Abstract: A base station apparatus includes a processor, a memory and a communication circuit. The processor is configured to set a waiting period in which a packet from a terminal device to which a connection has not been established is awaited. The memory is configured to store data that is processed by a terminal device to which a connection is established. The communication circuit is configured to, upon receiving a first packet from a communication terminal device in the waiting period, transmit to the communication terminal device a second packet containing the data and information used by the communication terminal device for establishing a connection.

Abstract: A wireless communication system includes a transmission device, a relay device, and a reception device and is configured to execute direct communication of directly transmitting a wireless signal from the transmission device to the reception device without routing through the relay device and indirect communication of indirectly transmitting a wireless signal from the transmission device to the reception device through the relay device. The wireless communication system includes a controller configured to estimate a disconnection continuation time that is a time during which the direct communication is not executable in a case where the direct communication is not executable while the direct communication is repeatedly executed, continue to execute the direct communication when the disconnection continuation time is shorter than a threshold time, and execute the indirect communication when the disconnection continuation time is longer than the threshold time.

Abstract: A BAN system includes multiple terminal apparatuses connected by wireless communication, where a terminal apparatus of the multiple terminal apparatuses is configured to identify in which direction acceleration has changed, the direction being identified based on a measurement result of a sensor of the terminal apparatus, the sensor being configured to measure acceleration; and to refer to information that specifies corresponding to places where the plurality of terminal apparatuses is to be attached to a body, directions in which acceleration changes when the body performs a given behavior, and determines based on the identified direction, a place where the terminal apparatus is attached to the body.

Abstract: A wireless communication system includes first and second wireless communication apparatuses. The first wireless communication apparatus includes a plurality of communication units that perform communication in different frequency bands. The plurality of communication units transmits the same control signal and data in the different frequency bands to keep allocation of communication slots for the second wireless communication apparatus on a plurality of paths. When detecting a communication failure while connecting to and communicating with one communication unit through one path, the second wireless communication apparatus switches to another communication unit and continues the communication through another path.

Abstract: A BAN system includes multiple terminal apparatuses connected by wireless communication, where a terminal apparatus of the multiple terminal apparatuses is configured to identify in which direction acceleration has changed, the direction being identified based on a measurement result of a sensor of the terminal apparatus, the sensor being configured to measure acceleration; and to refer to information that specifies corresponding to places where the plurality of terminal apparatuses is to be attached to a body, directions in which acceleration changes when the body performs a given behavior, and determines based on the identified direction, a place where the terminal apparatus is attached to the body.

Abstract: A wireless communication system includes a transmission device, a relay device, and a reception device and is configured to execute direct communication of directly transmitting a wireless signal from the transmission device to the reception device without routing through the relay device and indirect communication of indirectly transmitting a wireless signal from the transmission device to the reception device through the relay device. The wireless communication system includes a controller configured to estimate a disconnection continuation time that is a time during which the direct communication is not executable in a case where the direct communication is not executable while the direct communication is repeatedly executed, continue to execute the direct communication when the disconnection continuation time is shorter than a threshold time, and execute the indirect communication when the disconnection continuation time is longer than the threshold time.

Abstract: A wireless communication system includes first and second wireless communication apparatuses. The first wireless communication apparatus includes a plurality of communication units that perform communication in different frequency bands. The plurality of communication units transmits the same control signal and data in the different frequency bands to keep allocation of communication slots for the second wireless communication apparatus on a plurality of paths. When detecting a communication failure while connecting to and communicating with one communication unit through one path, the second wireless communication apparatus switches to another communication unit and continues the communication through another path.

Abstract: A wireless communication device includes a circuit board to include an antenna element, an estimating unit to estimate a current distribution in at least a partial area on the circuit board, which is induced by power feeding to the antenna element, and a specifying unit to specify a radiation pattern associated with the current distribution estimated by the estimating unit as a radiation directivity of the circuit board.

Abstract: A biological information measurement apparatus includes an electromagnetic wave applying unit configured to apply, to a living body, a first electromagnetic wave and a second electromagnetic wave having a frequency different from a frequency of the first electromagnetic wave; a reflected wave receiver configured to receive a first reflected wave corresponding to the first electromagnetic wave and a second reflected wave corresponding to the second electromagnetic wave; a correlation value configured to calculate unit calculating a correlation value between the first and second reflected waves; a correlation value evaluating unit configured to determine whether the correlation value satisfies a given condition; and a biological information measuring unit configured to measure biological information based on the first or second reflected wave when the correlation value evaluating unit determines that the correlation value satisfies the given condition.

Abstract: A variable directional antenna by means of a microstrip antenna and reactance change. The variable directional antenna has a structure to reduce sidelobes occurring when an element interval is reduced, and is structured in a three-element plane, having a feeding element and non-feeding elements provided at both sides of the feeding element. Each of the non-feeding elements provided at both sides of the feeding element has two split non-feeding elements two-divided into sizes of 1:2 in the lateral direction. The split non-feeding element divided into the size 1 is provided closer to the feeding element, and a reactance variable part is connected with the split non-feeding element divided into the size of 2. Alternatively, each of the non-feeding elements provided at both sides of the feeding element has two split non-feeding elements two-divided into sizes of 2:1 in the lateral direction.

Abstract: A wireless communication device includes a transmitter configured to transmit test signals a predetermined number of times at an interval shorter than a transmission interval of data signals and a processor configured to measure reception status of a plurality of acknowledgement signals transmitted back in response to the respective test signals transmitted by the transmitter.

Abstract: A wireless communication device includes a first wireless unit a first wireless unit processing a first radio signal propagated through a space; a second wireless unit processing a second radio signal propagated along the surface of a human body or in the human body; and a control unit selecting, as a present radio signal, any one of the first radio signal and the second radio signal, and controlling the first wireless unit and the second wireless unit so as to process the present radio signal.

Abstract: A radio communication device for communicating sensor information includes an electromagnetic wave communication unit using electromagnetic waves using the air as a propagation path, an ultrasonic communication unit using ultrasonic waves using an inside of a living body as a propagation path, and a midair/living-body switching control unit for switching between a communication performed by the electromagnetic wave communication unit and a communication performed by the ultrasonic wave communication unit.

Abstract: A wireless communication device includes a circuit board to include an antenna element, an estimating unit to estimate a current distribution in at least a partial area on the circuit board, which is induced by power feeding to the antenna element, and a specifying unit to specify a radiation pattern associated with the current distribution estimated by the estimating unit as a radiation directivity of the circuit board.

Abstract: At least two antennas are selected from a plurality of antennas which consist of at least two antennas having polarization characteristics or directivities different from one another, and which are arranged such that spatial fading correlations between the antennas are low, and a multiple input multiple output communication is conducted by using the selected antennas.

Abstract: A variable directional antenna by means of a microstrip antenna and reactance change. The variable directional antenna has a structure to reduce sidelobes occurring when an element interval is reduced, and is structured in a three-element plane, having a feeding element and non-feeding elements provided at both sides of the feeding element. Each of the non-feeding elements provided at both sides of the feeding element has two split non-feeding elements two-divided into sizes of 1:2 in the lateral direction. The split non-feeding element divided into the size 1 is provided closer to the feeding element, and a reactance variable part is connected with the split non-feeding element divided into the size of 2. Alternatively, each of the non-feeding elements provided at both sides of the feeding element has two split non-feeding elements two-divided into sizes of 2:1 in the lateral direction.

Abstract: A biological information measurement apparatus includes an electromagnetic wave applying unit configured to apply, to a living body, a first electromagnetic wave and a second electromagnetic wave having a frequency different from a frequency of the first electromagnetic wave; a reflected wave receiver configured to receive a first reflected wave corresponding to the first electromagnetic wave and a second reflected wave corresponding to the second electromagnetic wave; a correlation value configured to calculate unit calculating a correlation value between the first and second reflected waves; a correlation value evaluating unit configured to determine whether the correlation value satisfies a given condition; and a biological information measuring unit configured to measure biological information based on the first or second reflected wave when the correlation value evaluating unit determines that the correlation value satisfies the given condition.

Abstract: A wireless communication device includes a first wireless unit a first wireless unit processing a first radio signal propagated through a space; a second wireless unit processing a second radio signal propagated along the surface of a human body or in the human body; and a control unit selecting, as a present radio signal, any one of the first radio signal and the second radio signal, and controlling the first wireless unit and the second wireless unit so as to process the present radio signal.

Abstract: A control device for an antenna matching circuit is configured to output an adjusting signal for changing impedance of an element in the antenna matching circuit based on change over time in signal power ratio of a reflected signal from the antenna matching circuit to an incident signal to the antenna matching circuit.

Abstract: At least two antennas are selected from a plurality of antennas which consist of at least two antennas having polarization characteristics or directivities different from one another, and which are arranged such that spatial fading correlations between the antennas are low, and a multiple input multiple output communication is conducted by using the selected antennas.