Nippon Telegraph and Telephone Corporation

Ntt Broadband Platform, Inc.

Tomohiro Tokuyasu

Hayato Fukuzono

Tsutomu Tatsuta

Makoto Umeuchi

Toshihiro Manabe

Hiroyuki Furuya

Yu Ono

Takefumi Hiraguri

Tomohiro Nakayama

Keita Kuriyama

Kengo Nagata

Hiroshi Hojo

Tadao Kobayashi

A wireless communication system includes a plurality of sets of base station devices and terminal station devices configured to perform communications in an equal frame length using a time division duplex scheme, the communications of the plurality of sets being simultaneously operated in adjacent areas, in which each of the base station devices includes a control unit configured to control a transmission timing of a downlink signal transmitted from the base station device itself based on a communication distance between the base station device and the terminal station device of each of the sets or a reception timing of a downlink signal in the terminal station device such that reception timings of downlink signals transmitted from the base station device itself and other base station devices in the terminal station devices of the sets fall within a predetermined range determined in advance.

Wireless communication system, wireless communication method, management station device, base station device, and terminal station device

In a signal transmission system for transmitting an analog signal, in which a billing signal is superposed on an audio signal, from a transmitting device to a receiving device, the transmitting device includes a separation unit configured to separate the audio signal from the analog signal, an AD conversion unit configured to perform AD conversion on the audio signal separated by the separation unit, a detection unit configured to detect the billing signal from the analog signal, a coding unit configured to encode the billing signal detected by the detection unit, and a transmission unit configured to transmit the audio signal subjected to the AD conversion by the AD conversion unit and the billing signal encoded by the coding unit to the receiving device, and the receiving device includes a reception unit configured to receive the audio signal and the billing signal transmitted by the transmission unit, a DA conversion unit configured to perform DA conversion on the audio signal received by the reception unit, a decoding unit configured to decode the billing signal received by the reception unit, a conversion unit configured to convert the billing signal decoded by the decoding unit into an analog wave, and a combination unit configured to combine the audio signal subjected to the DA conversion by the DA conversion unit and the analog wave.

Signal transmission system and signal transmission method

Provided is a wireless communication system configured to accommodate a plurality of circuits to transmit a signal from a transmitter to a receiver, the system including a number-of-circuits observation unit configured to observe the number of circuits among the plurality of circuits through which communication is being performed; a quality observation unit configured to observe a quality of each of a plurality of communications; a determination unit configured to determine a modulation scheme for transmitting a signal based on the number of circuits observed by the number-of-circuits observation unit, the quality of each of the plurality of communications observed by the quality observation unit, and a required throughput of each of the plurality of circuits; and a modulation unit configured to modulate the signal using the modulation scheme determined by the determination unit.

Wireless communication system, wireless communication method, and wireless communication device

A wireless communication device includes an estimation observation unit that observes a channel condition by estimating a tendency of a long delay wave and a channel fluctuation from a received signal in which a training signal is added to a data frame, a first equalizer that compensates for the received signal, a second equalizer that compensates for the received signal with a property of having a higher long delay wave tolerance and a lower channel fluctuation tolerance than the first equalizer, and a control unit that performs control which switches such that the first equalizer or the second equalizer performs compensation for the received signal, on the basis of the channel condition observed by the estimation observation unit.

Wireless communication device, wireless communication system, and wireless communication method

An application to be booted is selected and operation of the application is controlled according to status of a link between an access point and a station. A station (STA) which can be connected to an access point (AP) includes a link information obtaining procedure which obtains link information including an identifier of the AP to which the STA is connected while the STA is connected to the AP and an application control procedure which selects an application to be booted according to the link information by referring to an action profile in which an identifier of the link information and an application to be booted are related and registered.

Station, station control method, and station control program

A probe request for an access point scan is transmitted over a specified radio channel according to an order of scanning, a connection candidate AP list including information indicating an access point which transmits a probe response and a received signal strength indication is generated when the probe response is received, the connection candidate AP list is referred to, one access point is selected from access points whose corresponding received signal strength indications exceed a predetermined threshold, connection processing is performed on the one access point being selected on the specified radio channel, and scanning is repeatedly performed by specifying a radio channel which is second in the order until scanning on all radio channels for which the order of scanning is set is completed when no probe response is received or the connection candidate AP list includes no received signal strength indication which exceeds the threshold.

Access point scan method, access point scan apparatus, and storage medium storing access point scan program

In an access point scan method by which a station disconnected from an access point scans for a next access point to which the station can be connected at a predetermined scan interval, the station sets a shorter scan interval when a possibility of connection to the next access point to which the station can be connected is presumed to be high or a need for connection is presumed to be great, and sets a longer scan interval when the possibility of connection is presumed to be low or the need for connection is presumed to be small, based on one of information on the access point to which the station being connected just before disconnection and information on the station.

Access point scan method, storage medium storing scan program, and station

A wireless relay device connecting a wireless terminal to one of a plurality of access networks with different wireless interfaces and performing relay processing between the wireless terminal and one of the plurality of access networks being connected, the wireless relay device including a wireless interface on local side to be connected to the wireless terminal, a plurality of wireless interfaces on network side to be connected to the plurality of respective access networks, and a connection control section which boots the plurality of wireless interfaces on network side when the wireless interface on local side receives a signal from the wireless terminal, connects a wireless interface on network side establishing a fastest connection and the wireless interface on local side, and connects the wireless terminal to an access network corresponding to the wireless interface on network side establishing the fastest connection.

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Yokosuka, Japan

Tomohiro Tokuyasu