Abstract: Provided is a technology that can maintain the reliability and the transmission rate in the communication. A communication system includes a communication terminal, and a first base station and a second base station that are configured to perform radio communication with the communication terminal. The first base station notifies the second base station of information on a numerology to be used for communication between the first base station and the communication terminal when the first base station and the second base station provide the communication terminal with dual connectivity using a same frequency band (Steps ST1501 and ST1502).

Abstract: A mobile communication system, which changes a communication partner of a mobile terminal from an originating base station to a destination base station, wherein a request message requesting to become a candidate is transmitted to a plurality of candidate base stations, which are potential destination base stations, from the originating base station, a response message responding to the request message is transmitted from the plurality of candidate base stations to the originating base station, and information of the candidate base stations is transmitted from the originating base station to the mobile terminal.

Abstract: A communication system includes a base station configuring an energy saving cell (ES cell) and a base station configuring a compensation cell (Comp cell). The ES cell is switchable between a switch-on state and a switch-off state. The Comp cell compensates for the coverage of the ES cell when the ES cell is in the switch-off state. Before the Comp cell starts compensating for the coverage, for example, before the ES cell decides to switch itself off in Step ST2101, in Step ST2201 for example, the base station configuring the ES cell notifies the UE being connected with the ES cell of the information about a Comp cell, for example, a Comp cell list.

Abstract: Provided is a technology that can maintain the reliability and the transmission rate in the communication. A communication system includes a communication terminal, and a first base station and a second base station that are configured to perform radio communication with the communication terminal. The first base station notifies the second base station of information on a numerology to be used for communication between the first base station and the communication terminal when the first base station and the second base station provide the communication terminal with dual connectivity using a same frequency band (Steps ST1501 and ST1502).

Abstract: A communication system includes a base station configuring an energy saving cell (ES cell) and a base station configuring a compensation cell (Comp cell). The ES cell is switchable between a switch-on state and a switch-off state. The Comp cell compensates for the coverage of the ES cell when the ES cell is in the switch-off state. Before the Comp cell starts compensating for the coverage, for example, before the ES cell decides to switch itself off in Step ST2101, in Step ST2201 for example, the base station configuring the ES cell notifies the UE being connected with the ES cell of the information about a Comp cell, for example, a Comp cell list.

Abstract: A communication system includes a base station configuring an energy saving cell (ES cell) and a base station configuring a compensation cell (Comp cell). The ES cell is switchable between a switch-on state and a switch-off state. The Comp cell compensates for the coverage of the ES cell when the ES cell is in the switch-off state. Before the Comp cell starts compensating for the coverage, for example, before the ES cell decides to switch itself off in Step ST2101, in Step ST2201 for example, the base station configuring the ES cell notifies the UE being connected with the ES cell of the information about a Comp cell, for example, a Comp cell list.

Abstract: A communication system includes a base station configuring an energy saving cell (ES cell) and a base station configuring a compensation cell (Comp cell). The ES cell is switchable between a switch-on state and a switch-off state. The Comp cell compensates for the coverage of the ES cell when the ES cell is in the switch-off state. Before the Comp cell starts compensating for the coverage, for example, before the ES cell decides to switch itself off in Step ST2101, in Step ST2201 for example, the base station configuring the ES cell notifies the UE being connected with the ES cell of the information about a Comp cell, for example, a Comp cell list.

Abstract: A communication system includes a base station configuring an energy saving cell (ES cell) and a base station configuring a compensation cell (Comp cell). The ES cell is switchable between a switch-on state and a switch-off state. The Comp cell compensates for the coverage of the ES cell when the ES cell is in the switch-off state. Before the Comp cell starts compensating for the coverage, for example, before the ES cell decides to switch itself off in Step ST2101, in Step ST2201 for example, the base station configuring the ES cell notifies the UE being connected with the ES cell of the information about a Comp cell, for example, a Comp cell list.

Abstract: In a communication system of the present invention, a HeNB measures interference in Step ST41 in an energy saving mode. When judging to have detected the interference by a UE during communication with an eNB in Step ST42, the HeNB cancels the energy saving mode and moves to a normal mode in Step ST43 and starts issuing a pilot signal in Step ST44. When the UE judges to have detected the pilot signal in Step ST23 and reports the judgment results to the eNB in Step ST24, in Steps ST25 to ST32, a handover process from the eNB to the HeNB is performed for the UE.

Abstract: A communication system includes a base station configuring an energy saving cell (ES cell) and a base station configuring a compensation cell (Comp cell). The ES cell is switchable between a switch-on state and a switch-off state. The Comp cell compensates for the coverage of the ES cell when the ES cell is in the switch-off state. Before the Comp cell starts compensating for the coverage, for example, before the ES cell decides to switch itself off in Step ST2101, in Step ST2201 for example, the base station configuring the ES cell notifies the UE being connected with the ES cell of the information about a Comp cell, for example, a Comp cell list.

Abstract: In a communication system of the present invention, a HeNB measures interference in Step ST41 in an energy saving mode. When judging to have detected the interference by a UE during communication with an eNB in Step ST42, the HeNB cancels the energy saving mode and moves to a normal mode in Step ST43 and starts issuing a pilot signal in Step ST44. When the UE judges to have detected the pilot signal in Step ST23 and reports the judgment results to the eNB in Step ST24, in Steps ST25 to ST32, a handover process from the eNB to the HeNB is performed for the UE.

Abstract: A communication system includes a base station configuring an energy saving cell (ES cell) and a base station configuring a compensation cell (Comp cell). The ES cell is switchable between a switch-on state and a switch-off state. The Comp cell compensates for the coverage of the ES cell when the ES cell is in the switch-off state. Before the Comp cell starts compensating for the coverage, for example, before the ES cell decides to switch itself off in Step ST2101, in Step ST2201 for example, the base station configuring the ES cell notifies the UE being connected with the ES cell of the information about a Comp cell, for example, a Comp cell list.

Abstract: In a communication system of the present invention, a HeNB measures interference in Step ST41 in an energy saving mode. When judging to have detected the interference by a UE during communication with an eNB in Step ST42, the HeNB cancels the energy saving mode and moves to a normal mode in Step ST43 and starts issuing a pilot signal in Step ST44. When the UE judges to have detected the pilot signal in Step ST23 and reports the judgment results to the eNB in Step ST24, in Steps ST25 to ST32, a handover process from the eNB to the HeNB is performed for the UE.

Abstract: In a communication system, a HeNB measures interference in an energy saving mode. When judging to have detected the interference by a UE during communication with an eNB, the HeNB cancels the energy saving mode and moves to a normal mode and starts issuing a pilot signal. When the UE judges to have detected the pilot signal and reports the judgment results to the eNB, a handover process from the eNB to the HeNB is performed for the UE.

Abstract: A communication system includes a base station configuring an energy saving cell (ES cell) and a base station configuring a compensation cell (Comp cell). The ES cell is switchable between a switch-on state and a switch-off state. The Comp cell compensates for the coverage of the ES cell when the ES cell is in the switch-off state. Before the Comp cell starts compensating for the coverage, for example, before the ES cell decides to switch itself off in Step ST2101, in Step ST2201 for example, the base station configuring the ES cell notifies the UE being connected with the ES cell of the information about a Comp cell, for example, a Comp cell list.

Abstract: In a communication system, a HeNB measures interference in an energy saving mode. When judging to have detected the interference by a UE during communication with an eNB, the HeNB cancels the energy saving mode and moves to a normal mode and starts issuing a pilot signal. When the UE judges to have detected the pilot signal and reports the judgment results to the eNB, a handover process from the eNB to the HeNB is performed for the UE.

Abstract: A directional coupler capable of improving a directionality of a directional coupler body including four terminals. The directional coupler includes a directional coupler body including the four terminals of an input port, an output port, a coupling port, and an isolation port; and a combiner for combining powers of an output signal of the coupling port and an output signal of the isolation port of the directional coupler body; and a directionality improving circuit for amplifying or attenuating at least one of the output signal of the coupling port and the output signal of the isolation port before outputting the same, and the combiner combines powers of the output signals amplified or attenuated by the directionality improving circuit.

Abstract: A directional coupler capable of improving a directionality of a directional coupler body including four terminals. The directional coupler includes a directional coupler body including the four terminals of an input port, an output port, a coupling port, and an isolation port; and a combiner for combining powers of an output signal of the coupling port and an output signal of the isolation port of the directional coupler body; and a directionality improving circuit for amplifying or attenuating at least one of the output signal of the coupling port and the output signal of the isolation port before outputting the same, and the combiner combines powers of the output signals amplified or attenuated by the directionality improving circuit.