Base station, communication device, and communication method

Abstract

When using dual connectivity in which an MN (200M) and an SN (200S) communicate with a UE (100), a base station (200) that operates as the MN (200M) sets a plurality of measurement gap patterns to the UE (100) and transmits MN setting gap information indicating the setting of each of the plurality of measurement gap patterns to the SN (200S) via a network interface.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on and claims the benefit of priority from Patent Application No. 2021-212778, filed December 27, 2021, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to a base station and a communication method used in a mobile communication system. [Background technology]

[0003] 3GPP (registered trademark; the same applies hereinafter) (3rd Generation Partnership Project), a standardization project for mobile communication systems, has introduced "measurement gaps" that periodically leave time gaps during which data communication is not scheduled so that user equipment (UE) in a radio resource control (RRC) connected state can measure communication quality in cells other than the serving cell and receive reference signals (RS) for location estimation. The base station notifies the UE of the setting of such measurement gap patterns via an RRC message.

[0004] Currently, 3GPP is discussing a method for setting multiple measurement gap patterns in a UE so that even if there are multiple measurement targets that the UE needs to measure, it can perform measurements using the optimal gap pattern for each measurement target (see, for example, Non-Patent Documents 1 and 2).

[0005] One scenario in which multiple measurement gap patterns are configured for a UE is Multi Radio Dual Connectivity (MR-DC), in which the UE communicates simultaneously with multiple nodes using different radio access technologies (RATs). In this type of dual connectivity (DC), the roles of the nodes communicating with the UE are divided into master nodes (MN) and secondary nodes (SN), and the MN has the initiative to determine the configuration for the UE, except for the configuration that is determined independently by the SN.

[0006] In MR-DC, in a configuration where the MN is an E-UTRA (Evolved Universal Terrestrial Radio Access) base station and the SN is an NR (NR Radio Access) base station, if the core network is EPC (Evolved Packet Core), it is called EN (E-UTRA NR)-DC, and if the core network is 5GC (5th Generation Core network), it is called NGEN (NG-RAN E-UTRA NR)-DC.

[0007] In EN-DC or NGEN-DC (hereinafter, collectively referred to as "(NG)EN-DC"), the MN basically configures the measurement gap pattern for the UE, but it is assumed that the SN configures the measurement gap pattern for a high frequency band called FR2 (Frequency Range 2) for the UE independently. Under this premise, it has been proposed that the MN and SN configure the measurement gap pattern for the UE in cooperation with each other (see Non-Patent Document 3). [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] 3GPP contribution: RP-211591 [Non-patent document 2] 3GPP contribution: R4-2115343 [Non-patent document 3] 3GPP contribution: R2-2109789 Summary of the Invention

[0009] For example, if multiple measurement targets are associated with the same measurement gap pattern in the MN and load concentration in the UE's measurement gap pattern is expected, it is efficient for the SN to configure the UE with a measurement gap pattern consisting of measurement gaps with timing different from that of the measurement gap pattern configured by the MN. Alternatively, depending on the situation, it may be preferable for the SN to configure the UE with a measurement gap pattern consisting of measurement gaps with timing identical to that of the measurement gap pattern configured by the MN.

[0010] In this way, it is considered that the SN can appropriately set a measurement gap pattern for the UE by understanding and considering each measurement gap pattern configured by the MN. However, in the current 3GPP technical specifications, the MN can notify the SN of only a single measurement gap pattern, and the SN cannot understand each measurement gap pattern configured by the MN.

[0011] Therefore, the present disclosure provides a base station and a communication method that enable a measurement gap pattern to be appropriately set in a UE even when each of an MN and an SN can set a measurement gap pattern in the UE.

[0012] A base station according to a first aspect is a base station that operates as a master node (MN) when a secondary node (SN) uses dual connectivity for communicating with a user equipment (UE), and includes: a control unit that configures a plurality of measurement gap patterns for the UE; and a network communication unit that transmits MN-configured gap information indicating the configuration of each of the plurality of measurement gap patterns to the SN via a network interface.

[0013] A base station according to a second aspect is a base station that operates as a master node (MN) and a secondary node (SN) when dual connectivity is used in which the SN communicates with a user equipment (UE). The base station includes a network communication unit that receives, from the MN via a network interface, MN-configured gap information indicating each of a plurality of measurement gap patterns that the MN has configured for the UE, and a control unit that determines at least one measurement gap pattern that the SN configures for the UE based on the MN-configured gap information.

[0014] A communication method according to a third aspect is a communication method for a base station operating as a master node (MN) and a secondary node (SN) when using dual connectivity for communicating with a user equipment (UE), the communication method comprising the steps of: configuring a plurality of measurement gap patterns for the UE; and transmitting MN-configured gap information indicating the configuration of each of the plurality of measurement gap patterns to the SN via a network interface.

[0015] A communication method according to a fourth aspect is a communication method for a base station operating as a master node (MN) and a secondary node (SN) when using dual connectivity for communication with a user equipment (UE), comprising the steps of: receiving, from the MN via a network interface, MN-configured gap information indicating each configuration of a plurality of measurement gap patterns configured by the MN in the UE; and determining, based on the MN-configured gap information, at least one measurement gap pattern to be configured in the UE by the SN. [Brief explanation of the drawings]

[0016] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings: [Figure 1] 1 is a diagram illustrating a configuration example of a mobile communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a protocol stack in the mobile communication system according to the embodiment. [Figure 3] FIG. 1 is a diagram illustrating a general measurement operation. [Figure 4] 4 is a diagram illustrating an example of the configuration of an RRC message in the measurement operation of FIG. 3. [Figure 5] FIG. 10 is a diagram illustrating the operation when multiple measurement gap patterns are configured for one UE. [Figure 6] 6 is a diagram illustrating an example of the configuration of an RRC message in the measurement operation of FIG. 5. [Figure 7] 6 is a diagram illustrating an example of the configuration of an RRC message in the measurement operation of FIG. 5. [Figure 8] 6 is a diagram illustrating an example of the configuration of an RRC message in the measurement operation of FIG. 5. [Figure 9] FIG. 1 is a diagram illustrating an overview of MR-DC. [Figure 10] FIG. 1 is a diagram illustrating an overview of MR-DC. [Figure 11] FIG. 1 is a diagram illustrating a configuration of a UE according to an embodiment. [Figure 12] FIG. 2 is a diagram illustrating a configuration of a base station according to an embodiment. [Figure 13] FIG. 1 is a diagram illustrating an example of operation of a mobile communication system according to an embodiment. [Figure 14] FIG. 2 is a diagram showing a first configuration example of MN setting gap information according to the embodiment. [Figure 15] FIG. 10 is a diagram showing a second configuration example of MN setting gap information according to the embodiment. [Figure 16] FIG. 10 is a diagram illustrating a first modified example of the operation of the mobile communication system according to the embodiment. [Figure 17] FIG. 10 is a diagram illustrating a second modified example of the operation of the mobile communication system according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] A mobile communication system according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0018] (Configuration of a mobile communication system) First, with reference to FIG. 1, the configuration of a mobile communication system 1 according to an embodiment will be described.

[0019] The mobile communication system 1 is, for example, a system that complies with the 3GPP Technical Specification (TS). In the following, the mobile communication system 1 will be mainly described as a mobile communication system based on NR (NR Radio Access), which is the radio access technology (RAT) of the 3GPP fifth generation (5G) system. However, the mobile communication system 1 may also have a configuration that is at least partially based on E-UTRA (Evolved Universal Terrestrial Radio Access) / LTE (Long Term Evolution), which is the RAT of the 3GPP fourth generation (4G) system.

[0020] The mobile communication system 1 includes a network 10 and a user equipment (UE) 100 that communicates with the network 10. The network 10 includes a radio access network (RAN) 20 and a core network (CN) 30. The RAN 20 is a next generation radio access network (NG-RAN) in 5G / NR. The RAN 20 may be an evolved universal terrestrial radio access network (E-UTRAN) in 4G / LTE. The CN 20 is a fifth generation core network (5GC) in 5G / NR. The CN 20 may be an evolved packet core (EPC) in 4G / LTE.

[0021] The UE 100 is a device used by a user. The UE 100 is a mobile device, such as a mobile phone terminal such as a smartphone, a tablet terminal, a laptop PC, a communication module, or a communication card. The UE 100 may be a vehicle (e.g., a car, a train, etc.) or a device provided therein. The UE 100 may be a transport vehicle other than a vehicle (e.g., a ship, an airplane, etc.) or a device provided therein. The UE 100 may be a sensor or a device provided therein. Note that the UE 100 may be called by other names such as a mobile station, a mobile terminal, a mobile device, a mobile unit, a subscriber station, a subscriber terminal, a subscriber device, a subscriber unit, a wireless station, a wireless terminal, a wireless device, a wireless unit, a remote station, a remote terminal, a remote device, or a remote unit.

[0022] The RAN 20 includes multiple base stations 200. Each base station 200 manages at least one cell. A cell constitutes the smallest unit of a communication area. For example, one cell belongs to one frequency (carrier frequency) and is composed of one component carrier. The term "cell" may refer to wireless communication resources or to a communication target of the UE 100. Each base station 200 can perform wireless communication with the UE 100 located in its own cell. The base station 200 communicates with the UE 100 using a protocol stack of the RAN. The base station 200 provides user plane and control plane protocol terminations for the UE 100 and is connected to the CN 30 via a base station-CN network interface. The base station 200 in 5G / NR is called a gNodeB (gNB), and the base station 200 in 4G / LTE is called an eNodeB (eNB). The base station-CN interface in 5G / NR is called an NG interface, and the base station-CN interface in 4G / LTE is called an S1 interface. Base station 200 is connected to neighboring base stations via a network interface between base stations. The interface between base stations in 5G / NR is called an Xn interface, and the interface between base stations in 4G / LTE is called an X2 interface.

[0023] The CN 30 includes a core network device 300. The core network device 300 is an Access and Mobility Management Function (AMF) and / or a User Plane Function (UPF) in 5G / NR. The core network device 300 may be a Mobility Management Entity (MME) and / or a Serving Gateway (S-GW) in 4G / LTE. The AMF / MME performs mobility management for the UE 100. The UPF / S-GW provides functions specialized for user plane processing.

[0024] An example of the configuration of a protocol stack in the mobile communication system 1 according to the embodiment will be described with reference to FIG.

[0025] The protocol for the wireless section between UE 100 and base station 200 includes a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a radio resource control (RRC) layer.

[0026] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the PHY layer of the UE 100 and the PHY layer of the base station 200 via a physical channel.

[0027] A physical channel consists of multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. One subframe consists of multiple OFDM symbols in the time domain. A resource block is a resource allocation unit and consists of multiple OFDM symbols and multiple subcarriers. A frame can be configured for 10 ms and can include 10 subframes, each of which is 1 ms long. A subframe can include the number of slots corresponding to the subcarrier spacing.

[0028] Among physical channels, the physical downlink control channel (PDCCH) plays a central role for purposes such as downlink scheduling assignment, uplink scheduling grant, and transmit power control. For example, the UE 100 performs blind decoding of the PDCCH using a Cell-Radio Network Temporary Identifier (C-RNTI) and a Modulation and Coding Scheme-C-RNTI (MCS-C-RNTI) or a Configured Scheduling-RNTI (CS-RNTI) assigned to the UE 100 by the base station 200, and acquires successfully decoded DCI as DCI addressed to the UE. Here, CRC parity bits scrambled by the C-RNTI and the MCS-C-RNTI or the CS-RNTI are added to the DCI transmitted from the base station 200.

[0029] In NR, the UE 100 can use a bandwidth narrower than the system bandwidth (i.e., the cell bandwidth). The base station 200 configures the UE 100 with a bandwidth part (BWP) consisting of consecutive PRBs. The UE 100 transmits and receives data and control signals in an active BWP. For example, up to four BWPs can be configured for the UE 100. Each BWP may have a different subcarrier spacing or may overlap in frequency. When multiple BWPs are configured for the UE 100, the base station 200 can specify which BWP to activate by controlling downlink. This allows the base station 200 to dynamically adjust the UE bandwidth according to the amount of data traffic of the UE 100, etc., and can reduce UE power consumption.

[0030] For example, base station 200 can configure up to three control resource sets (CORESETs) for each of up to four BWPs on the serving cell. A CORESET is a radio resource for control information to be received by UE 100. Up to 12 CORESETs can be configured for UE 100 on the serving cell. Each CORESET has an index of 0 to 11. For example, a CORESET consists of six resource blocks (PRBs) and one, two, or three consecutive OFDM symbols in the time domain.

[0031] The MAC layer performs data priority control, retransmission processing using Hybrid Automatic Repeat reQuest (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of UE 100 and the MAC layer of base station 200 via a transport channel. The MAC layer of base station 200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resources to be allocated to UE 100.

[0032] The RLC layer transmits data to the RLC layer on the receiving side using the functions of the MAC layer and PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the base station 200 via logical channels.

[0033] The PDCP layer performs header compression / decompression and encryption / decryption.

[0034] An SDAP (Service Data Adaptation Protocol) layer may be provided above the PDCP layer, which maps IP flows, which are units for Quality of Service (QoS) control by the core network, to radio bearers, which are units for QoS control by the AS (Access Stratum).

[0035] The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, re-establishment, and release of radio bearers. RRC signaling for various settings is transmitted between the RRC layer of the UE 100 and the RRC layer of the base station 200. When there is an RRC connection between the RRC of the UE 100 and the RRC of the base station 200, the UE 100 is in an RRC connected state. When there is no RRC connection between the RRC of the UE 100 and the RRC of the base station 200, the UE 100 is in an RRC idle state. When the RRC connection between the RRC of the UE 100 and the RRC of the base station 200 is suspended, the UE 100 is in an RRC inactive state.

[0036] The NAS layer, which is located above the RRC layer, performs session management and mobility management for the UE 100. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the core network device 300 (AMF / MME). Note that the UE 100 has an application layer and the like in addition to a radio interface protocol.

[0037] (Overview of measurement operations by UE) Next, an overview of the measurement operation by the UE 100 will be described with reference to FIGS.

[0038] 3 is a diagram showing a general measurement operation. The UE 100 is in an RRC connected state. The UE 100 communicates with the base station 200 in a serving cell managed by the base station 200.

[0039] In step S1, the base station 200 generates an RRC message including a measurement configuration for the UE 100. The RRC message is, for example, an RRC reconfiguration message or an RRC resume message, but the following description will be given taking the RRC reconfiguration message as an example. The RRC reconfiguration message is a message for changing the RRC connection.

[0040] As shown in FIG. 4(1), the RRC message (for example, RRCReconfiguration) includes a measurement configuration (MeasConfig) that specifies measurements that the UE 100 should perform.

[0041] 4(2), the measurement configuration (MeasConfig) includes a list of measurement objects to be added and / or changed (MeasObjectToAddModList), a list of measurement report configurations to be added and / or changed (ReportConfigToAddModList), a list of measurement identifiers to be added and / or changed (MeasIdToAddModList), and a measurement gap configuration (MeasGapConfig). The measurement configuration may also include a list of measurement objects to be removed (MeasObjectToRemoveList), a list of measurement report configurations to be removed (ReportConfigToRemoveList), and a list of measurement identifiers to be removed (MeasIdToRemoveList).

[0042] The list of measurement objects (MeasObjectToAddModList) may include multiple measurement object configurations (MeasObjectToAddMod) that specify measurement objects. The measurement object configuration includes a set of a measurement object identifier (MeasObjectId) and measurement object information (measObject). The measurement object identifier is used to identify the measurement object configuration. The measurement object information may be information that specifies, for example, a frequency, a reference signal, etc. The reference signal may be at least one of a synchronization signal and a physical broadcast channel block (SSB) that are composed of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH), a channel state information reference signal (CSI-RS), and a positioning reference signal (PRS). The measurement object configuration includes, for example, a measurement object configuration (MeasObjectNR) that specifies information applicable to SS / PBCH block intra-frequency / inter-frequency measurements and / or CSI-RS intra-frequency / inter-frequency measurements.

[0043] The measurement reporting configuration list (ReportConfigToAddModList) may include multiple measurement reporting configurations (ReportConfigToAddMod). A measurement reporting configuration includes a set of a reporting configuration identifier (ReportConfigId) and a measurement reporting configuration (reportConfig). The reporting configuration identifier is used to identify the measurement reporting configuration. The measurement reporting configuration may specify criteria that trigger reporting of measurement results.

[0044] As shown in Figure 4 (3), the measurement identifier list (MeasIdToAddModList) includes a set of a measurement identifier (MeasId), a measurement object identifier (MeasObjectId), and a report configuration identifier (ReportConfigId). Therefore, a measurement identifier is associated with a combination of a measurement object configuration and a measurement report configuration via the measurement object identifier and the report configuration identifier. In this way, the measurement objects and the configuration related to reporting of the measurement results are each configured in a separate list, and are made valid by being linked by the measurement identifier (MeasId).

[0045] The measurement gap configuration (MeasGapConfig) is used to set up and release a measurement gap pattern. A measurement gap pattern consists of measurement gaps where communication can be interrupted. The measurement gap configuration may include gapOffset, mgl, mgrp, and mgta. mgl is the measurement gap length of the measurement gap. mgrp is the measurement gap repetition period (MGRP) of the measurement gap. mgta is the measurement gap timing advance. gapOffset is the gap offset of the measurement gap pattern with MGRP.

[0046] 3, in step S2, UE 100, which has received the RRC message, performs measurement on the measurement target based on the measurement configuration included in the received RRC message. Here, UE 100 performs measurement on the measurement target set based on the measurement target configuration in the measurement gap set based on the measurement gap configuration.

[0047] In step S3, the UE 100 transmits a measurement report including the measurement result in step S2 to the base station 200. When a measurement report is triggered based on the measurement report configuration, the UE 100 transmits the measurement report to the base station 200. The base station 200 receives the measurement report from the UE 100.

[0048] In recent years, a method of setting a plurality of measurement gap patterns to the UE 100 has been discussed so that even when there are a plurality of measurement targets to be measured by the UE 100, measurements can be performed with an optimal measurement gap pattern for each measurement target. The case where a plurality of measurement gap patterns are set for one UE 100 is sometimes referred to as "multiple concurrent and independent MG patterns."

[0049] 5 is a diagram showing an operation of setting a plurality of measurement gap patterns for one UE 100. Here, differences from the general measurement operation described above will be mainly explained.

[0050] As shown in FIG. 5, in step S11, the base station 200 transmits an RRC message to the UE 100.

[0051] 6, the measurement configuration (MeasConfig) included in the RRC message includes a list of measurement gap configurations to be added and / or modified (MeasGapToAddModList). The measurement configuration may include a list of measurement gap identifiers to be removed (MeasGapToRemoveList).

[0052] The measurement gap configuration list (MeasGapToAddModList) includes a measurement gap identifier (MeasGapId) and a set (MeasGapToAddMod) of multiple measurement gap configurations (MeasGapConfig). The measurement gap identifier is used to identify a measurement gap configuration (measurement gap pattern).

[0053] The RRC message also includes a set of measurement identifiers and measurement gap identifiers. As shown in Figures 7 and 8, the list of measurement identifiers (MeasIdToAddMod) includes a set (MeasIdToAddMod) of a measurement identifier (MeasId) and a measurement gap identifier (MeasGapId). The set further includes a measurement object identifier (MeasObjectId) and a reporting configuration identifier (reportConfigId). This associates the measurement gap identifier with the measurement identifier. As a result, each of the multiple measurement configurations is associated with the measurement identifier via the measurement gap identifier.

[0054] As shown in FIG. 6, the measurement configuration may include an existing measurement gap configuration (MeasGapConfig) in addition to the list of measurement gap configurations. The existing measurement gap configuration may be treated as one of multiple measurement gap configurations. A measurement gap configuration in the list of measurement gap configurations may be treated as the second or subsequent measurement gap configuration. Alternatively, the existing measurement gap configuration may not be usable when the RRC message includes the list of measurement gap configurations. Furthermore, the existing measurement gap configuration may be usable only when the UE 100 does not support the configuration of multiple gap patterns. When the UE 100 supports the configuration of multiple gap patterns, the existing measurement gap configuration may not be usable.

[0055] Base station 200 associates measurement gap configurations with measurement identifiers so that each frequency layer is associated with only one gap pattern. Even if the frequency layer is the same, if the reference signals to be measured (e.g., SSB, CSI-RS, PRS) are different, they may be treated as different frequency layers.

[0056] Returning to FIG. 5, in step S12, UE 100 that has received the RRC message performs measurement on the measurement object. Specifically, UE 100 performs measurement on the measurement object set based on the measurement object configuration in measurement gaps of multiple measurement gap patterns set based on multiple measurement gap configurations. In this way, multiple gap patterns are set for UE 100 based on multiple measurement gap configurations. Specifically, when UE 100 performs measurement on a specific measurement object, it performs measurement using a measurement gap pattern based on a measurement gap configuration associated with a measurement identifier associated with the specific measurement object. Here, UE 100 performs measurement on the measurement object based on the measurement object configuration associated with the measurement identifier via the measurement gap identifier, using the measurement gap pattern based on the measurement gap configuration associated with the measurement identifier via the measurement gap identifier.

[0057] In step S13, the UE 100 transmits a measurement report including the measurement result in step S12 to the base station 200. When a measurement report is triggered based on the measurement report configuration, the UE 100 transmits the measurement report to the base station 200. The base station 200 receives the measurement report from the UE 100.

[0058] (MR-DC Overview) Next, an overview of MR-DC will be described with reference to FIGS.

[0059] As shown in Figure 9, in MR-DC, the UE 100 simultaneously communicates with a master cell group (MCG) 201M managed by a master node (MN) 200M and a secondary cell group (SCG) 201S managed by a secondary node (SN) 200S. The MN 200M may be an NR base station (gNB) or an LTE base station (eNB). The MN 200M is also referred to as a master base station. The SN 200S may be an NR base station (gNB) or an LTE base station (eNB). The SN 200S is also referred to as a secondary base station.

[0060] For example, the MN 200M transmits a predetermined message (for example, an SN Addition Request message) to the SN 200S, and the MN 200M transmits an RRC Reconfiguration message to the UE 100, thereby starting the DC.

[0061] The UE 100 in the RRC connected state is assigned radio resources by the respective schedulers of the MN 200M and the SN 200S, which are connected to each other via a network interface, and performs radio communication using the radio resources of the MN 200M and the radio resources of the SN 200S. The network interface between the MN 200M and the SN 200 may be an Xn interface or an X2 interface. The MN 200M and the SN 200 communicate with each other via this network interface.

[0062] The MN 200M may have a control plane connection with a core network. The MN 200M provides primary radio resources for the UE 100. The MN 200M manages the MCG 201M. The MCG 201M is a group of serving cells associated with the MN 200M. The MCG 201M has a primary cell (PCell) and optionally has one or more secondary cells (SCells).

[0063] The SN200S may not have a control plane connection with the core network. The SN200S provides additional radio resources to the UE100. The SN200S manages the SCG201S. The SCG201S has a primary and secondary cell (PSCell) and optionally has one or more SCells. The PCell of the MCG201M and the PSCell of the SCG201S are also called special cells (SpCells).

[0064] In this way, in DC (MR-DC), the roles of the nodes communicating with the UE 100 are divided between the MN 200M and the SN 200S, and the MN 200M has the initiative to determine the settings for the UE 100, except for the settings that are determined independently by the SN 200S.

[0065] As shown in Fig. 10, in MR-DC, a configuration in which MN200M is an E-UTRA base station and SN200S is an NR base station is called (NG)EN-DC. Specifically, when CN30 is EPC, a configuration in which MN200M is an E-UTRA base station (eNB) and SN200S is an NR base station (en-gNB) is called EN-DC. Also, when CN30 is 5GC, a configuration in which MN200M is an E-UTRA base station (ng-eNB) and SN200S is an NR base station (gNB) is called NGEN-DC.

[0066] When the CN30 is 5GC, a configuration in which the MN200M is an NR base station (gNB) and the SN200S is an E-UTRA base station (ng-eNB) is called NE-DC. Also, when the CN30 is 5GC, a configuration in which the MN200M is an NR base station (gNB) and the SN200S is also an NR base station (gNB) is called NR-DC.

[0067] In (NG)EN-DC, the MN 200M basically sets the measurement gap pattern for the UE 100, but it is assumed that the SN 200S independently sets the measurement gap pattern for the high frequency band called FR2 (Frequency Range 2) for the UE 100.

[0068] For example, when multiple measurement targets are associated with the same measurement gap pattern in the MN 200M and load concentration in the measurement gap pattern of the UE 100 is expected, it is efficient for the SN 200S to set, for the UE 100, a measurement gap pattern consisting of measurement gaps whose timing is different from that of the measurement gap pattern set by the MN 200M. Alternatively, depending on the situation, it may be preferable for the SN 200S to set, for the UE 100, a measurement gap pattern consisting of measurement gaps whose timing is the same as that of the measurement gap pattern set by the MN 200M. In this way, it is considered that the SN 200S can appropriately set a measurement gap pattern for the UE 100 by grasping and considering each measurement gap pattern set by the MN 200M.

[0069] In the following, a scenario in which a plurality of measurement gap patterns are set for the UE 100 (multiple concurrent and independent MG patterns) will be mainly described under the assumption that (NG)EN-DC is applied.

[0070] (Configuration of user device) Next, a configuration of the UE 100 according to the embodiment will be described with reference to Fig. 11. The UE 100 includes a communication unit 110 and a control unit 120.

[0071] The communication unit 110 performs wireless communication with the base station 200 by transmitting and receiving radio signals to and from the base station 200. The communication unit 110 has at least one transmission unit 111 and at least one reception unit 112. The transmission unit 111 and the reception unit 112 may be configured to include multiple antennas and RF circuits. The antenna converts a signal into radio waves and radiates the radio waves into space. The antenna also receives radio waves in space and converts the radio waves into a signal. The RF circuit performs analog processing of the signal transmitted and received via the antenna. The RF circuit may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, etc.

[0072] The control unit 120 performs various controls in the UE 100. The control unit 120 controls communication with the base station 200 via the communication unit 110. The operations of the UE 100 described above and below may be controlled by the control unit 120. The control unit 120 may include at least one processor capable of executing a program and a memory that stores the program. The processor may execute the program to perform the operations of the control unit 120. The control unit 120 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and the RF circuit. The digital processing includes processing of a RAN protocol stack. The memory stores programs executed by the processor, parameters related to the programs, and data related to the programs. The memory may include at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), and a flash memory. All or a part of the memory may be included in the processor.

[0073] In UE 100 configured in this manner, communication unit 110 receives from base station 200 an RRC message including multiple measurement gap configurations for configuring multiple measurement gap patterns each configured by measurement gaps in which communication can be interrupted. Control unit 120 performs measurements on measurement targets in the measurement gaps configured based on the multiple measurement gap configurations. In the RRC message, each of the multiple measurement gap configurations is associated with at least one measurement identifier associated with a combination of a measurement target configuration and a measurement report configuration. Control unit 120 performs measurements based on the measurement target configuration associated with the measurement identifier in the measurement gaps that configure the measurement gap pattern based on the measurement gap configuration associated with the measurement identifier.

[0074] In an embodiment, the communication unit 110 may receive an RRC message for setting a measurement gap pattern from each of the MN 200M and the SN 200S. That is, the UE 100 may be set with a measurement gap pattern from each of the MN 200M and the SN 200S. The UE 100 (control unit 120) performs measurement on a measurement target in each measurement gap in each measurement gap pattern set by each of the MN 200M and the SN 200S.

[0075] (Base station configuration) Next, the configuration of the base station 200 according to this embodiment will be described with reference to Fig. 12. The base station 200 includes a communication unit 210, a network communication unit 220, and a control unit 230.

[0076] The communication unit 210 receives a radio signal from the UE 100 and transmits the radio signal to the UE 100, for example. The communication unit 210 has at least one transmission unit 211 and at least one reception unit 212. The transmission unit 211 and the reception unit 212 may be configured to include an RF circuit. The RF circuit performs analog processing of a signal transmitted and received via an antenna. The RF circuit may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, etc.

[0077] The network communication unit 220 transmits and receives signals to and from the network. For example, the network communication unit 220 receives signals from neighboring base stations connected via an Xn interface or an X2 interface, which are base station-to-base station interfaces, and transmits the signals to the neighboring base stations. The network communication unit 220 also receives signals from the core network device 300 connected via an NG interface or an S1 interface, and transmits the signals to the core network device 300.

[0078] The control unit 230 performs various controls in the base station 200. The control unit 230 controls, for example, communication with the UE 100 via the communication unit 210. The control unit 230 also controls, for example, communication with a node (e.g., a neighboring base station, the core network device 300) via the network communication unit 220. The operations of the base station 200 described above and below may be operations controlled by the control unit 230. The control unit 230 may include at least one processor capable of executing a program and a memory that stores the program. The processor may execute the program to perform the operations of the control unit 230. The control unit 230 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and the RF circuit. The digital processing includes processing of a protocol stack of the RAN. The memory stores the program executed by the processor, parameters related to the program, and data related to the program. All or a part of the memory may be included in the processor.

[0079] The base station 200 configured in this manner may operate as the MN 200M when using MR-DC. Specifically, the base station 200 may be an E-UTRA base station operating as the MN 200M in (NG)EN-DC. In such a base station 200, the control unit 230 configures multiple measurement gap patterns for the UE 100. The network communication unit 220 transmits MN-configured gap information indicating the configuration of each of the multiple measurement gap patterns to the SN 200S via the network interface. This allows the SN 200S to grasp and consider each measurement gap pattern configured by the MN 200M, even if each of the MN 200M and the SN 200S can configure a measurement gap pattern for the UE 100. Therefore, the SN 200S can appropriately configure a measurement gap pattern for the UE 100.

[0080] Alternatively, the base station 200 may operate as the SN 200S when using MR-DC. Specifically, the base station 200 may be an NR base station operating as the SN 200S in (NG)EN-DC. In such a base station 200, the network communication unit 220 receives, from the MN 200M via a network interface, MN-configured gap information indicating each of multiple measurement gap patterns configured by the MN 200M for the UE 100. The control unit 230 determines at least one measurement gap pattern to be configured for the UE 100 by the SN 200S based on the MN-configured gap information. As a result, even if each of the MN 200M and the SN 200S can configure a measurement gap pattern for the UE 100, the SN 200S can grasp and consider each measurement gap pattern configured by the MN 200M and appropriately configure a measurement gap pattern for the UE 100.

[0081] (Example of operation of a mobile communication system) Next, the operation of the mobile communication system 1 according to the embodiment will be described with reference to FIGS.

[0082] FIG. 13 is a diagram showing an example of the operation of the mobile communication system 1 according to the embodiment.

[0083] In step S101, the MN 200M (transmitter 211) transmits an RRC message including measurement configuration for setting a plurality of measurement gap patterns to the UE 100. For example, the measurement gap pattern that the MN 200M sets to the UE 100 may be a measurement gap pattern for a purpose (target) other than FR2. The "purpose" of a measurement gap pattern may be referred to as the "use case" of the measurement gap pattern.

[0084] In step S102, the MN 200M (network communication unit 220) transmits MN-configured gap information indicating the configuration of each measurement gap pattern configured in the UE 100 in step S101 to the SN 200S via a network interface (specifically, an inter-base station interface). The SN 200S (network communication unit 220) receives the MN-configured gap information.

[0085] The MN configuration gap information is composed of information elements included in an inter-base station message transmitted on the inter-base station interface. Such an inter-base station message may be an SN addition request message for adding an SN 200S when starting DC, or an SN modification request message for modifying the configuration of the SN 200S after starting DC. The information elements constituting the MN configuration gap information may be CG-ConfigInfo, which is a type of inter-node RRC message used for establishing or modifying an SCG, or may be information elements newly introduced into inter-base station messages. In the following, an example in which the information element constituting the gap upper limit information is CG-ConfigInfo will be mainly described.

[0086] In step S103, the SN 200S (control unit 230) determines at least one measurement gap pattern to be set by the SN 200S to the UE 100 based on the MN-configured gap information received in step S102. For example, when a plurality of measurement targets are associated with the same measurement gap pattern in the MN 200M and load concentration during the measurement gap of the UE 100 is expected, the SN 200S (control unit 230) may determine to set to the UE 100 a measurement gap pattern consisting of measurement gaps with timing different from that of the measurement gap pattern set by the MN 200M. Alternatively, as in a modified example described later, when the SN 200S wants to reuse the measurement gap pattern set by the MN 200M, it may determine to set to the UE 100 the same measurement gap pattern as the measurement gap pattern set by the MN 200M.

[0087] In step S104, the SN 200S (transmitter 211) transmits an RRC message including a measurement configuration for setting the measurement gap pattern determined in step S103 to the UE 100. For example, the measurement gap pattern that the SN 200S sets to the UE 100 may be a measurement gap pattern aimed at FR2.

[0088] As described above, according to the embodiment, the SN 200S can grasp multiple measurement gap patterns set by the MN 200M. Therefore, depending on the situation, it is possible to ensure optimal performance by overlapping or shifting the timing of the measurement gaps in the measurement gap pattern set by the SN 200S with respect to the measurement gap pattern set by the MN 200M.

[0089] (1) First configuration example of MN setting gap information FIG. 14 is a diagram illustrating a first configuration example of MN-configured gap information according to the embodiment.

[0090] As described above, the MN 200M (transmitter 211) transmits an RRC message including a measurement configuration for setting multiple measurement gap patterns to the UE 100. In this configuration example, the MN 200M (network communication unit 220) transmits the measurement configuration transmitted to the UE 100 to the SN 200S as MN-configured gap information. The SN 200S (network communication unit 220) receives the measurement configuration transmitted from the MN 200M to the UE 100 as MN-configured gap information from the MN 200M. This allows the SN 200S to grasp the overall measurement configuration including the multiple measurement gap patterns transmitted from the MN 200M to the UE 100. This allows the SN 200S to appropriately set the measurement gap pattern to the UE 100.

[0091] 14, the CG-ConfigInfo transmitted from the MN 200M to the SN 200S includes "CG-Config-v17xy-IEs" which corresponds to MN configuration gap information indicating the configuration of each measurement gap pattern configured in the UE 100. The "CG-Config-v17xy-IEs" includes the measurement configuration (MeasConfig) configured in the UE 100 by the MN 200M.

[0092] (2) Second Configuration Example of MN Configuration Gap Information FIG. 15 is a diagram illustrating a second configuration example of the MN setting gap information according to the embodiment.

[0093] In this configuration, the MN 200M (network communication unit 220) transmits, as MN-configured gap information, part of the measurement configuration (MeasConfig) transmitted to the UE 100, configuration information individual to each of a plurality of measurement gap patterns configured by the MN 200M in the UE 100. That is, the MN 200M (network communication unit 220) transmits, as MN-configured gap information, information elements obtained by extracting only the minimum information necessary for the SN 200S to configure a measurement gap pattern from the information included in MeasConfig. The SN 200S (network communication unit 220) receives, from the MN 200M, part of the measurement configuration information transmitted by the MN 200M to the UE 100, configuration information individual to each of a plurality of measurement gap patterns. This makes it possible to reduce the size (message size) of the MN-configured gap information compared to the first configuration example described above.

[0094] As shown in Fig. 15, the CG-ConfigInfo transmitted from the MN 200M to the SN 200S includes "CG-Config-v17xy-IEs" corresponding to MN configuration gap information indicating the configuration of each measurement gap pattern configured in the UE 100. "CG-Config-v17xy-IEs" includes "measConfigSNList-r17", which is a new information element that lists "MeasConfigSN-r17", which is configuration information individual to each measurement gap pattern configured in the UE 100 by the MN 200M. "MeasConfigSN-r17" includes at least one information element out of "RAT-Type" indicating the RAT type, "ARFCN-ValueEUTRA" indicating the carrier frequency, the measurement gap configuration "measGapConfig", and "gapPurpose" indicating the purpose (target) of the measurement gap pattern, as parameters of the corresponding measurement gap pattern. "gapPurpose" is set to, for example, one of "perUE", which is a measurement gap pattern set per UE, "perFR1", which indicates that FR1 (Frequency Range 1) is the target, "perFR2", which indicates that FR2 (Frequency Range 2) is the target, and "forPRS", which indicates that the positioning reference signal (PRS) is the target.

[0095] (First modified example of operation of mobile communication system) Next, a first modification of the operation of the mobile communication system 1 will be described with reference to FIG.

[0096] In this modification, a measurement gap identifier is assigned to each measurement gap pattern. The MN-configured gap information transmitted from the MN 200M to the SN 200S includes the measurement gap identifiers of the multiple measurement gap patterns configured by the MN 200M in the UE 100. This allows the SN 200S to grasp not only each measurement gap pattern configured by the MN 200M in the UE 100, but also the measurement gap identifiers of the measurement gap patterns.

[0097] As described above, the SN 200S (transmitting unit 211) transmits to the UE 100 an RRC message including information (measurement configuration) for setting a measurement gap pattern determined by the SN 200S. Here, when the SN 200S sets to the UE 100 a measurement gap pattern selected from a plurality of measurement gap patterns set to the UE 100 by the MN 200M, the SN 200S (transmitting unit 211) may transmit an RRC message including a measurement gap identifier of the selected measurement gap pattern. That is, when the SN 200S sets to the UE 100 the same measurement gap pattern as the measurement gap pattern set to the UE 100 by the MN 200M, the SN 200S notifies the UE 100 of the measurement gap identifier of the same measurement gap pattern. As a result, when the SN 200S uses the same configuration as the measurement gap pattern already set to the UE 100 from the MN 200M, it is not necessary to send the actual configuration of the measurement gap pattern, and it is sufficient to send the measurement gap identifier of the measurement gap pattern to the UE 100, thereby reducing the consumption of radio resources and power.

[0098] In this modification, the ID space of measurement gap identifiers (measurement gap identifier space) may be divided between the MN 200M and the SN 200S, thereby enabling the SN 200S to set its own measurement gap identifier. For example, if the maximum number of IDs is 64, 0 to 31 may be defined for the MN 200M, and 32 to 63 may be defined for the SN 200S. In this way, when a measurement gap identifier space allocatable by the SN 200S is provided independently of a measurement gap identifier space allocatable by the MN 200M, the SN 200S (control unit 230) may allocate a measurement gap identifier from the measurement gap identifier space allocatable by the SN 200S. Similarly, when a measurement gap identifier space allocatable by the MN 200M is provided independently of a measurement gap identifier space allocatable by the SN 200S, the MN 200M (control unit 230) may allocate a measurement gap identifier from the measurement gap identifier space allocatable by the MN 200M.

[0099] As shown in FIG. 16, in step S101, the MN 200M (transmitter 211) transmits to the UE 100 an RRC message including a measurement configuration for setting a plurality of measurement gap patterns.

[0100] In step S102a, the MN 200M (network communication unit 220) transmits MN-configured gap information indicating the configuration of each measurement gap pattern configured in the UE 100 in step S101 to the SN 200S via a network interface (specifically, an inter-base station interface). The MN-configured gap information includes a measurement gap identifier for each measurement gap pattern in addition to the configuration contents of each measurement gap pattern configured in the UE 100 by the MN 200M (see FIGS. 14 and 15). The SN 200S (network communication unit 220) receives the MN-configured gap information.

[0101] In step S103, the SN 200S (control unit 230) determines at least one measurement gap pattern that the SN 200S sets in the UE 100 based on the MN-set gap information received in step S102a.

[0102] For example, the SN 200S (control unit 230) may decide to configure a measurement gap pattern consisting of measurement gaps whose timing differs from that of the measurement gap pattern configured by the MN 200M, in the UE 100. In this case, the SN 200S (control unit 230) may configure a measurement gap identifier assigned by the SN 200S from a measurement gap identifier space that can be assigned, in the UE 100 together with the measurement gap configuration (step S104a).

[0103] Alternatively, when the SN 200S wants to use the measurement gap pattern set by the MN 200M, the SN 200S (control unit 230) may set a measurement gap identifier of the measurement gap pattern to the UE 100 (step S104a). Here, the SN 200S (control unit 230) may associate the measurement gap identifier with a measurement target.

[0104] (Second modified example of operation of mobile communication system) Next, a second modification of the operation of the mobile communication system 1 will be described with reference to FIG.

[0105] In this modified example, the SN 200S (network communication unit 220) transmits SN configuration gap information indicating the configuration of one or more measurement gap patterns configured by the SN 200S to the UE 100 to the MN 200M via a network interface. The MN 200M (network communication unit 220) receives SN configuration gap information indicating the configuration of one or more measurement gap patterns configured by the SN 200S to the UE 100 from the SN 200S via a network interface. This allows the MN 200M to grasp and consider each measurement gap pattern configured by the SN 200S, even if each of the MN 200M and the SN 200S can configure a measurement gap pattern to the UE 100. Therefore, the MN 200M can appropriately configure a measurement gap pattern to the UE 100. For example, the MN 200M (control unit 230) may perform processing such as not performing data scheduling during a measurement gap of a measurement gap pattern configured by the SN 200S.

[0106] As shown in FIG. 17, the operations in steps S101 to S104 are the same as those in the above-described embodiment.

[0107] In step S201, the SN 200S (network communication unit 220) transmits SN setting gap information indicating the setting of each of one or more measurement gap patterns that the SN 200S has set in the UE 100 (step S104) to the MN 200M via the network interface.

[0108] The SN configuration gap information is composed of information elements included in an inter-base station message transmitted on the inter-base station interface. Such an inter-base station message may be an acknowledgement message to an SN addition request message, or an SN modification request message for modifying the configuration of the SN 200S after starting DC. The information elements constituting the SN configuration gap information may be CG-Config, which is a type of inter-node RRC message used to request SCG configuration, or may be information elements newly introduced into the inter-base station message.

[0109] The SN setting gap information may have a configuration similar to either the first or second configuration example of the SN setting gap information described above. For example, the SN 200S (network communication unit 220) may transmit the measurement configuration set in the UE 100 in step S104 to the MN 200M as the SN setting gap information. Alternatively, the SN 200S (network communication unit 220) may transmit the minimum necessary information (see FIG. 15) of the measurement configuration set in the UE 100 in step S104 to the MN 200M as the SN setting gap information.

[0110] In this way, according to this modified example, MN200M can also understand the measurement gap pattern set by SN200S, thereby avoiding waste of radio resources and power, such as MN200M scheduling data while UE100 is executing the measurement gap pattern for SN200S.

[0111] (Other embodiments) In the above-described embodiment, an example using (NG)EN-DC has been mainly described. However, as long as the SN 200S independently sets the measurement gap pattern to the UE 100, the present invention is not limited to (NG)EN-DC and may be applied to DCs other than (NG)EN-DC.

[0112] Although the example in which the MN 200M is an E-UTRA base station has been mainly described, the MN 200M may be an NR base station. Similarly, the example in which the SN 200S is an NR base station has been mainly described, but the SN 200S may be an E-UTRA base station.

[0113] In the above embodiment, dual connectivity (DC) in which the UE 100 communicates with two base stations is described, but the UE 100 may have multiple connections with three or more base stations 200, including two or more SNs 200S, and such multiple connections may also be a form of DC.

[0114] The operational sequences (and operational flows) in the above-described embodiments do not necessarily have to be executed in chronological order according to the order depicted in the flow diagrams or sequence diagrams. For example, the steps in the operations may be executed in an order different from that depicted in the flow diagrams or sequence diagrams, or may be executed in parallel. Some of the steps in the operations may be deleted, or additional steps may be added to the processing. The operational sequences (and operational flows) in the above-described embodiments may be executed independently, or two or more operational sequences (and operational flows) may be executed in combination. For example, some steps in one operational flow may be added to another operational flow, or some steps in one operational flow may be replaced with some steps in another operational flow.

[0115] In the above-described embodiments, the mobile communication system 1 has been mainly described as an NR-based mobile communication system. However, the mobile communication system 1 is not limited to this example. The mobile communication system 1 may be a system compliant with a TS of either LTE or another generation system (e.g., 6th generation) of the 3GPP standard. The base station 200 may be an eNB that provides E-UTRA user plane and control plane protocol termination toward the UE 100 in LTE. The mobile communication system 1 may be a system compliant with a TS of a standard other than the 3GPP standard. The base station 200 may be an IAB (Integrated Access and Backhaul) donor or an IAB node.

[0116] A program may be provided that causes a computer to execute each process performed by the UE 100 or the base station 200. The program may be recorded in a computer-readable medium. Using the computer-readable medium, the program can be installed in a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM. Furthermore, circuits that execute each process performed by the UE 100 or the base station 200 may be integrated, and at least a part of the UE 100 or the base station 200 may be configured as a semiconductor integrated circuit (chip set, SoC (System-on-a-Chip)).

[0117] In the above embodiments, "transmit" may mean performing processing at least one layer in a protocol stack used for transmission, or may mean physically transmitting a signal wirelessly or via a wired connection. Alternatively, "transmit" may mean a combination of performing processing at least one layer and physically transmitting a signal wirelessly or via a wired connection. Similarly, "receive" may mean performing processing at least one layer in a protocol stack used for reception, or may mean physically receiving a signal wirelessly or via a wired connection. Alternatively, "receive" may mean a combination of performing processing at least one layer and physically receiving a signal wirelessly or via a wired connection. Similarly, "obtain / acquire" may mean obtaining information from stored information, obtaining information from information received from another node, or obtaining information by generating the information. Similarly, "include" and "comprise" do not mean including only the enumerated items, but may mean including only the enumerated items or including additional items in addition to the enumerated items. Similarly, in this disclosure, "or" does not mean an exclusive or, but rather a logical or.

[0118] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0119] (Addendum) The following additional notes are about the features of the above-described embodiment.

[0120] (Appendix 1) A base station (200) that operates as a master node (MN) (200M) when a secondary node (SN) (200S) uses dual connectivity to communicate with a user equipment (UE) (100), a control unit (230) that sets a plurality of measurement gap patterns for the UE (100); a network communication unit (220) that transmits MN setting gap information indicating the setting of each of the plurality of measurement gap patterns to the SN (200S) via a network interface. Base station (200).

[0121] (Appendix 2) The MN (200M) is an E-UTRA (Evolved Universal Terrestrial Radio Access) base station (200), and the SN (200S) is an NR (NR Radio Access) base station (200). 2. The base station (200) according to claim 1.

[0122] (Appendix 3) A transmitter (211) is further provided which transmits a radio resource control (RRC) message including a measurement configuration for setting the plurality of measurement gap patterns to the UE (100), The network communication unit (220) transmits the measurement configuration transmitted to the UE (100) as the MN configuration gap information to the SN (200S). 3. The base station (200) according to claim 1 or 2.

[0123] (Appendix 4) The network communication unit (220) transmits to the SN (200S) as the MN configuration gap information, the measurement configuration information being part of the information transmitted to the UE (100), and being individual configuration information for each of the plurality of measurement gap patterns. 4. The base station (200) according to claim 3.

[0124] (Appendix 5) The MN configured gap information includes a measurement gap identifier for each of the plurality of measurement gap patterns. A base station (200) according to any one of Supplementary Notes 1 to 4.

[0125] (Appendix 6) When a measurement gap identifier space that can be allocated by the MN (200M) is provided independently of the measurement gap identifier space that can be allocated by the SN (200S), the control unit (230) allocates the measurement gap identifier from the measurement gap identifier space that can be allocated by the MN (200M). 6. The base station (200) according to claim 5.

[0126] (Appendix 7) The network communication unit (220) receives SN setting gap information indicating each setting of one or more measurement gap patterns set by the SN (200S) to the UE (100) from the SN (200S) via the network interface. A base station (200) according to any one of Supplementary Notes 1 to 6.

[0127] (Appendix 8) A base station (200) that operates as a master node (MN) (200M) and a secondary node (SN) (200S) when using dual connectivity in which the SN (200S) communicates with a user equipment (UE) (100), a network communication unit (220) that receives, via a network interface, MN-configured gap information from the MN (200M) indicating each of a plurality of measurement gap patterns that the MN (200M) has configured in the UE (100); and a control unit (230) that determines at least one measurement gap pattern that the SN (200S) sets to the UE (100) based on the MN setting gap information. Base station (200).

[0128] (Appendix 9) The network communication unit (220) receives the measurement configuration transmitted from the MN (200M) to the UE (100) as the MN configuration gap information from the MN (200M). 9. The base station (200) according to claim 8.

[0129] (Appendix 10) The network communication unit (220) receives, from the MN (200M), information on part of the measurement configuration transmitted from the MN (200M) to the UE (100), which is configuration information individual to each of the plurality of measurement gap patterns, as the MN configuration gap information. 10. The base station (200) according to claim 9.

[0130] (Appendix 11) The MN-configured gap information includes measurement gap identifiers of the plurality of measurement gap patterns configured in the UE (100) by the MN (200M). A base station (200) according to any one of Supplementary Notes 8 to 10.

[0131] (Appendix 12) A transmitter (211) is further provided which transmits a radio resource control (RRC) message including information for setting the determined measurement gap pattern to the UE (100), When the SN (200S) configures the UE (100) with a measurement gap pattern selected from the plurality of measurement gap patterns configured in the UE (100) by the MN (200M), the transmitting unit (211) transmits the RRC message including the measurement gap identifier of the selected measurement gap pattern. 12. The base station (200) according to claim 11.

[0132] (Appendix 13) When a measurement gap identifier space that can be assigned by the SN (200S) is provided independently of the measurement gap identifier space that can be assigned by the MN (200M), the control unit (230) assigns the measurement gap identifier from the measurement gap identifier space that can be assigned by the SN (200S). 13. The base station (200) according to claim 11 or 12.

[0133] (Appendix 14) The network communication unit (220) transmits SN setting gap information indicating the setting of one or more measurement gap patterns set by the SN (200S) to the UE (100) to the MN (200M) via the network interface. A base station (200) according to any one of Supplementary Notes 8 to 13.

[0134] (Appendix 15) A communication method for a base station (200) operating as a master node (MN) (200M) and a secondary node (SN) (200S) when using dual connectivity to communicate with a user equipment (UE) (100), comprising: configuring a plurality of measurement gap patterns for the UE (100); and transmitting MN configuration gap information indicating the configuration of each of the plurality of measurement gap patterns to the SN (200S) via a network interface. Communication method.

[0135] (Appendix 16) A communication method for a base station (200) operating as a master node (MN) (200M) and a secondary node (SN) (200S) when using dual connectivity in which the SN (200S) communicates with a user equipment (UE) (100), comprising: receiving MN-configured gap information indicating each of a plurality of measurement gap patterns configured in the UE (100) by the MN (200M) from the MN (200M) via a network interface; and determining at least one measurement gap pattern that the SN (200S) sets to the UE (100) based on the MN setting gap information. Communication method.

Claims

1. A base station (200) operating as a master node (MN) (200M) connected to a communication device (100) and a secondary node (SN) (200S), a transmitter (211) configured to transmit to the communication device a radio resource control (RRC) message including first information used to configure each of a plurality of measurement gap patterns, the first information including information indicating a length of the measurement gap and information indicating a repetition period of the measurement gap, and second information used to configure an identifier of the measurement gap; a control unit (230) that includes, in a CG-ConfigInfo message, the first information indicating each of the plurality of measurement gap patterns configured in the communication device and the second information indicating an identifier of the measurement gap configured in the communication device; a network communication unit (220) that transmits an SN addition request message including the CG-ConfigInfo message to the SN. Base station.

2. The network communication unit transmits an SN modification request message including the CG-ConfigInfo message to the SN. The base station of claim 1 .

3. Each of the plurality of measurement gap patterns is set for a specific purpose. The base station according to claim 1 or 2.

4. A communication device (100) that communicates with a base station (200) that operates as a master node (MN) (200M) connected to a secondary node (SN) (200S), a receiver (112) configured to receive from the base station a radio resource control (RRC) message, the radio resource control (RRC) message including first information used to configure each of a plurality of measurement gap patterns and including information indicating a length of the measurement gap and information indicating a repetition period of the measurement gap, and second information used to configure an identifier of the measurement gap; a control unit (120) that performs measurements in the measurement gap based on the first information and the second information; The first information indicating each of the plurality of gap patterns set in the communication device and the second information indicating an identifier of the measurement gap set in the communication device are included in a CG-ConfigInfo message and are transmitted from the base station to the SN using an SN addition request message. Communication equipment.

5. The first information indicating each of the plurality of measurement gap patterns set in the communication device and the second information indicating an identifier of the measurement gap set in the communication device are included in the CG-ConfigInfo message and are transmitted from the base station to the SN using an SN modification request message. The communication device according to claim 4.

6. Each of the plurality of measurement gap patterns is set for a specific purpose.

6. The communication device according to claim 4 or 5.

7. A communication method for a base station (200) operating as a master node (MN) (200M) connected to a communication device (100) and a secondary node (SN) (200S), comprising: transmitting to the communication device a Radio Resource Control (RRC) message including first information used to configure each of a plurality of measurement gap patterns, the first information including information indicating a length of the measurement gap and information indicating a repetition period of the measurement gap, and second information used to configure an identifier of the measurement gap; including the first information indicating each of the plurality of measurement gap patterns configured in the communication device and the second information indicating an identifier of the measurement gap configured in the communication device in a CG-ConfigInfo message; sending an SN Add Request message including the CG-ConfigInfo message to the SN. Communication method.

8. The method of claim 7, further comprising the step of: sending an SN modification request message including the CG-ConfigInfo message to the SN. The communication method according to claim 7.

9. Each of the plurality of measurement gap patterns is set for a specific purpose.

9. The communication method according to claim 7 or 8.

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