Abstract: A base station having an upper limit of total downlink transmission power includes a monitoring unit that monitors the total downlink transmission power, and a control unit that, when the total downlink transmission power is equal to or higher than a threshold, changes a transmission destination of data addressed to a first user terminal from the first user terminal to a second user terminal, the second user terminal being capable of direct communication with the first user terminal without requiring the base station between the second user terminal and the first user terminal, the second user terminal having, as downlink transmission power from the base station, second downlink transmission power lower than first downlink transmission power to the first user terminal.

Abstract: In a wireless communication system including a wireless terminal, a plurality of wireless base stations that wirelessly communicate with the wireless terminal, and a controller that changes the path used for communication with the wireless terminal from a first path via a first wireless base station to a second path via a second wireless base station, the controller monitors the amount of remaining data to the wireless terminal at the first wireless base station, controls to the timing to change to the second path according to the monitor result.

Abstract: A mobile communication system includes a plurality of base stations, an upper node, and a mobile station. In this mobile communication system, while a first base station that is currently connected via radio to the mobile station is receiving a first downlink signal from a second base station that was previously connected via radio to the mobile station and that received the first downlink signal from the upper node for transmission to the mobile station, when the mobile station is connected via radio to a third base station as a result of a handover, the first base station sends a redirection request signal requesting the second base station to redirect the first downlink signal to the third base station. Then, in response to the redirection request signal, the second base station redirects the first downlink signal to the third base station.

Abstract: A mobile communication system includes a plurality of base stations, an upper node, and a mobile station. In this mobile communication system, while a first base station that is currently connected via radio to the mobile station is receiving a first downlink signal from a second base station that was previously connected via radio to the mobile station and that received the first downlink signal from the upper node for transmission to the mobile station, when the mobile station is connected via radio to a third base station as a result of a handover, the first base station sends a redirection request signal requesting the second base station to redirect the first downlink signal to the third base station. Then, in response to the redirection request signal, the second base station redirects the first downlink signal to the third base station.

Abstract: In a wireless communication system including a wireless terminal, a plurality of wireless base stations that wirelessly communicate with the wireless terminal, and a controller that changes the path used for communication with the wireless terminal from a first path via a first wireless base station to a second path via a second wireless base station, the controller monitors the amount of remaining data to the wireless terminal at the first wireless base station, controls to the timing to change to the second path according to the monitor result.