Abstract: A valve device includes a rotation shaft, a valve body, and a biasing portion. The valve body is configured to be rotationally displaceable about the rotation shaft between a closed position and an open position. The biasing portion biases the valve body so as to cause the valve body to approach the closed position. The valve body includes an upstream wall arranged in a position upstream of the rotation shaft in a flow direction of the fluid when the valve body is in the closed position. The valve body includes a rotation end, which is an end distal from the rotation shaft and moves downstream in the flow direction of the fluid in response to a displacement of the valve body from the closed position to the open position, and the rotation end is shaped to project upstream when the valve body is in the closed position.

Abstract: In a “local production for local consumption” network including a backhaul line formed by wireless multi-hop communication between a plurality of base stations, and a plurality of local service servers, communication speed is increased by appropriately selecting communication routes between the user terminals and the local service servers, and the power efficiency of the wireless communication by minimizing the power consumption of the overall system. A network control server collects information regarding the user terminals, the access points, and the local service servers, sets communication routes between the user terminals and the local service servers, groups of the base stations, those of the existing base stations and local service servers that are active so as to optimize a power efficiency of the overall network according to the collected information, and notifies the base stations, the local service servers or the user terminals of route information regarding the communication routes.

Abstract: In a network having an edge server disposed therein, to appropriately construct a wireless communication route used in communication between the edge server and a user terminal, a processor of a network control device acquires group information related to grouped base stations in multiple base stations disposed in the network, acquires route information related to one or more wireless communication routes formed by multi-hop communication between the grouped base stations, and transmits the group information and the route information to an edge server connected to one of the base stations or to a user terminal.

Abstract: A communication device includes a wireless communication device, a location information acquisition device, a storage and a controller. The wireless communication device wirelessly communicates with a base station used as a connection destination. The location information acquisition device acquires location information on a location of the communication device. The storage stores historical communication information on past communication status. The controller determines a degree of risk of occurrence of reduction in an amount of available communication bandwidth beyond a tolerance limit based on the historical communication information and the location information. The controller further controls a transmission rate for communicating the data based on a result of determination of the degree of risk.

Abstract: A wireless system can use a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, and includes a communication unit performing wireless communication with a terminal accommodated in a communication area, at least one sensor disposed around the communication area and measuring reception power of a signal sent from the inside of the communication area via the communication unit, a memory storing beam data indicating a correspondence relationship between a beam direction of the signal and a measurement result in the sensor, a determination unit determining allowable maximum transmission power of the signal in each beam direction on the basis of the sharing conditions and the beam data, and an allocation unit allocating a radio resource to the terminal on the basis of the allowable maximum transmission power in each beam direction and channel state information reported from the terminal.

Abstract: In order to prospectively avoid communication failures or reduction in throughput of each user terminal, thereby improving users' satisfaction with communication service, a base station is configured to control wireless communication with a terminal device by using any of multiple transmission beams formed by the base station or those formed by another base station and includes a wireless communication device and a controller configured to acquire correction information used for correcting a measurement value for evaluating reception status of each transmission beam and cause the wireless communication device to transmit the correction information to the user terminal so as to thereby promote the user terminal to use, or inhibit the user terminal from using a specific transmission beam.

Abstract: A wireless system can use a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, and includes a communication unit performing wireless communication with a terminal accommodated in a communication area, at least one sensor disposed around the communication area and measuring reception power of a signal sent from the inside of the communication area via the communication unit, a memory storing beam data indicating a correspondence relationship between a beam direction of the signal and a measurement result in the sensor, a determination unit determining allowable maximum transmission power of the signal in each beam direction on the basis of the sharing conditions and the beam data, and an allocation unit allocating a radio resource to the terminal on the basis of the allowable maximum transmission power in each beam direction and channel state information reported from the terminal.

Abstract: To reduce power consumption and enable a quick change from one communication path to another when detecting a decrease in quality of communication for communicating user data, a first base station determines a second base station and a third base station, and then the first base station transmits a connection request message to a terminal, the second base station and the third base station concurrently with transmitting a communication request message to the second base station, and, while the second base station is in communication with the terminal, upon detecting a decrease in quality of communication with the terminal based on a reception status of an uplink signal from the terminal, the second base station transmits a path switching request message to the first base station, which in turn transfers the received path switching request message transmitted from the second base station to the third base station.

Abstract: To reduce power consumption and enable a quick change from one communication path to another when detecting a decrease in quality of communication for communicating user data, a first base station determines a second base station and a third base station, and then the first base station transmits a connection request message to a terminal, the second base station and the third base station concurrently with transmitting a communication request message to the second base station, and, while the second base station is in communication with the terminal, upon detecting a decrease in quality of communication with the terminal based on a reception status of an uplink signal from the terminal, the second base station transmits a path switching request message to the first base station, which in turn transfers the received path switching request message transmitted from the second base station to the third base station.

Abstract: A shared frequency management apparatus includes a communicator receiving application information regarding use of a shared frequency band from each of base stations of plural different communication companies, a determiner determining whether or not allocation of different TDD patterns during use of adjacent carrier frequencies among plural carrier frequencies included in the shared frequency band is possible on the basis of the application information from each base station, a setter setting the TDD pattern for each of the carrier frequencies on the basis of the application information from each base station and a determination result of whether or not allocation of the different TDD patterns is possible, and a decision unit deciding an allocation content of the shared frequency band to each base station, satisfying the application information from each base station, on the basis of a setting result of the TDD pattern for each carrier frequency.

Abstract: A wireless communication system includes a first base station connectable to a backbone network by a wireless backhaul, and a path generator generating a wireless multi-hop path including the first base station and one or more second base stations connected to the first base station by a wireless multi-hop. The first base station reports a measurement result of a line quality of the wireless backhaul and a measurement result of a line quality between the first base station and the second base station disposed around the first base station. The first base station is switched to a first mode connected to the backbone network by the wireless backhaul or to a second mode connected to the second base station by a wireless multi-hop, in response to the path signal.

Abstract: A communication device includes a wireless communication device, a location information acquisition device, a storage and a controller. The wireless communication device wirelessly communicates with a base station used as a connection destination. The location information acquisition device acquires location information on a location of the communication device. The storage stores historical communication information on past communication status. The controller determines a degree of risk of occurrence of reduction in an amount of available communication bandwidth beyond a tolerance limit based on the historical communication information and the location information. The controller further controls a transmission rate for communicating the data based on a result of determination of the degree of risk.

Abstract: A wireless receiver measures a reception parameter while scanning multiple pieces of reception directivity for an interval during which a signal is not transmitted from a wireless transmitter. The wireless transmitter transmits a signal while scanning multiple pieces of transmission directivity, and the wireless receives measures a reception parameter relating to reception of the signal and determines k pieces of transmission directivity that correspond to high-ranking k results, respectively, of the measurement that have a great reception parameter. The wireless transmitter forms any transmission directivity and transmits a signal, and the wireless receives measures a reception parameter while scanning M pieces of reception directivity and determines reception directivity that is to be used for data communication.

Abstract: In order to enable efficient utilization of an available bandwidth by properly estimating the available bandwidth under conditions in which the available bandwidth significantly changes upon occurrence of communication path switching, an available bandwidth estimation is performed by estimating a current available bandwidth based on historical communication state information i.e.

Abstract: A communication device is provided and includes: a wireless communication device configured to wirelessly communicate with a base station used as a connection destination; a location information acquisition device configured to acquire location information on a location of the communication device; a storage configured to store historical obstruction information for an obstructed location where decrease in communication quality due to obstruction has occurred before; a controller configured to determine, based on the historical obstruction information and the location information, a degree of risk of occurrence of decrease in communication quality due to obstruction for at least one of a current connection destination that is currently used by the communication device and a future connection destination that is expected to be used by the communication device, and control the connection destination based on a result of determination of the degree of risk.

Abstract: A base station holds information on uplink radio resources which has been allocated to at least one already connected communication terminal for performing radio communication using a high frequency with the base station, receives a notification of participation in a radio communication system from a new communication terminal, and allocates unallocated uplink radio resources using high frequencies to the new communication terminal based on the information on the uplink radio resources when received the notification of participation. The new communication terminal transmits data to the base station by using the allocated uplink radio resources.

Abstract: Provided is a communication terminal configured to communicate with base stations, including a memory and a processor. The processor executes a position acquisition task that acquires position information on the communication terminal, an accumulation task that accumulates connection frequency information and discontinuance frequency information that relate to communication with each of the base stations at a position of the communication terminal, a determination task that determines a connection priority for preferentially making a connection to each of the base stations from a position of the communication terminal, based on the connection frequency information and the discontinuance frequency information at the position of the communication terminal, a connection control task that controls a connection to each of one or more base stations, in a descending order of the determined connection priority, and a communication task that performs data communication with the one or more base stations.

Abstract: In order to prospectively avoid communication failures or reduction in throughput of each user terminal, thereby improving users' satisfaction with communication service, a base station is configured to control wireless communication with a terminal device by using any of multiple transmission beams formed by the base station or those formed by another base station and includes a wireless communication device and a controller configured to acquire correction information used for correcting a measurement value for evaluating reception status of each transmission beam and cause the wireless communication device to transmit the correction information to the user terminal so as to thereby promote the user terminal to use, or inhibit the user terminal from using a specific transmission beam.

Abstract: A shared frequency management apparatus includes a communicator receiving application information regarding use of a shared frequency band from each of base stations of plural different communication companies, a determiner determining whether or not allocation of different TDD patterns during use of adjacent carrier frequencies among plural carrier frequencies included in the shared frequency band is possible on the basis of the application information from each base station, a setter setting the TDD pattern for each of the carrier frequencies on the basis of the application information from each base station and a determination result of whether or not allocation of the different TDD patterns is possible, and a decision unit deciding an allocation content of the shared frequency band to each base station, satisfying the application information from each base station, on the basis of a setting result of the TDD pattern for each carrier frequency.

Abstract: A wireless system can use a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, and includes a communication unit performing wireless communication with a terminal accommodated in a communication area, at least one sensor disposed around the communication area and measuring reception power of a signal sent from the inside of the communication area via the communication unit, a memory storing beam data indicating a correspondence relationship between a beam direction of the signal and a measurement result in the sensor, a determination unit determining allowable maximum transmission power of the signal in each beam direction on the basis of the sharing conditions and the beam data, and an allocation unit allocating a radio resource to the terminal on the basis of the allowable maximum transmission power in each beam direction and channel state information reported from the terminal.