Abstract: An LTE system includes an eNB 200-2 configured to support D2D communication which is one of LTE communication schemes and in which communication is directly performed between proximal devices, and an eNB 200-1 included in an LTE network. A communication control method includes: a step S11 of requesting, by the eNB 200-2, an allocation of a D2D communication resource to the eNB 200-1; a step S12 of allocating, by the eNB 200-1, on the basis of the request from the eNB 200-2, the D2D communication resource from a specific frequency band shared by a plurality of mobile network operators or a plurality of communication systems, to the eNB 200-2; and a step S16 of performing, by the eNB 200-2, the D2D communication by using the D2D communication resource allocated from the eNB 200-1.

Abstract: An MBMS control method comprises the steps of: transmitting, by a eNB 200 included in the network, an MBMS counting request for counting UE 100s that either receive or have an interest in receiving the MBMS service, by using a predetermined signal that can be received by a user terminal in an RRC idle state; receiving, by an MBMS-compliant UE 100 that supports MBMS reception, the MBMS counting request transmitted by using the predetermined signal, in the RRC idle state; and performing, by the MBMS-compliant UE 100, a predetermined operation for transmitting an MBMS counting response, on the basis of the received MBMS counting request.

Abstract: eNB 200 controls wireless connections established by UE 100-1 with other communication apparatuses. The eNB 200 performs control such that number of the wireless connections established by the UE 100-1 is equal to or less than a connection allowance number indicating an upper limit number of the wireless connections allowed to the UE 100-1.

Abstract: eNB 200 controls a UE group including a plurality of UEs 100 (UE 100-1 and UE 100-2) that support cellular communication and D2D communication. The eNB 200 selects a communication mode for applying to the UE group from the cellular communication and the D2D communication, based on first channel information on a channel state between the UEs 100 (UE-UE) included in the UE group and second channel information on a channel state between the eNB 200 and the UEs 100 included in the UE group (UE-eNB).

Abstract: A first user terminal according to an embodiment comprises: at least one processor and at least one memory coupled to the processor. The processor is configured to perform processes of: determining first radio resources to be used for transmitting control information, the control information indicating location of second radio resources to be used for transmitting data by direct Device-to-Device communication; and directly transmitting the same control information repeatedly to a second user terminal in each resource block included in the first control resources.

Abstract: A mobile communication system which supports D2D communication that is direct inter-terminal radio communication, comprises: a user terminal that transmits and receives discovery signals for a discovery process of a communication target terminal of the D2D communication; and a base station that transmits discovery resource information indicating radio resources to be used for transmitting and receiving the discovery signals. The user terminal transmits and receives the discovery signals when the discovery resource information is received from the base station, by using the radio resource indicated by the received discovery resource information.

Abstract: A mobile communication system which supports D2D communication that is direct inter-terminal radio communication, comprises: a user terminal that transmits and receives discovery signals for a discovery process of a communication target terminal of the D2D communication; and a base station that transmits discovery resource information indicating radio resources to be used for transmitting and receiving the discovery signals. The user terminal transmits and receives the discovery signals when the discovery resource information is received from the base station, by using the radio resource indicated by the received discovery resource information.

Abstract: When a UE 100-2 (a reception-side UE) that performs D2D communication by using UL radio resource switches communication modes between cellular communication and the D2D communication, if DL subframe in which data reception of the cellular communication should be performed and the UL subframe in which data reception of the D2D communication should be performed at least partially overlap on a time axis, then the UE 100-2 performs data reception in one subframe, out of the overlapping two subframes.

Abstract: User terminal comprises a transmitter configured to transmit, in response to a received power of a signal from another user terminal satisfying a predetermined condition, direct communication in a proximity service without transmitting a synchronization signal in the proximity service, in a case where the user terminal is out of a network coverage.

Abstract: eNB 200 sets discovery resources that are radio resources used for transmission or reception of a discovery signal for performing the D2D communication. The eNB 200 controls a quantity (time length) of the discovery resources based on information on UE 100 existing in a target area that is a setting target area of the discovery resources.

Abstract: eNB 200 performs control on UE 100 that transmits or receives the periodical discovery signal by using the first radio resource. The eNB 200 notifies the UE 100 of a second radio resource for transmitting or receiving the non-periodical discovery signal between the UE 100 and a different UE 100 associated with the UE 100. The UE 100 uses the second radio resource to transmit or receive the non-periodical discovery signal.

Abstract: A communication control method according to the present invention comprises: notifying, by the base station, the at least one or more communication devices of reference signal configuration information designating a parameter of the uplink reference signal; transmitting, by the user terminal, the uplink reference signal to the base station; and receiving, on the basis of the reference signal configuration information, by the at least one or more communication devices, the uplink reference signal transmitted from the user terminal; and measuring, on the basis of the received uplink reference signal, by the at least one or more communication devices, a channel state between the at least one or more communication devices and the user terminal.

Abstract: A controller performs a mediation of an assigned radio resource such that the radio resource assigned to each of a plurality of other user terminals does not overlap each other, in a case where a transmission of user data is not performed among each of the plurality of other user terminals through D2D communication, and in a case where each of the plurality of other user terminals assigns the radio resource for transmitting the user data through the D2D communication.

Abstract: When a UE 100-2 (a reception-side UE) that performs D2D communication by using UL radio resource switches communication modes between cellular communication and the D2D communication, if DL subframe in which data reception of the cellular communication should be performed and the UL subframe in which data reception of the D2D communication should be performed at least partially overlap on a time axis, then the UE 100-2 performs data reception in one subframe, out of the overlapping two subframes.

Abstract: A mobile communication system performs downlink multi-antenna transmission by applying a precoder matrix that defines transmission directionality of downlink and a rank that defines number of signal sequences of the downlink. The mobile communication system comprises a user terminal that feeds back feedback information of a target frequency band, to a base station. The feedback information includes combinations of precoder matrix information indicating the precoder matrix and rank information indicating the rank.

Abstract: A mobile communication system which supports D2D communication that is direct inter-terminal radio communication, comprises: a user terminal that transmits and receives discovery signals for a discovery process of a communication target terminal of the D2D communication; and a base station that transmits discovery resource information indicating radio resources to be used for transmitting and receiving the discovery signals. The user terminal transmits and receives the discovery signals when the discovery resource information is received from the base station, by using the radio resource indicated by the received discovery resource information.