Abstract: A user terminal is disclosed for use in a radio communication system to employ Listen Before Talk (LBT) such that the user terminal includes a measurement section that makes a measurement for a specific frequency carrier, based on measurement timing configuration information that relates to the specific frequency carrier and that is transmitted from a radio base station, and a transmission section that transmits the measurement result to the radio base station, and therefore, the user terminal improves spectral efficiency in communication using unlicensed carriers.

Abstract: User equipment of a mobile communication system supporting a function for establishing a connection by reusing context information retained in each of the user equipment and a base station includes a transmitter that transmits, to the base station, first identifying information for identifying a retaining base station that retains base station side context information for the user equipment and second identifying information for identifying the base station side context information when the user equipment retains user equipment side context information; and a connector that establishes the connection with the base station by using the user equipment side context information after the base station obtains the base station side context information from the retaining base station.

Abstract: To provide a radio communication device and a radio communication method that can surely avoid a state that communication cannot be started because of a disagreement in states in an intermediate layer, which is lower to RRC layer, when transitioning between a connected state (RRC-Connected) and a suspended state (RRC-Suspended) in the RRC layer. UE (100) includes a state controlling unit (120) that controls the RRC layer to be in the connected state or the suspended state, and an interruption processing unit (130) that initializes at least a part of states in the intermediate layer, specifically MAC layer/RLC layer/PDCP layer, after the RRC layer has transitioned from the connected state to the suspended state. The state controlling unit (120) causes the RRC layer to resume from the suspended state to the connected state based on the state of the intermediate layer initialized by the interruption processing unit (130).

Abstract: A base station in a mobile communication system that supports a function to reuse context information retained in each of a user apparatus and the base station to establish a connection is disclosed including a deletion unit configured to delete predetermined information in the context information associated with the user apparatus when the user apparatus ends a connected state in a condition where the base station retains the context information associated with the user apparatus, and an acquisition unit configured to acquire the predetermined information from a communication control apparatus that retains the predetermined information in the mobile communication system when the user apparatus restarts the connected state.

Abstract: In dual connectivity or inter-base station carrier aggregation, synchronization between base stations is achieved while preventing processing load from increasing in user equipment. A method of acquiring broadcast information when configuring or performing inter-base station carrier aggregation in a mobile communication system including a first base station, a second base station, and a mobile device connected to the first base station, includes the steps of, at the first base station, creating first broadcast information about the second base station, except for information as to synchronization between base stations and supplying the first broadcast information to the mobile device on a dedicated radio resource control signal; and at the mobile device, after receiving the dedicated radio resource control signal, receiving the information as to synchronization between base stations over a physical broadcast channel of a first cell of the second base station based upon the first broadcast information.

Abstract: There is provided user equipment for communicating with a base station in a mobile communication system including the base station and the user equipment, the user equipment including a PDCP layer processor provided with a storage unit that receives and stores a plurality of acknowledgement signals to be transmitted to the base station; and an RLC layer processor that transmits, to the PDCP layer processor, a signal transmission grant signal that indicates that transmission of an uplink signal is allowed, wherein, upon receiving the signal transmission grant signal, the PDCP layer processor transmits, to the RLC layer processor, an acknowledgement signal that is received most recently among the plurality of acknowledgement signals.

Abstract: A mobile communication method according to the present invention includes the steps: transmitting, from an exchange (MME) to a first radio base station (eNB), a location information reporting instruction which provides an instruction to report location information on a mobile station (UE); reporting, the first radio base station (eNB) to the exchange (MME), the location information on the mobile station (UE), in accordance with the location information reporting instruction; transmitting, the location information reporting instruction to a second radio base station (eNB), in a handover procedure of the mobile station (UE) from the first radio base station (eNB) to the second radio base station (eNB); and reporting, from the second radio base station (eNB) to the exchange (MME), the location information on the mobile station (UE), in accordance with the location information reporting instruction.

Abstract: A radio communication device that avoids the trouble arising because of transmission and reception of a signal repeatedly several times, and performs communication appropriately with a radio base station is provided.

Abstract: A paging control method in a mobile communication system including a base station and a communication control apparatus, including: an instruction step in which, in a state where a connection between the base station and the communication control apparatus is established, the base station transmits a connection maintaining instruction signal to the communication control apparatus; and a paging step in which, when the communication control apparatus that receives the connection maintaining instruction signal receives downlink data for the user apparatus, the communication control apparatus holds the downlink data in a buffer and transmits a paging signal for the user apparatus while maintaining the connection between the base station and the communication control apparatus.

Abstract: An object is to provide a user device, a radio base station, and a radio communication method that are capable of extending a predetermined number of spare bits included in notification information such as MIB to be utilized for a plurality of purposes. The user device determines contents of the notification information. The notification information includes a frame (310) having a plurality of slots (410) and a frame (320) having a plurality of slots (420) to each of which system information of a same type is assigned. The system information includes spare bits (500) of 10 bits. The spare bits assigned to the slot (410) are used for a first purpose, and the spare bits assigned to the slot (420) are used for a second purpose that is different from the first purpose.

Abstract: An object is to provide a user device and a radio communication method that are capable of appropriately detecting radio link failure (RLF) even when an enhanced coverage mode is in operation. UE (200) includes CE level setting unit (230) that sets, when the UE is set in the enhanced coverage mode, a reception quality threshold (Qin/Qout) of a reference reception power level (RSRP/RSRQ) specified for CE level, and a radio link monitoring unit (240) that executes radio link monitoring based on the set reception quality threshold. The CE level setting unit (230) sets, regardless of whether the UE (200) is set to any CE level or not, a reception quality threshold specified for the maximum CE level.

Abstract: Provided is a user equipment in a mobile communication system that supports a function of performing connection establishment reusing context information retained in each of the user equipment and a base station, including: a receiving unit that receives instruction information indicating whether or not the base station has a function of performing RRC connection reusing retained context from the base station; a determining unit that determines whether or not the base station has the function on the basis of the instruction information received through the receiving unit; and a transmitting unit that transmits a message including context retention information indicating that the user equipment retains user equipment side context information to the base station when the determining unit determines that the base station has the function.

Abstract: A user apparatus according to an embodiment is provided. The user apparatus communicates with a base station, and includes a determination unit configured to, in the case of making a VoLTE call, determine whether a predetermined indicator is included in broadcast information received from the base station; and a transmission unit configured to transmit to the base station an RRC connection request message in which information is included indicating a request for an RRC connection to be established for making a VoLTE call.

Abstract: User equipment communicating with a base station of a wireless communication system including the base station and the user equipment includes a selection unit configured to select a random access signal group from a plurality of random access signal groups by comparing a size of a message transmitted through a predetermined logical channel with a predetermined threshold value and select a random access signal from the random access signal group; and a transmission unit configured to transmit the random access signal selected by the selection unit to the base station, wherein the transmission unit transmits the message through the predetermined logical channel using a resource allocated according to a response from the base station with respect to the random access signal.

Abstract: A base station of a radio communication system supporting carrier aggregation is provided. The base station includes a receiver configured to receive, from a user apparatus, first band combination information that indicates combinations of bands supported by the user apparatus through the carrier aggregation, the first band combination information being generated in a first format; a generator configured to generate, based on the combinations of bands indicated by the first band combination information, second band combination information using a second format; and a transmitter configured to transmit, to another base station or a switching apparatus, the second band combination information generated by the generation unit.

Abstract: Provided is user equipment of a mobile communication system that supports a function for establishing a connection by reusing context information retained in each of the user equipment and a base station, the user equipment including a transmitter that transmits, to the base station, a first message indicating that the user equipment retains user equipment side context information; a receiver that receives, from the base station, a second message indicating that the base station retains base station side context information associated with the user equipment; and a connecting unit that establishes a connection with the base station using the user equipment side context information after receiving the second message.

Abstract: In a handover procedure between cells under different radio base stations (eNB), “RRC diversity” is implemented while considering conditions in a PDCP layer and an RLC layer. A handover method of the invention includes the steps of: causing a radio base station (eNB #1) to transmit to a radio base station (eNB #10), information necessary for generating PDCP-PDU and RLC-PDU; causing the radio base station (eNB #10) to transmit to the radio base station (eNB), “HO ack” including “HO command”; and causing each of the radio base station (eNB #1) and the radio base station (eNB #10) to generate the RLC-PDU including the PDCP-PDU containing the “HO command” based on the information and to transmit the RLC-PDU to a mobile station (UE).

Abstract: A communication apparatus including a function configured to perform data transmission by multicasting to a plurality of apparatuses by radio communication, including: a request reception unit configured to receive a join request from an apparatus that desires multicast data reception from the communication apparatus; a match control unit configured to perform control for matching values of a state variable of layer 2 in the radio communication between the communication apparatus and the apparatus that transmits the join request in response to receiving the join request by the request reception unit.

Abstract: A user apparatus in a mobile communication system including a first base station that sets a link of a control plane between the first base station and the user apparatus, and a second base station that sets a link of a user plane between the second base station and the user apparatus, including: radio link monitoring means configured to perform monitoring of a radio link; and connection control means configured, when disconnection of the link of the control plane is detected by the radio link monitoring means, to perform reestablishment of the link of the control plane for the user apparatus while maintaining the link of the user plane.

Abstract: A base station in a mobile communication system, including: data communication amount measurement means configured to measure a data communication amount of a user apparatus connected to the base station for each bearer in the user apparatus for each carrier for transmitting data of the bearer; and data communication amount report control means configured to receive a data communication amount report request message from a data communication amount management apparatus in the mobile communication system, generate a data communication amount report message including a data communication amount corresponding to a request in the data communication amount report request message, and transmit the data communication amount report message to the data communication amount management apparatus.