Abstract: A method to estimate, in a communication system that includes a first communication device that executes a service, a second communication device that communicates with the first communication device via a network, and a monitoring device that monitors the network, quality of the service executed by the first communication device, includes obtaining a packet transmitted in a predetermined direction over the network, classifying the obtained packet into a packet of a first type and a packet of a second type different from the packet of the first type, and determining a feature for each type of the classified packet, and estimating the quality of the service executed by the first communication device by using a training model trained by using the feature and the quality of the service at timing when the packet used to determine the feature is transmitted, by processor circuitry.

Abstract: A device stores relationship information that indicates a correspondence relationship between a received signal strength indicator at a time of reception of a signal from a wireless transmission path and an available bandwidth of data transmission in the wireless transmission path; acquires a measurement value of the received signal strength indicator during communication with an image transmission device that transmits image data via a communication path; estimates a first available bandwidth in the wireless transmission path based on the measurement value and the relationship information; generates control information for adjustment of a transmission rate of image data in the image transmission device based on the first available bandwidth; transmits the control information to the image transmission device; measure a second available bandwidth in the wireless transmission path; and optimizes the correspondence relationship based on a comparison result between the first available bandwidth and the second ava

Abstract: A non-transitory computer-readable recording medium storing a transmission program causing a computer of a first transmission apparatus to execute a procedure, the procedure includes detecting a collision between a transmission timing of an intra-coded video frame in first video data transmitted from the first transmission apparatus and a transmission timing of an intra-coded video frame in second video data transmitted from a second transmission apparatus, changing, when the collision is detected at a first time, a frame type of the first video data to one of a forward predictive coded video frame and a bi-directional predictive coded video frame, and transmitting the first video data of which the frame type is changed, at a second time at which the intra-coded video frame in the first video data is scheduled to be transmitted.

Abstract: An information processing apparatus includes a memory, and a processor coupled to the memory and configured to obtain location information indicating locations of a wireless transmitter and a wireless receiver, simulate a first power of a first reception signal at the wireless receiver in a condition that a radio signal is transmitted from the wireless transmitter, identify a first probability distribution model in accordance with the first reception signal, identify a first parameter of the first probability distribution model in accordance with the first power and a propagation environment defined by the locations of the wireless transmitter and the wireless receiver indicated by the location information, and based on the first probability distribution model using the first parameter, simulate a second power of a second reception signal at around the wireless receiver.

Abstract: An information processing apparatus includes a memory, and a processor coupled to the memory and configured to obtain location information indicating locations of a wireless transmitter and a wireless receiver, simulate a first power of a first reception signal at the wireless receiver in a condition that a radio signal is transmitted from the wireless transmitter, identify a first probability distribution model in accordance with the first reception signal, identify a first parameter of the first probability distribution model in accordance with the first power and a propagation environment defined by the locations of the wireless transmitter and the wireless receiver indicated by the location information, and based on the first probability distribution model using the first parameter, simulate a second power of a second reception signal at around the wireless receiver.

Abstract: A wireless communication apparatus includes antenna elements, each receiving a first signal and a second signal, a first estimator that estimates first channel information of the first signal, a false signal generator that generates false signals that are equal in number to or greater in number than the number of the antenna elements, each of the false signals arriving from a unique direction that is different from a direction of arrival of the first signal, a weight generator that generates first weights, each being associated with a corresponding one of the false signals and forming a null in the direction of arrival of the first signal, a multiplier that multiplies a signals received by the respective antenna elements by the first weights to acquire weight-multiplied signals, and a second estimator that estimates second channel information of the second signal using the weight-multiplied signals.

Abstract: A radio communication device includes: a receiver configured to receive a radio signal; and a processor coupled to the receiver, configured to switch between a first communication mode and a second communication mode in accordance with scheduling of allocation of a time slot to another radio communication device based on the radio signal, communication between the radio communication device and the another radio communication device being executed using time division multiplexing in the first communication mode, and communication between the radio communication device and the another radio communication device being executed using a competitive access method in the second communication mode.

Abstract: A receiving device includes a receiving circuit configured to receive a first packet and a second packet, each of the first packet and the second packet including a first signal in a head and a second signal in a tail, respectively, and a processor configured to detect a collision of the first packet and the second packet based on a receiving timing of the first signal of the first packet, a receiving timing of the second signal of the first packet, and at least one of a receiving timing of the first signal of the second packet and a receiving timing of the second signal of the second packet, after detecting the collision, separate the first packet and the second packet based on the first signal of the first packet and the second signal of the second packet, and demodulate the separated first packet and the separated second packet, respectively.

Abstract: A wireless communication apparatus includes antenna elements, each receiving a first signal and a second signal, a first estimator that estimates first channel information of the first signal, a false signal generator that generates false signals that are equal in number to or greater in number than the number of the antenna elements, each of the false signals arriving from a unique direction that is different from a direction of arrival of the first signal, a weight generator that generates first weights, each being associated with a corresponding one of the false signals and forming a null in the direction of arrival of the first signal, a multiplier that multiplies a signals received by the respective antenna elements by the first weights to acquire weight-multiplied signals, and a second estimator that estimates second channel information of the second signal using the weight-multiplied signals.

Abstract: A calculation unit computes, based on subsequent information that is added to data transmitted from a terminal device and indicates the presence or absence of untransmitted data reserved in the terminal device when transmitting the data, the number of data in which untransmitted data exists among the certain number of data previously transmitted from the terminal device. A time slot assignment control unit controls the assigned size of a time slot to the terminal device based on the number of the data, in which untransmitted data exists, computed by the calculation unit. A data processing unit notifies the terminal device of the assigned size of the time slot determined by the time slot assignment control unit.

Abstract: A biological sensing system includes a biological information detector that is placed in a first specified portion of a living thing, and detects biological information of the living thing; a position displacement detector that detects an amount of a displacement of a position of the biological information detector from the first portion when the biological information is detected; and a processor that executes a process including estimating optimum biological information from the biological information detected by the biological information detector in accordance with the amount of the displacement.

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 system that includes a hub and multiple nodes is provided. The nodes include a wireless communication control unit that acquires, during a predetermined communication time period, a signal transmitted to the hub by a node; an RSSI calculating unit that calculates propagation information from the signal acquired by the wireless communication control unit; and an RSSI table creating unit that transmits the calculated propagation information to the hub. The hub includes a wireless communication control unit that receives propagation information transmitted by each of the nodes and an RSSI table aggregating unit that aggregates the received propagation information.

Abstract: A wireless communication device, including a radio transceiver data configured to transmit and to receive data packets to and from a base station, and a processor configured to compute a proportional hidden standby time being computed on the basis of at least two of from among a proportional exposed communication time, a proportional exposed collision time, and a proportional exposed standby time, to compute a predicted PER from the proportional hidden standby time computed; to compute a threshold value for the number of retransmission attempts on the basis of the predicted PER computed, and to cause the radio transceiver to repeat transmission of a data packet to the base station until the number of transmissions exceeds the threshold value computed in the case of failed transmission of a data packet to the base station by the radio transceiver.

Abstract: A mobile communication terminal used in a mobile communication system providing mobile communicating service in a first frequency band is disclosed. The mobile communication terminal comprises a first signal processing circuit for processing signals for the mobile communication service; a second signal processing circuit for processing signals for radio tag communicating in a second frequency band; and an antenna commonly used by the first and second signal processing circuits. The impedance of the antenna is matched with the first signal processing circuit in the first frequency band and matched with the second signal processing circuit in the second frequency band.

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 radio communication device includes: a receiver configured to receive a radio signal; and a processor coupled to the receiver, configured to switch between a first communication mode and a second communication mode in accordance with scheduling of allocation of a time slot to another radio communication device based on the radio signal, communication between the radio communication device and the another radio communication device being executed using time division multiplexing in the first communication mode, and communication between the radio communication device and the another radio communication device being executed using a competitive access method in the second communication mode.

Abstract: A calculation unit computes, based on subsequent information that is added to data transmitted from a terminal device and indicates the presence or absence of untransmitted data reserved in the terminal device when transmitting the data, the number of data in which untransmitted data exists among the certain number of data previously transmitted from the terminal device. A time slot assignment control unit controls the assigned size of a time slot to the terminal device based on the number of the data, in which untransmitted data exists, computed by the calculation unit. A data processing unit notifies the terminal device of the assigned size of the time slot determined by the time slot assignment control unit.

Abstract: An IQ imbalance correction method includes transmitting a plurality of pairs of RF training signals in installments by pairing RF training signals symmetric with respect to a center frequency on a frequency axis; setting a reception local frequency to change to a frequency that is suitable to receive, via an internal path, each of the plurality of pairs of RF training signals transmitted in installments, and suitable to convert the each of the plurality of pairs of RF training signals into IF training signals; and performing quadrature demodulation on the IF training signals, respectively, in a digital circuit area to generate BB training signals.

Abstract: A wireless communication system that includes a hub and multiple nodes is provided. The nodes include a wireless communication control unit that acquires, during a predetermined communication time period, a signal transmitted to the hub by a node; an RSSI calculating unit that calculates propagation information from the signal acquired by the wireless communication control unit; and an RSSI table creating unit that transmits the calculated propagation information to the hub. The hub includes a wireless communication control unit that receives propagation information transmitted by each of the nodes and an RSSI table aggregating unit that aggregates the received propagation information.