Abstract: A base station includes a memory holding information on P terminals in connecting to the base station, where P is an integer of 3 or more, a determination unit that determines L terminals to transmit a reference symbol used for measurement of channel state information indicating a state of a propagation path to the base station from among the P terminals based on the information on the P terminals, at every data transmission cycle, where L is an integer satisfying 2?L<P, a selector that selects M terminals capable of spatial multiplexing communication in the data transmission cycle based on a measurement result of the channel state information based on reception of the reference symbol transmitted from L terminals, where M is an integer satisfying 2?M?L, and receives respective pieces of data transmitted from the M terminals via a plurality of antennas.

Abstract: A shared frequency management system that manages sharing of frequencies of a shared frequency band mainly used by a first wireless system with a second wireless system, includes an input unit that receives first border information regarding a first border indicating a border of a first region in which a reception level based on transmission of a first wireless signal using the frequencies of the shared frequency band from the first wireless system becomes a defined value, a deriving unit that derives second border information regarding a second border indicating a border of a second region in which a reception level based on transmission of a second wireless signal using the frequencies of the shared frequency band from the second wireless system becomes the defined value, and a permission condition determination unit that determines a sharing permission condition regarding the frequencies of the shared frequency band for the second wireless system on the basis of the first border information and the second

Abstract: A communication charging system includes a first measuring device that measures an amount of communication established by a terminal in utilization of a first communication service using a first communication network and a second measuring device that measures an amount of communication established by the terminal in utilization of a second communication service using a second communication network. The first measuring device transmits information regarding the measured amount of communication in the utilization of the first communication service to the second measuring device. The second measuring device associates with information regarding the terminal and stores the information regarding the amount of communication in the utilization of the first communication service, which has been transmitted from the first measuring device, and information regarding the measured amount of communication in the utilization of the second communication service.

Abstract: A base station is capable of wireless communication with a plurality of terminals, the base station includes a memory that holds information on P (P: an integer of 3 or more) terminals currently connected to the base station, a determination unit that determines L (L: an integer satisfying 2?L<P) terminals that are to report channel state information indicating a state of a propagation path to the base station from among the P terminals based on the information on the P terminals, at every data transmission cycle, a selector that selects M (M: an integer satisfying 2?M?L) terminals capable of spatial multiplex communication in the data transmission cycle based on the reporting of the channel state information from the L terminals, and a communicator that transmits data to and from the M terminals via a plurality of antennas using the spatial multiplex communication.

Abstract: Provided is a wireless communication apparatus capable of improving communication quality and reducing a communication time delay in a case of communicating data over a backhaul line. The wireless communication apparatus is a wireless communication apparatus which communicates with another wireless communication apparatus over a wireless backhaul line in which a plurality of wireless communication schemes are mixed and used, and includes a processor that determines whether or not to add redundant data to data, in accordance with an allowable delay time of the data, and an antenna that transmits the data by adding or not adding the redundant data to the data, in accordance with a result of the determination.

Abstract: A wireless system includes a plurality of base stations including a first base station connected to a backbone network and a plurality of second base stations connected to the first base station by wireless multi-hop, and a server disposed in the backbone network and communicating with the first base station.

Abstract: Desired communication quality in relay for data transmission is secured, and stable radio communication is realized. An in-facility transmission system is disposed in a facility with a plurality of closed spaces, and includes a master base station that is disposed in a first closed space and performs a radio communication with an external base station provided outside the facility and a first slave base station that is disposed in a second closed space different from the first closed space and performs a radio communication with the master base station. The first closed space and the second closed space are connected to each other through a first radio waveguide capable of reducing a propagation loss of a radio wave in the radio communication between the master base station and the first slave base station.

Abstract: There is provided a radio communication terminal that can reduce power consumption by a radio communication terminal when searching for a radio base station apparatus that is to be connected to the radio communication terminal, and that can reduce the time it takes to search for the radio base station apparatus. The radio communication terminal communicates with a radio base station apparatus through a network in which a plurality of radio communication schemes are present for use in a mixed manner, and includes a processor and an antenna.

Abstract: Channel interference is suppressed, and an increase in the cost of manufacturing a terminal or in maximum transmission power is adaptively suppressed. A base station retains information relating to at least one already-allocated bandwidth, among all bandwidths that are to be used for wireless communication, in a memory and determines whether the already-allocated bandwidth that is the same as a bandwidth which satisfies terminal performance information, according to a request for communication from a terminal, which includes the terminal performance information is present or absent. In a case where the already-allocated bandwidth that is the same as the bandwidth which satisfies the terminal performance information is absent, the base station determines whether a non-allocated bandwidth that is the same as the bandwidth which satisfies the terminal performance information is present or absent.

Abstract: A thermoplastic polyester resin foam sheet including: a thermoplastic polyester resin; and at least one crystallization accelerator selected from an inorganic crystallization accelerator and an organic crystallization accelerator, wherein the thermoplastic polyester resin foam sheet has a crystallization time of 14 minutes or less, determined from a DSC curve obtained using a heat flux differential scanning calorimetry (DSC) apparatus by performing a second heating from 30° C. to 110° C. at a heating rate of 100° C./min, and holding the temperature at 110° C. for 30 minutes, wherein the crystallization time is determined in terms of a time between initiation of the second heating and a time of emergence of a peak top of a last appearing exothermic peak in the DSC curve.

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: 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: Provided is a wireless relay device that determines whether or not the wireless relay device has to withdraw from a first wireless multi-hop network to which the wireless relay device itself belong, transmits, in a wireless multi-hop, a request for a connection that uses wireless communication in compliance with a first communication scheme between the wireless relay device and at least one wireless base station, to a wireless base station on the first wireless multi-hop network, according to a result of the determination that the wireless relay device withdraws from the first wireless multi-hop network, and allocates the wireless communication in compliance with the first communication scheme between the wireless relay device and the at least one wireless base station according to a control signal that is transmitted from the wireless base station on the first wireless multi-hop network.

Abstract: A base station includes a memory holding information on P terminals in connecting to the base station, where P is an integer of 3 or more, a determination unit that determines L terminals to transmit a reference symbol used for measurement of channel state information indicating a state of a propagation path to the base station from among the P terminals based on the information on the P terminals, at every data transmission cycle, where L is an integer satisfying 2?L<P, a selector that selects M terminals capable of spatial multiplexing communication in the data transmission cycle based on a measurement result of the channel state information based on reception of the reference symbol transmitted from L terminals, where M is an integer satisfying 2?M?L, and receives respective pieces of data transmitted from the M terminals via a plurality of antennas.

Abstract: Base stations arranged in closed spaces perform wireless communication with another base station present in another closed space divided by shields with shields interposed therebetween. Low-loss parts at which a passage loss of radio waves of the wireless communication is low is formed at shields. Base stations obtain communication quality of a propagation channel with another wireless communication device, and form a directivity of the wireless communication such that the communication quality is equal to or greater than a predetermined value.

Abstract: A radio base station apparatus allocates a white space frequency to a wireless communication apparatus, and includes a radio resource allocating unit that allocates to the wireless communication apparatus a first white space frequency that the radio station apparatus allocates to another wireless communication apparatus, among a plurality of white space frequencies, according to an allocation request for a communication frequency from the wireless communication apparatus.

Abstract: A wireless terminal that: for previous communications between the wireless terminal and base stations, stores as a communication history at least position information for the wireless terminal and information pertaining to each base station; acquires the position information for the wireless terminal and, on the basis of the position information for the wireless terminal and the stored communication history, derives from multiple base stations at least a connection subject base station to be used in data communication and a connection standby base station, which is the base station having the next highest connection priority after the connection subject base station; and performs data communication when a trial connection with the connection subject base station has succeeded, and switches the connection subject base station to be used in data communication to the connection standby base station when communication with the connection subject base station is interrupted.

Abstract: A wireless base station extracts a connection base station which communicates user data with a wireless communication terminal from a plurality of other wireless base stations, and extracts an allocation candidate of a wireless frequency regarding communication of the user data between the connection base station and the wireless communication terminal based on information of an utilization result of a wireless frequency regarding communication of the user data of each of the other wireless base stations.

Abstract: A wireless terminal capable of communicating with multiple wireless base stations through a network in which multiple wireless communication methods are used in a mixed manner. A storage unit stores, as a communication history, at least location information for the wireless terminal and information pertaining to the wireless base station at the time of communication with each wireless base station. An acquisition unit acquires the location information for the wireless terminal. On the basis of the acquired location information for the wireless terminal and the communication history stored in the storage unit a derivation unit derives a connection base station from the multiple wireless base stations, as the wireless base station to be used in data communication. A communication unit performs data communication with the derived connection base station.