Abstract: A user equipment, method used in a user equipment, and an apparatus for a user equipment include receiving from a first cell operated in a licensed band, configuration information configuring a second cell operated in an unlicensed band, performing a listen-before-talk (LBT) procedure on the second cell, counting a number of failures of the LBT procedure on the second cell, and transmitting information based on the number of failures of the LBT procedure on the second cell, to the first cell operated in the licensed band, the information indicating the failure of the LBT procedure on the second cell.

Abstract: User equipment, an apparatus configured to control user equipment, and a method. The method may include receiving by a user equipment from a base station, a synchronization signal and a master information block, the master information block transmitted at a same transmission cycle as a transmission cycle of the synchronization signal. The method may further include receiving by the user equipment from the base station, first information indicating time domain positions at which the synchronization signal and the master information block are to be transmitted. In addition, the method may include receiving by the user equipment from the base station, second information indicating a periodicity of transmission of the synchronization signal and the master information block. The periodicity indicated by the second information may be different from 40 ms.

Abstract: A user equipment, apparatus for controlling user equipment, and method performed by user equipment includes receiving a radio resource control (RRC) Release message from a base station included in a radio access network (RAN). The RRC Release message includes an indication causing the user equipment to transition from an RRC connected state to a specific state, the specific state being a state in which a RRC connection is suspended for the user equipment. The user equipment is caused to transition from the RRC connected state to the specific state in response to receiving the RRC Release message, perform a cell reselection operation when the user equipment is in the specific state, and perform, when the user equipment in the specific state, an operation of causing the user equipment to transition from the specific state to an RRC idle state in response to reselecting a cell not supporting the specific state.

Abstract: A mobile communication system according to one embodiment comprises: a base station configured to transmit discovery reference signal in an unlicensed spectrum, and a radio terminal configured to receive the discovery reference signal in the unlicensed spectrum. The base station notifies the radio terminal of timing information indicating a timing at which the discovery reference signal is to be transmitted in the unlicensed spectrum.

Abstract: A user equipment and apparatus receive from a base station, configuration information configuring the user equipment to provide assistance information indicating a preference of the user equipment to leave RRC connected state, and transmit to the base station, assistance information indicating that a preferred RRC state of the user equipment is an RRC state in which an RRC connection is suspended. A base station transmits to a user equipment, configuration information configuring the user equipment to provide assistance information indicating a preference of the user equipment to leave RRC connected state, and receives from the user equipment, assistance information indicating that a preferred RRC state of the user equipment is an RRC state in which an RRC connection is suspended.

Abstract: Configurations of a user equipment and an apparatus provided in a user equipment, and a method used in a user equipment, receive from a base station, for each bandwidth part of a plurality of bandwidth parts provided in a bandwidth of one carrier, information indicating a frequency location of the bandwidth part and information indicating a subcarrier spacing applied to the corresponding bandwidth part, receive from the base station, information indicating a use condition of a predetermined bandwidth part included in the plurality of bandwidth parts. In response to determining that the use condition is satisfied, the configurations and method use the predetermined bandwidth part.

Abstract: A user equipment, apparatus, and method receives from a base station, for each bandwidth part of a plurality of bandwidth parts provided in a bandwidth of one carrier, information indicating a frequency location of the bandwidth part and information indicating a subcarrier spacing applied to the corresponding bandwidth part, and receives, from the base station, broadcast information including information on a special bandwidth part which the user equipment should use initially. A base station transmits to a user equipment, for each bandwidth part of a plurality of bandwidth parts provided in a bandwidth of one carrier, information indicating a frequency location of the bandwidth part and information indicating a subcarrier spacing applied to the corresponding bandwidth part, and transmits to the user equipment, broadcast information including information on a special bandwidth part which the user equipment should use initially.

Abstract: A user equipment, method used in user equipment, and apparatus for controlling a user equipment operate to receiving a connected mode DRX parameter configured by a base station, and transmit to the base station a message including information indicating a connected mode DRX parameter preferred by the user equipment. The connected mode DRX parameter preferred by the user equipment includes at least one of DRX-InactivityTimer, DRX-ShortCycle, and DRX-ShortCycleTimer.

Abstract: A user equipment, method used in a user equipment, and an apparatus for a user equipment include receiving from a first cell operated in a licensed band, configuration information configuring a second cell operated in an unlicensed band, performing a listen-before-talk (LBT) procedure on the second cell, counting a number of failures of the LBT procedure on the second cell, and transmitting information based on the number of failures of the LBT procedure on the second cell, to the first cell operated in the licensed band, the information indicating the failure of the LBT procedure on the second cell.

Abstract: A radio terminal receives multicast data belonging to an MBMS service from a base station.

Abstract: User equipment, apparatus and method perform dual connectivity with a first base station acting as a master base station and a second base station acting as a secondary base station, transmit to the master base station capability information indicating that the user equipment supports a function of skipping a random access procedure, and receive from the master base station, a message instructing to change the secondary base station from the second base station to a third base station. The message includes information indicating that random access procedure for the third base station is skipped and an including an uplink grant indicating radio resources allocated by the third base station and a timing advance (TA) value to be applied to an uplink transmission to the third base station. The user equipment transmits the uplink transmission to the third base station by using the uplink radio resources indicated by the uplink grant.

Abstract: A user equipment, method, and chipset receive from a base station resource information indicating usable radio resources for data transmitted in the direct communication, detect a power when receiving a radio signal directly transmitted from another user terminal, and determine, based on the result of the process, a radio resource used to transmit the data from among the usable radio resources indicated by the resource information.

Abstract: A radio terminal according to one embodiment comprises: a controller configured to detect a radio problem in communication with a base station in an RRC connected state and attempt a recovery from the radio problem; and a transmitter configured to transmit, to the base station, a polling signal for confirming whether or not the base station considers an RRC state of the radio terminal as the RRC connected state in response to the successful recovery. The controller maintains the RRC connected state in response to reception, from the base station, of a response signal to the polling signal.

Abstract: A user terminal, method used in a user terminal, and an apparatus for a user terminal include receiving from a base station measurement configuration information configuring measurement of a frequency channel in an unlicensed band, measuring signal strength of radio signals transmitted in the frequency channel, determining occupancy situation of the frequency channel based on the measured signal strength and a threshold, and transmitting to the base station a measurement report including information indicating the occupancy situation of the frequency channel.

Abstract: A user equipment, method, and chipset receive system information block (SIB) broadcasted from a base station, and while the user equipment is in a radio resource control (RRC) idle mode in which no RRC connection is established between the use equipment and the base station, the SIB is used to control the D2D communication. Data is transmitted to other user equipment by the D2D communication based on the SIB while the user equipment is in the RRC idle mode. The SIB includes resource information indicating usable radio resources for the D2D communication and power information used for controlling transmission power in the D2D communication. The transmitting comprises determinations of radio resources used to transmit the data based on the resource information and transmission power used in transmitting the data based on the power information, and transmitting the data using the determined radio resources and the determined transmission power.

Abstract: A user equipment and apparatus receive from a base station, configuration information configuring the user equipment to provide assistance information indicating a preference of the user equipment to leave RRC connected state, and transmit to the base station, assistance information indicating that a preferred RRC state of the user equipment is an RRC state in which an RRC connection is suspended. A base station transmits to a user equipment, configuration information configuring the user equipment to provide assistance information indicating a preference of the user equipment to leave RRC connected state, and receives from the user equipment, assistance information indicating that a preferred RRC state of the user equipment is an RRC state in which an RRC connection is suspended.

Abstract: In a first user equipment, apparatus and method, a first user equipment performs sidelink communication with a second user equipment, receives a first message from the second user equipment, where the first message is periodically transmitted from the second user equipment based on a first timer, starts or restarts a second timer upon receiving the first message, where a value of the second timer is determined based on a value of the first timer, and transmits a second message to a network apparatus upon expiration of the second timer, where the second message indicates that the second user equipment is disconnected from the first user equipment.

Abstract: A base station (200) according to one embodiment uses a specific frequency band shared by a plurality of operators and/or a plurality of communication systems. The base transmit, to a radio terminal (100-1), interference-related information relating to interference detected by the base station in the specific frequency band.

Abstract: A radio terminal according to one embodiment is configured to perform a relay between another radio terminal and a network. The radio terminal comprises: a transmitter configured to notify the network of first information indicating that the radio terminal is a relay terminal of the another radio terminal; a controller configured to forward data addressed to the another radio terminal to the another radio terminal via a connection between the another radio terminal through the radio terminal and the network; and a receiver configured to receive from the network a message indicating that the data addressed to the another radio terminal exists when at least part of the connection is released. The controller is configured to start control for establishing the connection in order to forward the data addressed to the another radio terminal in response to receiving the message.

Abstract: A base station transmits, to another base station, a paging request that requests the another base station to page a user equipment, and receives, from the another base station, a message indicating that the paging has failed in the another base station for the user equipment. The another base station receives the paging request requesting the another base station to page a user equipment, and pages the user equipment based on the paging request received from the base station, and transmits to the base station a message indicating that the paging has failed in the another base station for the user equipment.