Abstract: A radio terminal includes a receiver configured to receive a counting request, the counting request requesting transmission of a counting response from a plurality of radio terminals that are receiving a specific MBMS service or interested in the reception of the specific MBMS service, and a common resource setting from a network, the common resource setting indicating a common resource pool to be commonly used by the plurality of radio terminals for the transmission of the counting response; a controller configured to determine whether or not the radio terminal is receiving the specific MBMS service or interested in the reception thereof in response to receiving the counting request; and a transmitter configured to transmit the counting response to the network by using a radio resource included in the common resource pool in response to the determination that the radio terminal is receiving the specific MBMS service or interested in the reception thereof.

Abstract: A user equipment receives an MBMS service provided using SC-PTM transmission. The user equipment performs a cell reselection operation of selecting a cell to be used as a serving cell of the user equipment while the user equipment is in an RRC idle mode. In the cell reselection operation, the user equipment selects, as the serving cell, a cell having a highest ranking determined based on a radio quality and an offset from among a plurality of cells. In the cell reselection operation, when the user equipment is in an enhanced coverage, the user equipment uses an infinite offset as the offset to be applied to a cell where the MBMS service is provided by the SC-PTM transmission, in response to a predetermined condition for the SC-PTM transmission being satisfied, when the user equipment goes out of the enhanced coverage, stop using the infinite offset.

Abstract: A user equipment, apparatus and method comprise starting reception from a base station from a second slot out of a first slot and the second slot which configure a subframe, determining a first modulation order used for downlink control information transmitted in the second slot, and starting the reception from the second slot by using the first modulation order. The downlink control information is a PDCCH or an EPDCCH.

Abstract: A radio terminal according to one embodiment is used in a mobile communication system supporting uplink transmission using an unlicensed spectrum. The user terminal comprises a controller configured to perform LBT (Listen-Before-Talk) before the uplink transmission. The controller applies a first LBT scheme to the LBT, in response to reception of information indicating the first LBT scheme from a base station. The controller applies a second LBT scheme to the LBT, in response to reception of information indicating the second LBT scheme with a shorter LBT time interval than the first LBT scheme, from the base station.

Abstract: A first radio terminal transmits and receives a radio signal by using a limited frequency band limited to a bandwidth of a predetermined number of resource blocks. A second radio terminal transmits and receives a radio signal by using a frequency band wider than the limited frequency band. A base station transmits configuration information of SC-MTCH by SC-MCCH. The base station sets a first period to the first radio terminal and sets a second period shorter than the first period to the second radio terminal as an SC-MCCH change period in which the configuration information of the SC-MTCH can be changed. The base station receives an MBMS interest indication from the first radio terminal, the first radio terminal being in a connected mode, and determines whether or not to shift the first radio terminal to an idle mode based on the MBMS interest indication.

Abstract: A communication control method comprises a step S1 of transmitting, by a eNB 200, a paging message to a UE 100 by using a first frequency channel included in a plurality of frequency channels, a step S2 of receiving, by the UE 100, the paging message, a step S3 of selecting, by the UE 100, a second frequency channel included in the plurality of frequency channels, and a step S4 of transmitting, by the UE 100, a random access signal for establishing connection with the eNB 200 by using the second frequency channel. The paging message includes channel identification information used for selecting the second frequency channel. In the step S3, the UE 100 is configured to select the second frequency channel based on the channel identification information included in the paging message.

Abstract: A user equipment, method and apparatus receive a PDSCH from a base station and determine a modulation order used in the PDSCH based on whether the PDSCH is transmitted in a second slot out of a first slot and the second slot which configure a subframe.

Abstract: A base station according to an embodiment includes a controller configured to perform a process of transmitting, in a specific frequency band shared by a plurality of operators and/or a plurality of communication systems, a burst signal including data or a control signal and a discovery reference signal including a reference signal and/or a synchronization signal. If there is a transmission duration of the discovery signal within a transmission duration of the burst signal after starting the transmission of the burst signal, the controller performs a process of transmitting the discovery reference signal even within the transmission duration of the burst signal.

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 radio terminal according to one embodiment comprises: a controller configured to perform a process of: receiving, if the radio terminal is in a specific state different from an RRC connected state, multicast/broadcast data transmitted from a base station; and transmitting feedback information on the multicast/broadcast data to the base station. The controller is configured to autonomously determine a transmission parameter to be used for transmitting the feedback information and transmits the feedback information by using the determined transmission parameter.

Abstract: A radio terminal according to one embodiment comprises a controller configured to receive first control information for receiving, by the radio terminal, a special downlink control channel. The special downlink control channel carries control information to the radio terminal from a first cell with no connection for transmitting and receiving user data being established. The controller directly receives second control information for reducing an uplink interference in the first cell, on the special downlink control channel, from the first cell.

Abstract: A radio terminal according to one embodiment comprises a controller configured to perform radio communication in a time division duplex system, with a base station. The controller is configured to receive a downlink radio signal from the base station; and transmit to the base station, response information indicating whether reception of the downlink radio signal is successful, wherein the response information is transmitted by using an uplink radio resource different from an uplink control channel resource even if the uplink radio resource is not allocated for data transmission from the base station.

Abstract: A user equipment, an apparatus for controlling user equipment, and a method receive measurement configuration information from a first cell, the measurement configuration information indicating a subcarrier spacing applied to a second cell, and perform measurement on the second cell based on the measurement configuration information.

Abstract: A base station according to one embodiment comprises a controller configured to perform a downlink transmission process using a subframe. The subframe comprises a main PDCCH (Physical Downlink Control Channel) region located at a head portion of the subframe, and a data region other than the main PDCCH region. The data region comprises a short TTI region to which a short TTI (Transmission Time Interval) having a shorter time length than the subframe is applied. The short TTI region comprises a sub-PDCCH region. The controller is configured to arrange information indicating the sub-PDCCH region in the main PDCCH region.

Abstract: A communication method according to an embodiment comprises: notifying, by a base station, a radio terminal of a discontinuous reception (DRX) cycle; notifying, by a Mobility Management Entity (MME), the radio terminal of an extended DRX cycle longer than the DRX cycle; determining, by the radio terminal, whether or not the base station supports an extend DRX; using, by the radio terminal, the extended DRX cycle to execute an extended DRX operation in an idle mode, in response to determining that the base station supports the extend DRX; and using, by the radio terminal, the DRX cycle to execute a DRX operation without using the extended DRX cycle, in response to determining that the base station does not support the extend DRX.

Abstract: A base station according to one embodiment includes: a transmitter configured to transmit a synchronization signal in a cell using a predetermined subcarrier spacing, the cell being managed by the base station; and a controller configured to arrange, based on the predetermined subcarrier spacing, the synchronization signal in a plurality of discrete subcarriers not continuous in a frequency direction.

Abstract: A relay node according to one embodiment comprises a controller configured to establish a connection with a radio terminal and to establish a connection with a base station; a receiver configured to receive information of the radio terminal from the base station; and a transmitter configured to transmit the information to the radio terminal. The receiver receives delivery acknowledgement information from the radio terminal before the information is transmitted. The delivery acknowledgement information indicates that the radio terminal has received the information. The transmitter stops transmitting the information to the radio terminal in response to reception of the delivery acknowledgement information.

Abstract: A base station (200) according to an embodiment performs radio communication with a radio terminal (100). The base station transmits a reference signal to the radio terminal with a specific polarized wave, receives, from the radio terminal, polarized wave adjustment information generated by using the reference signal, adjusts a polarized wave based on the specific polarized wave by using the polarized wave adjustment information, and transmits an information signal to the radio terminal with the adjusted polarized wave.

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 radio communication system comprises: a first area entity operated in a first operation scheme in which use of a specific frequency band is permitted; and a second area entity operated in a second operation scheme in which use of the specific frequency band is permitted. A user terminal existing in an area of the first area entity notifies the first area entity of a frequency band change request for requesting a change of a frequency band used by the first area entity when a frequency of the specific frequency band used by the first area entity is congested due to use by the second area entity. The first area entity changes a frequency band used by the first area entity in response to the frequency band change request.