Abstract: A user device comprises a communication unit configured to perform communication to which dual connectivity is applied, wherein a master cell group and a secondary cell group are configured in the dual connectivity, a control unit configured to detect occurrence of a failure in the master cell group, and a transmission unit configured to transmit information related to the occurrence of the failure in the master cell group to a master node of the master cell group, wherein the control unit changes a primary cell to another cell by performing handover to a different RAT (Radio Access Technology).

Abstract: A user apparatus includes a transmission unit for transmitting a signal related to a random access procedure in a serving cell; a reception unit for receiving a signal related to the random access procedure in the serving cell; and a control unit for determining a carrier to be used for the random access procedure, the carrier being configured to the serving cell. The control unit determines whether a first carrier is configured to the serving cell, determines whether the first carrier of the serving cell is supported when the first carrier is configured to the serving cell, and determines to use the first carrier for the random access procedure when the first carrier of the serving cell is supported. An operation of determining the carrier to be used for the random access procedure is performed in at least one of a MAC layer and an RRC layer.

Abstract: A terminal includes a receiver that receives an instruction signal indicating to modify a configuration of a radio link monitoring; and a controller that modifies a parameter used for the configuration of the radio link monitoring in accordance with the instruction signal received by the receiver.

Abstract: User equipment includes a transmitter configured to transmit a random access preamble or an identifier of the user equipment to a base station apparatus in a two-step random access procedure, a receiver configured to receive a response signal corresponding to at least one of the random access preamble and the identifier of the user equipment, and a downlink signal based on the response signal, from the base station apparatus, and a control unit configured to determine that a contention resolution is successful when information included in the downlink signal matches a part of or all of the identifier of the user equipment.

Abstract: A user equipment includes a receiving unit configured to receive system information from a cell, a control unit configured to determine, based on an information element and identifiers, whether or not the cell is a candidate to be selected, the information element indicating other uses included in the system information and identifiers being of a plurality of closed access groups (CAGs) identifying groups of subscribers who are allowed to access the cell, and a communication unit configured to perform access to the cell in a case in which the control unit determines that the cell is the candidate to be selected.

Abstract: A terminal (200) configures PCell and SCell simultaneously. The terminal (200) includes a receiving unit (220) that receives a reference signal for use in a detection of a beam failure in the SCell, and a controller (270) that performs a beam failure recovery procedure based on a reception quality of the reference signal. The SCell belongs to a predetermined group regarding the BFR procedure. The controller (270) performs the BFR procedure in a predetermined cell within the predetermined group.

Abstract: An SN (100C) includes a transmitting unit (110b) that transmits, to an MN (100A) to which a terminal (200) is connected, a first message including configuration information of a cell formed by the SN (100C), and a control unit (140b) that determines to delete the configuration information of the cell according to a state of the cell. The transmitting unit (110b) transmits, to the MN (100A), a second message instructing deletion of the configuration information of the cell.

Abstract: A terminal is disclosed including a transmitting unit that transmits a request signal for requesting a radio base station to transmit a reference time, to the radio base station; and a receiving unit that receives a radio resource control message from the radio base station according to the transmission of the request signal, the radio resource control message including a reference system frame number and the reference time associated with the reference system frame number. In other aspects, radio base stations, a radio communication method, and a radio communication system are also disclosed.

Abstract: A user device includes a receiving unit configured to receive first information and second information from a base station device, the first information indicating one or more bands that are candidates for a band combination to be supported, the second information indicating which RAT (Radio Access Technology) is to be used; a control unit configured to determine, based on the second information, the band combination to be supported from among the one or more bands included in the first information; and a transmitting unit configured to transmit, to the base station device, is terminal capability information including the determined band combination.

Abstract: A user equipment includes a receiving unit configured to receive, from a base station apparatus, information for requesting a report of a User Equipment (UE) capability, a control unit configured to generate the report including a supported UE capability, and a transmitting unit configured to, in a case where an Access Stratum (AS) security with the base station apparatus is activated, transmit the report to the base station apparatus.

Abstract: UE (200) executes dual connectivity in which it simultaneously connects to a radio base station and other radio base station. The UE (200) includes a transmitting unit (210) that transmits to the radio base station and the other radio base station uplink transmission related information indicating an uplink transmission state, and a control unit (230) that controls transmission or stop of transmission of the uplink transmission related information of a predetermined type.

Abstract: A network node that is a second network node connected to a user device and a first network node includes: a control unit that acquires information regarding a layer which is terminated at the user device and the second network node; and a transmission unit that transmits the information regarding the layer to the first network node. The layer is not terminated at the user device and the first network node.

Abstract: An user equipment in a wireless communication system including a base station and the user equipment is configured to include: a reception unit configured to receive information for setting a value of a predetermined timer from the base station; and a transmission unit configured to transmit an uplink data in a case where the predetermined timer is not activated, wherein the transmission unit activates the predetermined timer in a case where that the value of the predetermined timer is set from the base station and information indicating that there is no uplink data to be transmitted is transmitted to the base station.

Abstract: A user apparatus includes a communication unit configured to communicate with a first base station apparatus and a second base station apparatus, wherein the first base station apparatus is a master node in a New Radio (NR) radio communication system and the second base station apparatus is a secondary node in the NR radio communication system; a reception unit configured to receive from the first base station apparatus an instruction to measure a system frame number and frame timing difference (SFTD) representing a system frame number and frame timing difference between cells; a control unit configured to measure SFTD between a cell of the first base station apparatus and a cell of the second base station apparatus based on the instruction to measure SFTD; and a transmission unit configured to transmit to the first base station apparatus a measurement result including the measured SFTD.

Abstract: A terminal (200) configures PCell and SCell simultaneously. The terminal (200) includes a receiving unit (220) that receives a reference signal for use in a detection of a beam failure in the SCell, and a controller (270) that performs at least one of the detection of the beam failure and a beam failure recovery request based on a reception quality of the reference signal. The controller (270) performs at least one of the detection of the beam failure and the beam failure recovery request when a predetermined condition is satisfied.

Abstract: A terminal includes a receiver configured to receive a Timing Advance command; and a controller configured to control a timer related to uplink time alignment, wherein, in response to receiving the Timing Advance command by the receiver, the controller starts the timer, and wherein, upon receiving, by the receiver, a contention resolution message, the controller stops the timer after a time period from the reception of the contention resolution message.

Abstract: A UE (200) performs a random access procedure with a gNB (100). The UE (200) transmits to a network via a radio base station at least one of a synchronization signal block used for performing the random access procedure, a reception quality in the synchronization signal block, a group of random access preambles, and number of times for which power ramping was performed in the random access procedure.

Abstract: In a radio communication system, a split bearer that passes from a core network to a secondary cell group and branches from gNB 100B included in the secondary cell group to eNB 100A included in a master cell group is set, and data is transmitted to a user equipment via thus set split bearer. The gNB 100B transmits, to the eNB 100A, Use of SCG Radio Resource that indicates whether to configure a split bearer that uses a radio resource between the user equipment and the gNB 100B. The eNB 100A sets the split bearer based on the received Use of SCG Radio Resource.

Abstract: In one aspect of the present invention, a first base station for communicating with user equipment together with a second base station according to dual connectivity includes a data storage unit configured to store data to be transmitted from the first base station to the user equipment; a reception unit configured to receive from the second base station information indicating whether data to be transmitted from the second base station to the user equipment exist; and a state control unit configured to, when information indicating that data to be transmitted from the second base station to the user equipment exist is received, prevent the user equipment from releasing a radio resource or transitioning to a discontinuous reception state, even if the amount of to-be-transmitted data stored in the data storage unit is less than or equal to a predetermined threshold.

Abstract: A user equipment is disclosed that includes a transmission and reception unit configured to communicate with a master base station and a secondary base station simultaneously in dual connectivity. The user equipment includes a Radio Link Control (RLC) layer processing unit configured to have an RLC layer for the master base station and an RLC layer for the secondary base station and a Packet Data Convergence Protocol (PDCP) layer processing unit configured to have a PDCP layer transmitting and receiving data to/from the RLC layer for the master base station and the RLC layer for the secondary base station. When a split bearer configured for the secondary base station is deleted, the RLC layer processing unit performs re-establishment on the RLC layer for the secondary base station and releases the split bearer after execution of the re-establishment.