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 user terminal according to a first aspect is used in a mobile communication system. The user terminal comprises: a receiver configured to receive, from a base station, candidate timing information indicating candidate timings of an uplink transmission on an unlicensed band channel that is a frequency channel of an unlicensed band; a controller configured to determine, by monitoring the unlicensed band channel, a transmission timing at which the uplink transmission to the base station is performed, from the candidate timings indicated by the candidate timing information; and a transmitter configured to transmit, at the transmission timing, uplink data via the unlicensed band channel to the base station.

Abstract: A base station according to an embodiment is a base station included in a RAN of a mobile communication system. The base station includes a receiver configured to receive, from a radio terminal in a specific state, a message indicating that the radio terminal has left a RAN paging area, and a transmitter configured to transmit, to a mobility management entity, paging area information related to update of the RAN paging area in response to the reception of the message. The specific state is a state in which an anchor base station in the RAN paging area maintains an S1 connection for the radio terminal and the RAN paging area is configured to the radio terminal.

Abstract: A network apparatus according to an embodiment performs communication with a user terminal comprising a first communication unit configured to perform communication using a first radio access technology and a second communication unit configured to perform communication using a second radio access technology, by using the first access technology. The network apparatus comprises: a receiver configured to receive, from the user terminal, authentication related information on a country where the user terminal is legally authenticated for transmission by the second communication unit; and a controller configured to determine, based on the authentication related information, whether or not communication by the second communication unit can be configured to the user terminal.

Abstract: A communication control method is a method for performing offload to transfer a traffic load of a cellular base station to an access point. The communication control method comprises a step of maintaining without releasing the first connection, by a user terminal that have established a first connection with the cellular base station, even when the offload is started after establishing a second connection with the access point; and a determining step of determining, by the user terminal, whether the offload is continued or canceled after the offload is started.

Abstract: A base station 100 in a radio transmission system that performs multicast/broadcast transmission comprises a multiplexing unit 110 configured to multiplex a plurality of types of transmission data transmitted in schemes different in error tolerance; and a transmitter 120 configured to transmit multiplexed data obtained by the multiplexing unit 110, by multicast/broadcast. The plurality of types of transmission data includes basic transmission data transmitted, by the transmitter, in a scheme having a first error tolerance and additional transmission data transmitted, by the transmitter, in a scheme having a second error tolerance lower than the first error tolerance. The additional transmission data is utilized in a terminal 200 by being combined with the basic transmission data.

Abstract: A communication apparatus comprises: a first processing unit configured to perform processing of a first layer; and a second processing unit configured to perform processing of a second layer which is provided to be upper than the first layer. The second processing unit is configured to perform communication by using a first component carrier included in a licensed band and perform communication by using a second component carrier included in an unlicensed band. The first processing unit is configured to perform communication by using the first component carrier and performs communication by using an element carrier selected from among a plurality of element carriers associated with the second component carrier.

Abstract: A radio base station according to an embodiment constitutes a mobile communication network. The radio base station comprises: a controller configured to measure a stay time for which a radio terminal has stayed on a wireless LAN. The stay time is a period from when a first process through which the radio terminal switches a waiting destination or a connection destination from the mobile communication network to the wireless LAN is performed to when a second process through which the radio terminal switches the waiting destination or the connection destination from the wireless LAN to the mobile communication network is performed.

Abstract: A communication control method according to one embodiment comprises transmitting, by a first base station configured to manage a cell, a message to a second base station in a specific procedure; and storing, by the second base station that receives the message, information included in the message by associating with the cell. The information includes at least one of information related to a cell size of the cell and information related to a capability of the cell for dual connectivity communication.

Abstract: A base station and method thereof includes transmitting from the base station to a user equipment, parameters for an offload from the cellular RAN to a wireless local area network (LAN). The parameters are used by the user equipment to perform an access network selection between the cellular RAN and the wireless LAN, and include a first threshold for comparison with a cellular signal strength of the cellular RAN, a second threshold for comparison with a wireless LAN signal strength of the wireless LAN, and a third threshold for comparison with a load of the wireless LAN. When performing access network selection, the parameters may cause the user equipment to perform the offload, in response to the cellular signal strength being lower than the first threshold, the wireless LAN signal strength being higher than the second threshold, and the load of the wireless LAN being lower than the third threshold.

Abstract: A radio terminal includes a receiver, a controller, and a transmitter. The receiver receives first information on radio resources for direct communication from a base station by broadcast and second information on a threshold value from the base station. The controller performs the direct communication by use of a radio resource autonomously selected among the radio resources. The receiver directly receives a radio signal from another radio terminal during performing the direct communication by use of the radio resources, and the controller compares received power of the radio signal with the threshold value of the second information. The transmitter notifies the base station of first information on the received power in response to the received power being larger than the threshold value, and does not notify the base station of the information on the received power in response to the received power being smaller than the threshold value.

Abstract: A communication device according to one embodiment includes a controller and a transmitter. The controller is configured to identify a zone that is a geographical section where the communication device is located, and select a predetermined transmission resource region from a plurality of transmission resource regions included in one transmission resource pool associated with the identified zone. The transmitter is configured to transmit a direct radio signal to another communication device by using a resource in the predetermined transmission resource region.

Abstract: A communication system 1 comprises: a radio base station 100 having a first coverage area 100 A; an access point 200 having a second coverage area 200 A; and a detection assistance apparatus 300 having a third coverage area 300 A. A radio terminal 100 existing in the radio base station 100 starts a discovery procedure for the access point 200, after detecting a detection-use signal broadcast from the detection assistance apparatus 300.

Abstract: A communication control method according to a present embodiment comprises: a step of transmitting, by a first base station, to a third base station that is a neighboring base station of the first base station, a first resource message relating to a first D2D resource used for the D2D proximity service in the first base station. The first resource message includes information on the first D2D resource and a second D2D resource used for the D2D proximity service in a second base station that is a neighboring base station of the first base station.

Abstract: In the communication control method according to the present embodiment, a user terminal transmits a scheduling assignment indicating the location of a radio resource used in a reception of communication data by direct device-to-device communication. The user terminal transmits the communication data including initial transmission data and retransmission data by using the radio resource. The retransmission data is transmitted depending on the number of times of re-transmissions associated with a predetermined scheduling assignment by using a predetermined radio resource of which the location is indicated by the predetermined scheduling assignment.

Abstract: A communication control method, radio terminal and processor thereof include transmitting, by a base station, information on a priority to be used to establish a bearer for direct communication between terminals, receiving, by the radio terminal, the information on the priority from the base station, and establishing, by the radio terminal, a plurality of bearers in accordance with a priority of each of a plurality of pieces of data to be transmitted by the direct communication, on a basis of the information on the priority.

Abstract: A communication control method for performing an offload from a cellular RAN to a wireless LAN, includes a step of performing, by a user terminal, a network selection operation to select an appropriate access network with which a traffic of the user terminal is exchanged, from the cellular RAN and the wireless LAN on the basis of determination parameters. The determination parameters comprises at least one of: a cellular network status that is a network status concerning the cellular RAN; a wireless LAN network status that is a network status concerning the wireless LAN; a cellular radio link status that is a radio link status between the cellular RAN and the user terminal; and a wireless LAN radio link status that is a radio link status between the wireless LAN and the user terminal.

Abstract: A communication control method includes receiving MDT (Minimization of Drive Test) information, by a user equipment that supports a cellular communication and a WLAN (Wireless Local Area Network) communication, from a base station included in a cellular network, performing, by the user equipment, WLAN measurement on a WLAN access point, and transmitting an MDT report message to the base station, by the user equipment, where the MDT report message includes information indicating location of the user equipment and information indicating WLAN measurement result of the WLAN access point. The WLAN measurement result includes an identifier of the WLAN access point and signal strength of the WLAN access point.

Abstract: A base station manages a first cell and a second cell and communicates with a user terminal by carrier aggregation which is applied to the first cell and the second cell, the first cell being allocated a licensed band requiring a license and a second cell being allocated an unlicensed band not requiring a license. The base station includes: a transmitter configured to transmit a synchronization signal used for synchronization between the second cell and the user terminal, by at least one carrier selected from the unlicensed band based on a result of carrier sensing in the second cell; and a controller configured to instruct the user terminal to perform a detection operation of the synchronization signal for all or part of the carrier through the first cell.

Abstract: A master base station according to embodiment divides a bearer of a mobile station into two split bearers in a dual connectivity scheme. One split bearer is provided between the master base station and the mobile station without intervention of a secondary base station. Another split bearer is provided between the master base station and the mobile station with the intervention of a secondary base station. The master base station comprises a transmitter configured to transmit to the mobile station, information indicating whether the mobile station should transmit uplink data to the master station or to the secondary base station.