set in the intra-band EN-DC. Note that the case in which method 2 is applied is not limited to intra-band EN-DC. By making appropriate changes as necessary, method 2 can be applied to intra-band NE-DC and intra-band NR-DC.

[0037] In method 2, a table showing the configuration of component carriers of an intra-band contiguous EN-DC (FIG. 5) or a table showing the configuration of component carriers of an intra-band non-contiguous EN-DC (FIG. 6) is used.

[0038] FIG. 5 is a diagram showing an example of a table showing the EN-DC configuration (the configuration of the LTE component carrier and the NR component carrier) and the bandwidth combination set of the intra-band contiguous EN-DC.

[0039] According to the table in FIG. 5, an E-UTRA-NR configuration / Bandwidth combination set is specified for each EN-DC configuration (e.g., DC_(n)41AA) used for the Downlink EN-DC configuration and the Uplink EN-DC configuration. For example, in the case of DC_(n)41AA, the E-UTRA Band used is 41, and the NR Band used is n41. In this case, the uplink frequency band is 2496MHz to 2690MHz, and the downlink frequency band is 2496MHz to 2690MHz (TDD is applied). The maximum value of the aggregated bandwidth is 120MHz.

[0040] Two types of Bandwidth combination sets (0 and 1) are specified. When Bandwidth combination set is 0, the bandwidth of the LTE component carrier is 20 MHz, and the bandwidth of the NR component carrier is one of 40 MHz, 60 MHz, 80 MHz, and 100 MHz. When Bandwidth combination set is 1, the bandwidth of the LTE component carrier is 20 MHz, and the bandwidth of the NR component carrier is one of 40 MHz, 50 MHz, 60 MHz, 80 MHz, and 100 MHz.

[0041] For example, when the Bandwidth combination set is 0, as an example in which the LTE component carrier is placed in the lower frequency portion and the NR component carrier is placed in the higher frequency portion, the table shows that any of the following combinations of the bandwidths of the LTE component carrier and the NR component carrier can be used. These combinations include {20 MHz, 40 MHz}, {20 MHz, 60 MHz}, {20 MHz, 80 MHz}, and {20 MHz, 100 MHz}.

[0042] Also, for example, when the Bandwidth combination set is 0, as an example where the NR component carrier is arranged in the lower frequency portion and the LTE component carrier is arranged in the higher frequency portion, the table shows that any of the combinations of {40 MHz, 20 MHz}, {60 MHz, 20 MHz}, {80 MHz, 20 MHz}, and {100 MHz, 20 MHz} can be used.

[0043] Therefore, by using the table of Fig. 5, the base station 10A notifies the base station 10B of an index specifying the EN-DC configuration and the bandwidth combination, so that the base station 10B can set the frequency position of the NR component carrier so as not to overlap with the part of the frequency band in which the base station 10A sets the LTE component carrier. In this case, a parameter indicating whether the LTE component carrier is assigned to the lower part of the aggregated frequency band or the LTE component carrier is assigned to the higher part of the aggregated frequency band in the aggregated frequency band in which the LTE component carrier and the NR component carrier are set may be additionally transmitted. As such a parameter, for example, componentCarrierPositionEUTRA may be defined and set to take one of the values ​​{lower, upper}.

[0044] Additionally or alternatively, in order to explicitly specify the position of the LTE component carrier, for example, in addition to the index specifying the EN-DC configuration and the band combination, the base station 10A may transmit to the base station 10B information indicating the center frequency of the frequency band in which the LTE component carrier is set, information indicating the lower end frequency position of the frequency band in which the LTE component carrier is set, and / or information indicating the upper end frequency position of the frequency band in which the LTE component carrier is set.

[0045] In this case, for example, a new index may be defined for the above-mentioned index and the information indicating the center frequency of the frequency band in which the LTE component carrier is set, and the base station 10A may notify the base station 10B of the defined new index. Alternatively or additionally, a new index may be defined for the above-mentioned index and the information indicating the lower end frequency position of the frequency band in which the LTE component carrier is set, and the base station 10A may notify the base station 10B of the defined new index. Alternatively or additionally, a new index may be defined for the above-mentioned index and the information indicating the upper end frequency position of the frequency band in which the LTE component carrier is set, and the base station 10A may notify the base station 10B of the defined new index.

[0046] FIG. 6 is a diagram illustrating an example of a table showing a configuration of component carriers of an intra-band non-contiguous EN-DC.

[0047] According to the table in FIG. 6, an E-UTRA-NR configuration / Bandwidth combination set is specified for each EN-DC configuration (e.g., DC_41A_n41A) used for the Downlink EN-DC configuration and the Uplink EN-DC configuration. For example, when the EN-DC configuration used is DC_41A_n41A, the E-UTRA Band used is 41, and the NR Band used is n41. In this case, the uplink frequency band is 2496MHz to 2690MHz, and the downlink frequency band is 2496MHz to 2690MHz (TDD is applied). The maximum value of the aggregated bandwidth is 120MHz.

[0048] Two types of Bandwidth combination sets (0 and 1) are specified. When Bandwidth combination set is 0, the bandwidth of the LTE component carrier is 20 MHz, and the bandwidth of the NR component carrier is one of 40 MHz, 60 MHz, 80 MHz, and 100 MHz. When Bandwidth combination set is 1, the bandwidth of the LTE component carrier is 20 MHz, and the bandwidth of the NR component carrier is one of 40 MHz, 50 MHz, 60 MHz, 80 MHz, and 100 MHz.

[0049] For example, when the Bandwidth combination set is 0, as an example in which the LTE component carrier is placed in the lower frequency portion and the NR component carrier is placed in the higher frequency portion, the table shows that any of the following combinations of the bandwidths of the LTE component carrier and the NR component carrier can be used. These combinations include {20 MHz, 40 MHz}, {20 MHz, 60 MHz}, {20 MHz, 80 MHz}, and {20 MHz, 100 MHz}.

[0050] Also, for example, when the Bandwidth combination set is 0, as an example where the NR component carrier is arranged in the lower frequency portion and the LTE component carrier is arranged in the higher frequency portion, the table shows that any of the combinations of {40 MHz, 20 MHz}, {60 MHz, 20 MHz}, {80 MHz, 20 MHz}, and {100 MHz, 20 MHz} can be used.

[0051] Therefore, by using the table of Fig. 6, the base station 10A notifies the base station 10B of an index specifying the EN-DC configuration and the bandwidth combination, so that the base station 10B can set the frequency position of the NR component carrier so as not to overlap with the part of the frequency band in which the base station 10A sets the LTE component carrier. In this case, a parameter indicating whether the LTE component carrier is assigned to the lower part of the aggregated frequency band in which the LTE component carrier and the NR component carrier are set, or the LTE component carrier is assigned to the higher part of the aggregated frequency band, may be additionally transmitted. As such a parameter, for example, componentCarrierPositionEUTRA may be defined and set to take one of the values ​​{lower, upper}.

[0052] Additionally or alternatively, in order to explicitly specify the position of the LTE component carrier, for example, the base station 10A may transmit to the base station 10B, in addition to an index specifying the EN-DC configuration and band combination, information indicating a center frequency of a frequency band in which the LTE component carrier is set, information indicating a lower end frequency position of a frequency band in which the LTE component carrier is set, and / or information indicating an upper end frequency position of a frequency band in which the LTE component carrier is set.

[0053] In this case, for example, a new index may be defined for the above-mentioned index and the information indicating the center frequency of the frequency band in which the LTE component carrier is set, and the base station 10A may notify the base station 10B of the defined new index. Alternatively or additionally, a new index may be defined for the above-mentioned index and the information indicating the lower end frequency position of the frequency band in which the LTE component carrier is set, and the base station 10A may notify the base station 10B of the defined new index. Alternatively or additionally, a new index may be defined for the above-mentioned index and the information indicating the upper end frequency position of the frequency band in which the LTE component carrier is set, and the base station 10A may notify the base station 10B of the defined new index.

[0054] According to method 2, it is possible to reduce the amount of information to be transmitted, compared to a method of notifying information indicating the center frequency and bandwidth of each component carrier among multiple component carriers used in each scenario for all scenarios of component carrier placement.

[0055] (Example of Method 2) Next, an operation example of the method 2 will be described with reference to FIG. 7. First, in step S201, the base station 10A determines one or more frequency bands in which one or more LTE component carriers are set in a single frequency band. Next, the base station 10A refers to a table that specifies an E-UTRA-NR configuration / Bandwidth combination set for each EN-DC configuration used in the Downlink EN-DC configuration and the Uplink EN-DC configuration, and identifies an index indicating an E-UTRA-NR configuration / Bandwidth combination set corresponding to one or more frequency bands of the set one or more LTE component carriers. In step S202, the base station 10A transmits a signal indicating the identified index to the base station 10B. The base station 10B that receives the index indicating the E-UTRA-NR configuration / Bandwidth combination set corresponding to one or more frequency bands of the set one or more LTE component carriers set by the base station 10A can use the received index to set the frequency bands in which each component carrier is set based on the E-UTRA-NR configuration / Bandwidth combination set in the above-mentioned single frequency band. In addition, when there is some reason, such as when the frequency position of each component carrier set by the base station 10A causes interference with other communications by the base station 10B, and it is necessary to reconfigure the frequency position of any of the component carriers set by the base station 10A, the base station 10B may transmit, to the base station 10A, information requesting reconfiguration of the frequency position of the component carrier.

[0056] FIG. 8 is a diagram showing an example of an information element used in an operation example of the method 2. FIG. 8 is an example of an inter-node RRC message "CG-ConfigInfo". "CG-ConfigInfo" is transmitted from the LTE-RAN master node to the NG-RAN secondary node. Alternatively, "CG-ConfigInfo" may be transmitted from the NG-RAN master node to the LTE-RAN secondary node. "CG-ConfigInfo" is an information element for performing connection establishment, change, release, etc. in the secondary group.

[0057] As shown in FIG. 8, "CG-ConfigInfo" includes an information element "CG-ConfigInfo-IEs". "CG-ConfigInfo-IEs" includes "allowedBandwidthCombinationSet". "allowedBandwidthCombinationSet" is information indicating an E-UTRA-NR configuration / Bandwidth combination set. For example, "allowedBandwidthCombinationSet" may be an index. Furthermore, "componentCarrierPositionEUTRA" included in "CG-ConfigInfo-IEs" is set to lower or upper. When "componentCarrierPositionEUTRA" is set to lower, this corresponds to a case where an LTE component carrier is allocated to a lower frequency portion of an aggregated frequency band. When "componentCarrierPositionEUTRA" is set to upper, this corresponds to a case where an LTE component carrier is allocated to a higher frequency portion of an aggregated frequency band.

[0058] In the above examples, examples of signaling that can be used in the case of EN-DC have been mainly described. Below, an example of signaling between nodes in the case of NE-DC will be described.

[0059] Dual connectivity using E-UTRA and NR radio access technologies is called Multi-RAT-Dual Connectivity (MR-DC). In MR-DC, one of the E-UTRA node and the NR node operates as a master node, and the other operates as a secondary node. NR E-UTRA Dual Connectivity (NE-DC) is a dual connectivity in which the master node (e.g., base station 10A in FIG. 2) is a gNB, and the secondary node (e.g., base station 10B in FIG. 2) is an eNB. In NE-DC, the terminal 20 is connected to a gNB operating as a master node and an eNB operating as a secondary node, and the gNB is connected to a 5GC (5G-Core Network).

[0060] (Proposal 1) In the following, when the terminal 20 supports a band combination usable only for the NE-DC, an example of signaling for setting the NE-DC band combination between base stations based on UE capability signaling indicating the band combination usable only for the NE-DC from the terminal 20 will be described. It is possible to use a supportedBandCombinationList field as an inter-node message of the MR-DC.

[0061] If the terminal 20 supports a band combination that can only be used for NE-DC, for example, the terminal 20 notifies the band combination to the gNB, which is the master node, by a dedicated capability signaling called supportedBandCombinationListNEDC-Only.

[0062] However, it is not assumed that the supportedBandCombinationListNEDC-only field is used as an inter-node message of MR-DC. In other words, it is not assumed that the master node notified of the band combinations available only for NE-DC by the terminal 20 in the supportedBandCombinationListNEDC-only field restricts the band combinations for the secondary cell group (SCG) according to one or more band combinations notified in the supportedBandCombinationListNEDC-only field.

[0063] As a method for solving the above problem, for example, by adding a new field to the CG-ConfigInfo IE, it is possible to adjust functions between MR-DC nodes based on one or more band combinations notified by the terminal 20 in the supportedBandCombinationListNEDC-only field. When setting the NE-DC band combination between MR-DC nodes based on the CG-ConfigInfo, for example, a request for a band combination other than one or more band combinations in the supportedBandCombinationListNEDC-Only and permitted by the master node may be permitted to be made to the secondary node. Furthermore, a band combination selected from one or more band combinations in the supportedBandCombinationListNEDC-Only and permitted by the master node may be permitted to be notified to the master node by the secondary node.

[0064] 9 and 10 are diagrams showing examples of specification changes. Figures 9 and 10 show an example of changing a CG-Config message. The CG-Config message may be a message transmitted from a secondary node to a master node.

[0065] For example, as shown in the example of FIG. 9, fields called selectedBandCombinationNEDC and requestedBC-NEDC for notifying about NE-DC may be added to the CG-Config message.

[0066] FIG. 10 shows an example of the changed portion of the CG-Config field descriptions when the CG-Config message is changed as shown in the example of FIG.

[0067] As shown in the example of Figure 10, the requestedBC-MRDC field may be used to request the configuration of any band combination in the supportedBandCombinationList in the UE-MRDC-Capability (in the case of EN-DC or NE-DC) or in the UE-NR-Capability (in the case of NR-DC), and may be used to request the corresponding feature sets that are prohibited from being used in the master node (i.e., other than allowedBC-ListMRDC) to allow renegotiation of the UE capability for the configuration of the SCG. In the case of NE-DC and when this field is included in the CG-Config message, the requestedBC-NEDC field may not be included.

[0068] Also, as shown in the example of Figure 10, the requestedBC-NE-DC field may be used to request the configuration of any band combination in supportedBandCombinationListNEDC-Only, and may be used to request the corresponding feature sets that are prohibited from being used in the master node (i.e., other than allowedBC-ListNEDC) to allow renegotiation of UE capabilities for SCG configuration. If this field is included in the CG-Config message, the requestedBC-MRDC field may not be included. This field may be used only in the case of NE-DC.

[0069] Also, as shown in the example of FIG. 10, the selectedBandCombination field may indicate a band combination selected by the secondary node among one or more band combinations permitted by the allowedBC-ListMRDC in the case of EN-DC, NE-DC, and NR-DC. When the band combination and / or feature set selected by the secondary node for the SCG is changed (i.e., even if the new selection of the band combination and / or feature set is permitted by the allowedBC-ListMRDC), the secondary node may notify the master node of this field. In the case of NE-DC, and when this field is included in the CG-Config message, the selectedBandCombinationNEDC may not be included.

[0070] Also, as shown in the example of FIG. 10, the selectedBandCombinationNEDC field may indicate a band combination selected by the secondary node from one or more band combinations permitted by allowedBC-ListNEDC in the case of NE-DC. When the band combination and / or feature set selected by the secondary node for the SCG is changed (i.e., even if the new selection of the band combination and / or feature set is permitted by allowedBC-ListNEDC), the secondary node may notify the master node of this field. When this field is included in the CG-Config message, selectedBandCombination may not be included. This field may be used only in the case of NE-DC.

[0071] Figures 11 and 12 are diagrams showing examples of specification changes. Figures 11 and 12 show an example of changing a CG-ConfigInfo message. The CG-ConfigInfo message may be a message transmitted from a master node to a secondary node.

[0072] For example, as shown in the example of FIG. 11, a field called allowedBC-ListNEDC for notifying about NE-DC may be added to the CG-ConfigInfo message.

[0073] FIG. 12 shows an example of a changed portion of the CG-ConfigInfo field descriptions when the CG-ConfigInfo message is changed as shown in the example of FIG.

[0074] As shown in the example of FIG. 12, the allowedBC-ListNEDC field may indicate a list of indices specifying one or more band combinations in the NE-DC capabilities from which the secondary node is allowed to select an SCG band combination. Each element in the allowedBC-ListNEDC field may indicate one band combination among the band combinations numbered according to the supportedBandCombinationListNEDC-Only. All MR-DC band combinations indicated by this field may be a superset of one or more MCG bands selected by the master node. If allowedBC-ListMRDC is included in the CG-ConfigInfo message and this field is not included, the secondary node is not allowed to select an SCG band combination from the supportedBandCombinationListNEDC-Only. If allowedBC-ListMRDC is not included in the CG-ConfigInfo message and this field is included, the secondary node is not allowed to select an SCG band combination from the supportedBandCombinationList. This field may be used only in the case of NE-DC.

[0075] (Example of operation) For example, it is assumed that the terminal 20 supports one or more band combinations usable only for the NE-DC. The terminal 20 notifies the master node of one or more band combinations usable only for the NE-DC using supportedBandCombinationListNEDC-Only indicating one or more band combinations usable only for the NE-DC. The master node that receives information indicating one or more band combinations usable only for the NE-DC from the terminal 20 may, for example, include information indicating one or more band combinations usable only for the NE-DC in allowedBC-ListNEDC included in the CG-ConfigInfo message and transmit the CG-ConfigInfo message to the secondary node. The secondary node may select one of the band combinations usable only for the NE-DC notified by the master node, include information indicating the selected band combination in selectedBandCombinationNEDC, and notify the master node of the CG-Config message including the selectedBandCombinationNEDC. According to this method, when performing NE-DC, the master node and the secondary node can set a band combination that can be used only for NE-DC indicated in supportedBandCombinationListNEDC-Only notified from the terminal 20.

[0076] (Proposal 2) In the following, when terminal 20 supports a band combination usable only for NE-DC, another example of signaling for setting an NE-DC band combination between base stations based on UE capability signaling indicating a band combination usable only for NE-DC from terminal 20 will be described. In the following example, existing signaling is applied to NE-DC only band combination, and an indicator is added in CG-ConfigInfo and CG-Config, and the indicator indicates whether CG-ConfigInfo and CG-Config are for NE-DC only, thereby enabling the existing signaling to be used in the case of NE-DC.

[0077] If the terminal 20 supports a band combination that can only be used for NE-DC, for example, the terminal 20 notifies the band combination to the gNB, which is the master node, by a dedicated capability signaling called supportedBandCombinationListNEDC-Only.

[0078] However, it is not assumed that the supportedBandCombinationListNEDC-only field is used as an inter-node message of MR-DC. In other words, it is not assumed that the master node notified of the band combinations available only for NE-DC by the terminal 20 in the supportedBandCombinationListNEDC-only field restricts the band combinations for the secondary cell group (SCG) according to one or more band combinations notified in the supportedBandCombinationListNEDC-only field.

[0079] As a method for solving the above problem, for example, by adding a new field to the CG-ConfigInfo IE, it is possible to adjust the functions between the MR-DC nodes based on one or more band combinations notified by the terminal 20 in the supportedBandCombinationListNEDC-only field. When setting the NE-DC band combination between the MR-DC nodes based on the CG-Config, for example, it may be permitted to request a band combination other than one or more band combinations in the supportedBandCombinationListNEDC-Only and permitted by the master node from the secondary node. Furthermore, it may be permitted to notify the master node of a band combination selected from one or more band combinations in the supportedBandCombinationListNEDC-Only and permitted by the master node.

[0080] 13 and 14 are diagrams showing examples of specification changes. Figures 13 and 14 show an example of changing a CG-Config message. The CG-Config message may be a message sent from a secondary node to a master node.

[0081] For example, as shown in the example of FIG. 13, a field called useBandCombinationListNEDC-Only for notifying about NE-DC may be added to the CG-Config message.

[0082] FIG. 14 shows an example of the changed portion of the CG-Config field descriptions when the CG-Config message is changed as shown in the example of FIG. 13.

[0083] As shown in the example of FIG. 14, when the value of the useBandCombinationListNEDC-Only field is set to true, the requestedBC-MRDC field may be used to request the configuration of band combinations in the supportedBandCombinationListNEDC-Only and to request corresponding feature sets that are prohibited from being used by the master node (i.e., other than allowedBC-ListMRDC) to allow renegotiation of UE capabilities for the configuration of SCG, and the selectedBandCombination field may indicate a band combination selected by the secondary node among one or more band combinations allowed by allowedBC-ListMRDC. When the band combination and / or feature set selected by the secondary node for the SCG is changed (i.e., even if the new selection of the band combination and / or feature set is allowed by allowedBC-ListMRDC), the secondary node may notify the master node of this field. This field may be used only in the case of NE-DC.

[0084] (Modification of FIG. 14) Note that the band combination for NE-DC is included not only in the supportedBandCombinationListNEDC-only field but also in the supportedBandCombinationList. Therefore, in order to enable a unique designation of a band combination for NE-DC, for example, one or more band combinations included in the supportedBandCombinationList are arranged in ascending order of the original indexes of the one or more band combinations in the supportedBandCombinationList, and then one or more band combinations included in the supportedBandCombinationListNEDC-Only are arranged in ascending order of the original indexes of the one or more band combinations in the supportedBandCombinationListNEDC-Only, and then indexes are again assigned to the arranged multiple band combinations in ascending order. Note that, in the embodiment, the band combinations are arranged in ascending order of the indexes, but the arrangement of the band combinations is not limited to ascending order. For example, the band combinations may be arranged in descending order of the indexes.

[0085] For example, assume that the indexes assigned to the band combinations for NE-DC included in the supportedBandCombinationList are #1, #2, and #3, and the indexes assigned to the band combinations included in the supportedBandCombinationListNEDC-Only are #2, #3, and #4. In this case, the band combinations #1, #2, and #3 included in the supportedBandCombinationList are arranged, and then the band combinations #2, #3, and #4 included in the supportedBandCombinationListNEDC-Only are arranged, and new indexes 1, 2, and 3 are assigned to the band combinations #1, #2, and #3 included in the supportedBandCombinationList, respectively, and new indexes 4, 5, and 6 are assigned to the band combinations #2, #3, and #4 included in the supportedBandCombinationListNEDC-Only, respectively, thereby making it possible to uniquely specify the band combinations for NE-DC.

[0086] FIG. 20 is a diagram showing a modified example of the specification. FIG. 20 shows a modified portion of the BandCombinationInfoSN field. As shown in FIG. 20, the bandCombinationIndex field indicates the position of the band combination in the supportedBandCombinationList. For example, when useBandCombinationListNEDC-Only is set to true, the bandCombinationIndex field may indicate one of a plurality of indexes newly assigned in ascending order to the arranged band combinations, after arranging one or more band combinations for NE-DC included in the supportedBandCombinationList in ascending order of the original indexes of the one or more band combinations in the supportedBandCombinationList, and then arranging one or more band combinations included in the supportedBandCombinationListNEDC-Only in ascending order of the original indexes of the one or more band combinations in the supportedBandCombinationListNEDC-Only.

[0087] Note that this embodiment is not limited to this example. For example, when useBandCombinationListNEDC-Only is set to true, the bandCombinationIndex field may indicate one of a plurality of indexes newly assigned to the arranged band combinations in ascending order after arranging one or more band combinations included in supportedBandCombinationListNEDC-Only in ascending order of the original indexes of the one or more band combinations in supportedBandCombinationListNEDC-Only, and then arranging one or more band combinations for NE-DC included in supportedBandCombinationList in ascending order of the original indexes of the one or more band combinations in supportedBandCombinationList.

[0088] Figures 15 and 16 are diagrams showing examples of specification changes. Figures 15 and 16 show an example of changing a CG-ConfigInfo message. The CG-ConfigInfo message may be a message transmitted from a master node to a secondary node.

[0089] For example, as shown in the example of FIG. 15, a field called useBandCombinationListNEDC-Only for notifying about the NE-DC may be added to the CG-ConfigInfo message.

[0090] FIG. 16 shows an example of a changed portion of the CG-ConfigInfo field descriptions when the CG-ConfigInfo message is changed as shown in the example of FIG. 15.

[0091] As shown in the example of FIG. 16, when the value of the useBandCombinationListNEDC-Only field is set to true, the allowedBC-ListMRDC field may indicate one or more band combinations in the NE-DC capabilities from which the secondary node is allowed to select an SCG band combination. Each element in the allowedBC-ListMRDC field may indicate one band combination among the band combinations numbered according to the supportedBandCombinationListNEDC-Only. All MR-DC band combinations indicated by this field may be a superset of one or more MCG bands selected by the master node. If the allowedBC-ListMRDC is included in the CG-ConfigInfo message and this field is not included, the secondary node is not allowed to select an SCG band combination from the supportedBandCombinationListNEDC-Only. If allowedBC-ListMRDC is not included in the CG-ConfigInfo message and this field is included, the secondary node is not allowed to select an SCG band combination from the supportedBandCombinationList. This field may only be used in the case of NE-DC.

[0092] (Example of operation) For example, it is assumed that the terminal 20 supports one or more band combinations usable only for the NE-DC. The terminal 20 notifies the master node of one or more band combinations usable only for the NE-DC by using supportedBandCombinationListNEDC-Only indicating one or more band combinations usable only for the NE-DC. The master node that receives information indicating one or more band combinations usable only for the NE-DC from the terminal 20 may set the value of the useBandCombinationListNEDC-Only field included in the CG-ConfigInfo message to true, and transmit the CG-ConfigInfo message to the secondary node. The secondary node may receive a CG-ConfigInfo message notified from the master node, detect that the value of the useBandCombinationListNEDC-Only field is set to true, select one of the band combinations from one or more band combinations that can be used only for the NE-DC in the allowedBC-ListMRDC, include information indicating the selected band combination in selectedBandCombination, include the selectedBandCombination in a CG-Config message, set the value of the useBandCombinationListNEDC-Only field in the CG-Config message to true, and notify the master node of the CG-Config message. According to this method, when performing NE-DC, the master node and the secondary node can set a band combination that can be used only for the NE-DC indicated in the supportedBandCombinationListNEDC-Only notified from the terminal 20.

[0093] (Modification of FIG. 16) Note that the band combination for NE-DC is included not only in the supportedBandCombinationListNEDC-only field but also in the supportedBandCombinationList. Therefore, the useBandCombinationListNEDC-Only field may be changed as shown in the example of FIG. 21. That is, as shown in the example of FIG. 21, when the value of the useBandCombinationListNEDC-Only field is set to true, the allowedBC-ListMRDC field may indicate one or more band combinations in the NE-DC capabilities from which the secondary node is allowed to select the SCG band combination. Each element in the allowedBC-ListMRDC field may indicate one of the band combinations numbered according to the supportedBandCombinationList and the supportedBandCombinationListNEDC-Only. All MR-DC band combinations indicated by this field may be a superset of one or more MCG bands selected by the master node.

[0094] Note that the band combination for NE-DC is included not only in the supportedBandCombinationListNEDC-only field but also in the supportedBandCombinationList. Therefore, in order to make it possible to uniquely specify the band combination for NE-DC, for example, one or more band combinations included in the supportedBandCombinationList are arranged in ascending order of the original indexes of the one or more band combinations in the supportedBandCombinationList, and then one or more band combinations included in the supportedBandCombinationListNEDC-Only are arranged in ascending order of the original indexes of the one or more band combinations in the supportedBandCombinationListNEDC-Only, and then indexes are again assigned to the arranged band combinations in ascending order.

[0095] FIG. 22 is a diagram showing a modified example of the specification. FIG. 22 shows a modified portion of the BandCombinationInfo field. As shown in FIG. 22, the bandCombinationIndex field indicates the position of the band combination in the supportedBandCombinationList. For example, when useBandCombinationListNEDC-Only is set to true, the bandCombinationIndex field may indicate one of a plurality of indexes newly assigned in ascending order to the arranged band combinations, after arranging one or more band combinations for NE-DC included in the supportedBandCombinationList in ascending order of the original indexes of the one or more band combinations in the supportedBandCombinationList, and then arranging one or more band combinations included in the supportedBandCombinationListNEDC-Only in ascending order of the original indexes of the one or more band combinations in the supportedBandCombinationListNEDC-Only.

[0096] (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.

[0097] <Base station 10> Fig. 17 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. 17, 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. 17 is merely an example. The functional divisions and names of the functional units may be any as long as they can execute the operations related to the embodiment of the present invention.

[0098] 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.

[0099] The setting unit 130 stores in a storage device preset setting information and various setting information to be transmitted to the terminal 20, and reads out from the storage device as necessary. The content of the setting information is setting information related to communication of the terminal 20, such as setting of a radio bearer or setting of a secondary cell, for example.

[0100] As described in the embodiment, the control unit 140 generates information indicating the lower end position and the upper end position on the frequency axis of each of one or more component carriers set in a single frequency band. The transmission unit 110 transmits the information indicating the lower end position and the upper end position on the frequency axis of each component carrier generated by the control unit 140 to another network node. In addition, the reception unit 120 may receive a signal requesting reconfiguration of the frequency band of any of the set component carriers from the other network node.

[0101] Furthermore, the control unit 140 determines one or more frequency bands in which one or more LTE component carriers are set in a single frequency band. The control unit 140 refers to a table indicating indexes of the Downlink EN-DC configuration and the Uplink EN-DC configuration stored in the setting unit 130, and identifies an index indicating an E-UTRA-NR configuration / Bandwidth combination set corresponding to one or more frequency bands of the set one or more LTE component carriers. The transmission unit 110 transmits the index identified by the control unit 140 to another network node. Furthermore, the reception unit 120 may receive a signal requesting reconfiguration of the frequency band of any of the set component carriers from another network node. Furthermore, the reception unit 120 receives from the terminal 20 a supportedBandCombinationListNEDC-Only indicating one or more band combinations usable only for the NE-DC, and detects information indicating one or more band combinations usable only for the NE-DC. The control unit 140 may, for example, include information indicating one or more band combinations that can only be used for the NE-DC in the allowedBC-ListNEDC included in the CG-ConfigInfo message, and the transmission unit 110 may transmit the CG-ConfigInfo message to the secondary node.

[0102] <Terminal 20> Fig. 18 is a diagram showing an example of a functional configuration of terminal 20 in the embodiment of the present invention. As shown in Fig. 10, terminal 20 has transmitting unit 210, receiving unit 220, setting unit 230, and control unit 240. The functional configuration shown in Fig. 18 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.

[0103] 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, etc. 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), etc. to another terminal 20 as D2D communication, and the receiver 120 receives the PSCCH, the PSSCH, the PSDCH, or the PSBCH, etc. from the other terminal 20.

[0104] The setting unit 230 stores various setting information received from the base station 10 or the terminal 20 by the receiving unit 220 in a storage device, and reads it out from the storage device as necessary. The setting unit 230 also stores setting information that is set in advance. The content of the setting information is, for example, setting information related to communication of the terminal 20, such as setting of a radio bearer or a secondary cell, etc.

[0105] As described in the embodiment, the control unit 240 performs wireless communication to which EN-DC (which may be NR-DC or NE-DC) is applied. The control unit 240 also receives information related to wireless communication from the base station 10, controls the wireless communication of the terminal 20 based on the information, and reports necessary information to the base station 10. 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. The control unit 240 sets information indicating one or more band combinations usable only for NE-DC in supportedBandCombinationListNEDC-Only, and the transmission unit 210 notifies the base station 10 of one or more band combinations usable only for the NE-DC by transmitting a signal including supportedBandCombinationListNEDC-Only to the base station 10.

[0106] (Hardware configuration) The block diagrams (FIGS. 17 and 18) 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.

[0107] 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.

[0108] For example, the base station 10, the terminal 20, etc. in an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 19 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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. 17 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. 18 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.

[0113] 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.

[0114] 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 Compact Disc ROM (CD-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.

[0115] 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.

[0116] 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).

[0117] 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.

[0118] 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.

[0119] (Summary of the embodiment) This specification discloses at least the following base station, network node, and communication method.

[0120] A network node having, in a terminal, a receiving unit that receives a signal including information indicating a first group consisting of one or more band combinations that can only be used for a specific dual connectivity and information indicating a second group consisting of one or more band combinations that can be used for the specific dual connectivity; a control unit that assigns a plurality of indexes corresponding to a plurality of band combinations of a third group consisting of a plurality of band combinations consisting of one or more band combinations of the first group and one or more band combinations of the second group, so that each band combination among the plurality of band combinations of the third group can be uniquely identified; and a transmitting unit that transmits a signal usable for communication between network nodes, including information indicating the plurality of band combinations of the third group, to another network node. A base station having, in a terminal, a receiving unit that receives capability information including information indicating a first group consisting of one or more band combinations usable only for a specific dual connectivity and information indicating a second group consisting of one or more band combinations usable for the specific dual connectivity; a control unit that assigns a plurality of indexes corresponding to a plurality of band combinations of a third group consisting of a plurality of band combinations consisting of one or more band combinations of the first group and one or more band combinations of the second group, so as to identify each band combination among the plurality of band combinations of the third group; and a transmitting unit that transmits a signal usable for communication between base stations, including the indexes, to another base station.

[0121] According to the above configuration, a master node that is notified of band combinations that can be used for an NE-DC by a terminal in the supportedBandCombinationList and supportedBandCombinationListNEDC-only fields can specify a band combination for a secondary cell group (SCG) in accordance with the multiple band combinations notified in the supportedBandCombinationList and supportedBandCombinationListNEDC-only fields.

[0122] The network node and / or base station may be a master node and support a New Radio (NR) communication method, and the other network node may be a secondary node and support a Long Term Evolution (LTE) communication method.

[0123] According to the above configuration, in the case of NE-DC, it becomes possible to set band combinations in cooperation between base stations.

[0124] The network nodes and / or base stations may be connected to a 5G-Core Network (5GC).

[0125] According to the above configuration, in the case of NE-DC, it becomes possible to set band combinations in cooperation between base stations.

[0126] The response signal received from the other network and / or the other base station may include information indicating a band combination selected by the other network node from among a plurality of band combinations of the third group.

[0127] According to the above configuration, in the case of NE-DC, the master node can set the band combination selected by the secondary node.

[0128] 1. A method for communicating by a network node, comprising: receiving, in a terminal, a signal including information indicating a first group consisting of one or more band combinations usable only for a specific dual connectivity and information indicating a second group consisting of one or more band combinations usable for the specific dual connectivity; assigning, for a third group consisting of a plurality of band combinations consisting of one or more band combinations of the first group and one or more band combinations of the second group, a plurality of indexes corresponding to a plurality of band combinations of the third group so that each band combination of the plurality of band combinations of the third group can be uniquely identified; and transmitting, to another network node, a signal usable for communication between network nodes, including information indicating the plurality of band combinations of the third group. A communication method by a base station, comprising: a step of receiving, in a terminal, capability information including information indicating a first group consisting of one or more band combinations usable only for a specific dual connectivity and information indicating a second group consisting of one or more band combinations usable for the specific dual connectivity; a step of assigning a plurality of indexes corresponding to a plurality of band combinations of a third group consisting of a plurality of band combinations consisting of one or more band combinations of the first group and one or more band combinations of the second group, so as to identify each band combination among the plurality of band combinations of the third group; and a step of transmitting, to another base station, a signal usable for communication between base stations, including the indexes.

[0129] According to the above configuration, a master node that has been notified by a terminal of a band combination that can only be used for an NE-DC in the supportedBandCombinationListNEDC-only field can specify a band combination for a secondary cell group (SCG) in accordance with one or more band combinations notified in the supportedBandCombinationListNEDC-only field.

[0130] (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.

[0131] In addition, 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. In addition, 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.

[0132] 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.

[0133] The steps, sequences, flow charts, 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.

[0134] 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).

[0135] 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.

[0136] 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.

[0137] 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).

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] The reference signal may be abbreviated as RS (Reference Signal) and may be called a pilot depending on the applicable standard.

[0155] 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."

[0156] 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.

[0157] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0158] 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.

[0159] 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.

[0160] 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."

[0161] 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).

[0162] 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.

[0163] This international patent application claims priority to Japanese Patent Application No. 2020-033804, filed on February 28, 2020, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0164] 10 base station 110 Transmitter 120 Receiving unit 130 Setting section 140 Control section 20 User device 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 in a terminal receives capability information including information indicating a first group consisting of one or more band combinations usable only for a specific dual connectivity and information indicating a second group consisting of one or more band combinations usable for the specific dual connectivity; a control unit that assigns a plurality of indexes corresponding to the plurality of band combinations of the third group, the plurality of band combinations being composed of one or more band combinations of the first group and one or more band combinations of the second group, so that a position of each of the plurality of band combinations of the third group can be specified within the third group; a transmitter for transmitting a signal including the index and usable for communication between base stations to another base station; A base station having

2. The base station is a master node and supports a New Radio (NR) communication method, The other base station is a secondary node and supports a Long Term Evolution (LTE) communication method. The base station according to claim 1 .

3. The base station is connected to a 5G-Core Network (5GC). The base station according to claim 2.

4. The response signal received from the other base station includes information indicating a band combination selected by the other base station from among the plurality of band combinations of the third group. The base station according to claim 1 .

5. Receiving capability information in a terminal, the capability information including information indicating a first group consisting of one or more band combinations usable only for a specific dual connectivity and information indicating a second group consisting of one or more band combinations usable for the specific dual connectivity; a step of assigning a plurality of indexes corresponding to the plurality of band combinations of the third group, the plurality of band combinations being composed of one or more band combinations of the first group and one or more band combinations of the second group, so that a position of each of the plurality of band combinations of the third group can be identified within the third group; transmitting a signal including the index and usable for communication between the base stations to another base station; A communication method by a base station comprising:

Images