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.

Abstract: A radio terminal according to an embodiment is a terminal to which radio resources are allocated from a base station by Semi-Persistent Scheduling (SPS). The radio terminal includes a controller configured to perform processing of transmitting, to the base station, an explicit SPS release notice for releasing the radio resources allocated by the SPS.

Abstract: A base station according to a first feature is used in a mobile communication system in which a plurality of functions related to radio communication are specified. The base station includes a receiver that receives processor information related to a load state or an attribute of an processor included in a radio terminal from the radio terminal, a controller that selects at least one function to be executed by the radio terminal on the basis of the processor information, and a transmitter that transmits information indicating the selected function to the radio terminal.

Abstract: A radio terminal that transmits uplink data to a base station using a PUSCH resource includes a controller configured to execute a process of transmitting a scheduling request for requesting allocation of the PUSCH resource to the base station using a PUCCH resource. The scheduling request includes buffer information indicating an amount of the uplink data in a transmission buffer of the radio terminal.

Abstract: A user terminal according to an embodiment transmits uplink data to a base station using an unlicensed band. The user terminal includes a controller configured to, if uplink data transmission is started from a middle of a subframe according to a monitoring result of the unlicensed band, perform processing of transmitting a specific signal being different from the uplink data, at a beginning of the uplink data.

Abstract: A user equipment for a mobile communication system, and method and chip thereof, receives a first parameter and a second parameter broadcasted from the current serving cell, and reselects a target cell to be used as a serving cell from among plural cells operated at different frequencies. The first parameter defines a probability for performing reselection of the target cell, and the second parameter is a timer value to be set in a timer started at a timing at which a quality measurement for neighbor cells ends. Reselecting includes, after receiving the first and second parameter, periodically measuring qualities of neighbor cells at timer defined timings, comparing a value corresponding to IMSI of the user equipment with a value corresponding to the first parameter, and reselecting the target cell from among cells having a quality satisfying predetermined quality criteria, based on results of the quality measurement and the comparison.

Abstract: A UE configured to transmit, to an eNB 200, scheduling requests for requesting a PUSCH resource, by using a PUCCH resource, transmits, among the scheduling requests, a second scheduling request different from a first scheduling request. As the PUCCH resource for the transmission of the second scheduling request, a periodic PUCCH resource is configured. As the PUCCH resource for the transmission of the second scheduling request, an aperiodic PUCCH resource is configured.

Abstract: A user terminal according to a first feature is used in a mobile communication system. The use terminal includes: a receiver configured to receive a measurement instruction to instruct measurement in an unlicensed band, from a base station; a controller configured to, in response to reception of the measurement instruction, search for a radio signal transmitted in a frequency channel included in the unlicensed band, and measure reception power of the radio signal detected by the search, even when a cell identifier of a measurement target cell is not designated in the measurement instruction; and a transmitter configured to transmit a measurement report including an identifier of a transmission source of the detected radio signal and a measurement result of the reception power, to the base station.

Abstract: In a communication control method according to one embodiment, a first radio terminal executes, control to establish a predetermined connection through a second radio terminal that is a relay terminal. The predetermined connection is used for transmitting control information related to the first radio terminal between the first radio terminal and a base station. The first radio terminal starts control to establish the predetermined connection, in response to receiving authorization information indicating that establishing the predetermined connection is possible.

Abstract: In a user equipment, base station and method for a mobile communication system, the user equipment receives, from a first base station, transmission power control information used for a dual simultaneous transmission in which radio signals are simultaneously transmitted to both the first base station and a second base station, and determines a first transmission power and a second transmission power for the dual simultaneous transmission based on the transmission power control information. The first transmission power is used for transmitting a radio signal to the first base station, and the second transmission power is used for transmitting a radio signal to the second base station.

Abstract: A communication system, first communication terminal, processor and base station that supports direct communication between terminals comprises a terminal that autonomously selects radio resources to be used in the direct communication, from among the candidate radio resources based on information received from the base station, performs the direct communication by use of the selected radio resources, and detects interference power after receiving the information indicating the candidate radio resources. The terminal transmits information on interference in the candidate radio resources to the base station in response to value of the detected interference power being higher than a threshold value.

Abstract: A base station includes a controller that performs multicast service SC-PTM transmission, and a transmitter that transmits SC-PTM configuration information related to a configuration of the SC-PTM transmission via a SC-PTM control channel, which is a logical channel different from a MCCH, and transmits multicast data via a traffic channel for the SC-PTM transmission. Each of the SC-PTM control channel and the traffic channel is mapped on a DL-SCH. The transmitter transmits a SIB related to the SC-PTM control channel via a BCCH, transmits first resource allocation information for transmitting the SC-PTM configuration information via a PDCCH, where a predetermined RNTI for the SC-PTM control channel is applied to transmission of the first resource allocation information, and transmits second resource allocation information for transmitting multicast data by the SC-PTM transmission via the PDCCH.

Abstract: A base station performs radio communication with a radio terminal using at least one narrow frequency band where the number of resource blocks is limited to a predetermined resource block number. The base station comprises a transmitter configured to transmit, to the radio terminal, configuration information for frequency hopping where the radio communication is performed while switching the narrow frequency band; and a controller configured to allocate, to the radio terminal, a first frequency band of the frequency hopping and a frequency band of a hopping destination. The first frequency band and the frequency band of the hopping destination respectively include the narrow frequency band and fraction resource blocks. The fraction resource blocks are resource blocks, the number of which is smaller than the predetermined resource block number.

Abstract: A user terminal includes: a receiver configured to receive multicast/broadcast data transmitted from a base station to a plurality of user terminals using the same downlink radio resources; a controller configured to select uplink radio resources to be used for transmission of feedback information, from a resource pool allocated from the base station to a group including the plurality of user terminals; and a transmitter configured to transmit the feedback information to the base station using the selected uplink radio resources.

Abstract: A base station transmits, to a user terminal, a connection release request for requesting a release of an RRC connection. The connection release request includes information indicating a request of holding an identifier assigned by the base station, and the information causes the user terminal in an idle state to hold the identifier. The base station performs a random access procedure with the user terminal in the idle state. The random access procedure includes receiving a random access signal from the user terminal, transmitting a random access response that is a response to the random access signal, to the user terminal, and receiving a control signal together with the identifier from the user terminal after transmitting the random access response, while the user terminal is in the idle state.

Abstract: A communication control method comprises: receiving, by a user terminal, from a base station, first information indicating a Device to Device (D2D) frequency available in a D2D discovery procedure for discovering a proximal terminal; and using, by the user terminal, not only the frequency indicated by the first information, but also a frequency not indicated by the first information. The frequency not indicated by the first information is different from the frequency indicated by the first information and is indicated by second information received from another cell different from a cell in which the user terminal exists.

Abstract: In a mobile communication system, UE 100-1 that transmits a radio signal to a transmission target receives a plurality of TPC parameters from eNB 200 and control a transmission power of the radio signal, on the basis of the plurality of TPC parameters. The plurality of TPC parameters include: a first TPC parameter (TPC parameter A, B) applied to a single transmission in which one radio signal is singly transmitted; and a second TPC parameter (TPC parameter C) applied to a simultaneous transmission in which a plurality of radio signals (radio signal SG1, SG2) different in frequency are simultaneously transmitted to a plurality of transmission targets.

Abstract: A base station according to one embodiment provides multicast service by SC-PTM transmission. The base station includes a controller configured to perform processing of transmitting SC-PTM configuration information related to a configuration of the SC-PTM transmission via a GCCH (SC-PTM control channel) which is a logical channel different from a MCCH. The GCCH is mapped on the DL-SCH.

Abstract: A user terminal according to an embodiment includes a receiver that receives a list transmitted from a base station, the list including discovery resource configurations; and a controller that selects a discovery resource configuration from among the discovery resource configurations, and uses the selected discovery resource configuration to directly transmit a discovery signal to other user terminals. Each of the discovery resource configurations includes: time resource information indicating time resources used for transmitting a discovery signal and including a variable number substituted into a mathematical expression; frequency resource information indicating frequency resources used for transmitting the discovery signal and including a range of continuous resource block numbers; and power information indicating transmission power used for transmitting the discovery signal.

Abstract: A radio terminal according to an embodiment includes a controller configured to perform inter-frequency sidelink discovery transmission of transmitting a sidelink discovery signal at a frequency different from a frequency of a serving cell. The controller is further configured to receive, from the serving cell, a message including resource allocation information and frequency information. The resource allocation information is information indicating radio resources to be used for the inter-frequency sidelink discovery transmission. The frequency information is information indicating the different frequency to which the resource allocation information is applied.