Fujitsu Corporation

Fujitsu Limied

Tatsuya Kikuzuki

Teruhisa Ninomiya

Ichirou Ida

Kazumi Kasai

Kaoru Yokoo

Masafumi Katoh

Hiroki Akano

Eiji Matsumoto

Akihiro Wada

Toshihiro Kunitake

Hiromasa Yamauchi

Makoto Yoshida

Yoji Ohashi

Makoto Hamaminato

Shiho Nakahara

Yuki Iwamasa

Iwamasa Yuki

Shuhei Ohsako

An information processing apparatus includes a memory, circuitry coupled to the memory, the circuitry configured to determine whether or not a binary search method is used by using a predetermined reference to determine the number of wireless access points, and search for a minimum number of access points satisfying communication requirements in a binary search loop in a case where it is determined that the binary search method is used and search for the minimum number of access points satisfying the communication requirements by decreasing the number of access points by a predetermined number of units at a time in a case where it is not determined that the binary search method is used to search for an arrangement of the wireless access points with respect to the searched minimum number of access points.

Information processing apparatus, arrangement computing method for wireless access points, and storage medium

There is provided a radio wave interference analysis apparatus configured to analyze a state of interference due to a plurality of interference signals of a plurality of interference sources on a target signal of a wireless device as an evaluation target at a reception point, the radio wave interference analysis apparatus including a memory, and a processor coupled to the memory and the processor configured to calculate a first probability of failure of reception of the target signal at the reception point due to collision of the target signal with an interference signal of the plurality of interference signals, calculate a second probability of failure of reception of the target signal at the reception point due to the interference signal of the plurality of interference sources, and output the first probability and the second probability.

Radio wave interference analysis apparatus, method, and medium

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.

Base station apparatus, wireless communication system and communication method

A non-transitory computer-readable recording medium storing a program that causes a computer to execute a procedure to determine a feature of each standard of a wireless environment in which radio signals including a CSS signal chirp-modulated co-exist, the procedure includes obtaining a spectrum by subjecting each radio signal to fast Fourier transform with predetermined frequency resolution and time resolution capable of visualizing a feature of the CSS signal, coarsening the frequency resolution of the spectrum by adopting an effective value in a specific frequency domain, calculating a duration of the radio signal, based on the coarsened frequency resolution of the spectrum, coarsening the time resolution of the spectrum by adopting an effective value in the duration, calculating a bandwidth of the radio signal, based on the coarsened time resolution of the spectrum, and determining the feature of the radio signal of each standard, based on the duration and the bandwidth.

Spectral analysis apparatus and spectral analysis method

A radio analyzer includes a memory configured to store a first reference signal, and a processor coupled to the memory and configured to calculate a first correlation value between a received wave and a non-modulated wave, calculate a second correlation value between the received wave and the first reference signal in a target section of the received wave, the first correlation value being smaller than a first threshold value in the target section, and detect a modulated wave from the received wave based on the second correlation value.

Radio analyzer and detecting method

There is provided a wireless analysis apparatus including: a memory unit configured to store information of electric power distribution indicating a temporal change of a frequency spectrum; and a computing unit configured to perform a procedure including: generating a plurality of divided regions having predetermined band widths by dividing the electric power distribution, calculating a temporal change amount of electric power with regard to each of the divided regions, detecting a rising portion and a falling portion of the electric power on the basis of the calculated temporal change amount, and identifying an individual signal component in the electric power distribution on the basis of the positions of the rising portion and the falling portion in the divided regions.

Wireless analysis apparatus and wireless analysis method

A base station apparatus that communicates with a radio communication terminal in a radio communication system, includes: processor configured to detect interference between the radio communication system and another radio communication system, and determine whether or not to switch a radio channel used to communicate with the radio communication terminal when the interference is detected; and a channel switching unit that switches the radio channel when the processor determines to switch the radio channel, and does not switch the radio channel when the processor determines not to switch the radio channel.

Base station apparatus, radio communication system, and communication method

An apparatus for assigning time slots refers to a hierarchical structure when a predetermined number of time slots in one of a plurality of communication cycles is assigned to a communication apparatus, identifies an associated frame whose use status is to be changed to used by the assignment of the predetermined number of time slots for a group managed in a layer corresponding to the requested communication cycle, and makes determination to assign a frame belonging to a group in which a number of time slots, in the associated frame, whose use status is changed to used is smaller, to the communication apparatus.

Apparatus and method for managing assignment of time slots

A radio analysis apparatus includes: a processor that calculates a modulation index of a radio signal generated by performing frequency shift keying on a baseband signal, based on phase shift amounts of the radio signal; and a memory that holds information in which bit patterns of the baseband signal are associated with correction values for correcting the phase shift amounts that have dropped by band limitation on the baseband signal. The processor restores the bit patterns of the baseband signal based on the phase shift amounts of the radio signal, corrects the phase shift amounts of the radio signal by using the correction values corresponding to the restored bit patterns, and calculates the modulation index based on the corrected phase shift amounts.

Radio analysis apparatus and method

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.

Wireless communication system, wireless communication method, transmission device, control method, and recording medium

A communication method for use in a communication system having a plurality of communication devices includes: a first communication device transmitting within a predefined period a connection request signal requesting a connection with another communication device; a second communication device transmitting a connection permit signal which contains the number of connection request signals received during the predefined period as the number of requesting candidates; the first communication device obtaining a transmission probability defining the probability of signal transmission such that the transmission probability decreases as the number of requesting candidates contained in the connection permit signal received from the second communication device increases; and the first communication device making a decision as to whether or not to transmit a signal out in accordance with the transmission probability at the timing that the signal can be transmitted to the second communication device.

Communication method, communication system, and communication device

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.

BAN system, terminal apparatus, BAN communications method, and computer product

A communication device includes a memory, and a processor coupled to the memory and configured to transmit a first packet including a first information within a contention-free period assigned to the communication device, the first packet storing last data to be transmitted in the contention-free period, the first information indicating presence of remaining data to be transmitted in the contention-free period, and, after transmit the first packet, to transmit a second packet including a second information within the contention-free period, the second information indicating absence of remaining data to be transmitted in the contention-free period.

Communication device and method for packet communications in a contention-free period

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.

Base station device, radio communication system, and base station device control method

A communication apparatus includes: a judgment section configured to judge a request for delay guarantee for data transmission; a route selection section configured to: select a first route including a mean delay time meeting a first condition, from routes available between the communication apparatus and a second communication apparatus which are in a network of wireless communication, when the request is a first request; and select a second route including a probability of successful data transmission for a given number of transmissions meeting a second condition, from the routes, when the request is a second request; and a transmission section configured to transmit the data to one of the first route and the second route.

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Sodegaura, Japan

Tatsuya Kikuzuki