Nippon Telegraph and Telephone Corporation

Ntt Electronics Corporation

Subaru Corporation

Kazutaka Hara

Ryota Shiina

Tomohiro Taniguchi

Tomoki Murakami

Toshiro Nakahira

Yasutaka Kimura

Atsuko Kawakita

Shinya Tamaki

Hiroyuki Furukawa

Kenji Horikawa

Satoshi Ikeda

Hirotaka Nakamura

Shunji Kimura

Koji Kitahara

Ryo Igarashi

Fumiyuki Moriya

Masamichi Fujiwara

Takuya Kanai

Masahiro Endo

Hirofumi Yabe

Takumi Hoshi

Yoshikazu Urabe

Tetsuya Suzuki

Atsushi Doki

Kazuaki Honda

Koji Tsuji

A radio terminal station device includes a communication unit, an information acquisition unit, a threshold calculation unit, a detection unit, and a system selection unit. The communication unit selects any one of a plurality of different communication systems and performs a radio communication. The information acquisition unit acquires information including a communication state of the radio terminal station device and at least communication states of other radio terminal station devices. The threshold calculation unit calculates a threshold value for detecting deterioration of the communication state of the radio terminal station device. The detection unit detects the deterioration of the communication state of a communication system used by the radio terminal station device. The system selection unit selects an optimal communication system from among the communication systems used by the other radio terminal station devices when the deterioration of the communication state of the communication system of the radio terminal station device is detected. Thus, it is possible to maintain favorable communication quality.

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

The present disclosure provides a monitoring system including an edge processing apparatus including a space distinct ID management database, a space distinct ID control unit, a storage unit, an analysis unit, and an abnormality determination unit, and a controller, a transmitter, and a camera with sensor that are installed in a location to be monitored, in which the space distinct ID management database stores a space distinct ID and a transmission time of the space distinct ID in association with the location to be monitored, the space distinct ID control unit acquires the space distinct ID associated with the location to be monitored from the space distinct ID management database and transmits the space distinct ID that is acquired to the controller in the associated location to be monitored, the controller transmits the space distinct ID acquired from the space distinct ID control unit to the transmitter, the transmitter generates a signal based on the space distinct ID acquired from the controller and diffuses, in a space of the location to be monitored, the signal that is generated, the camera with sensor includes a sensor that captures an image of the location to be monitored where the camera with sensor is installed and receives the signal diffused by the transmitter, and the camera with sensor transmits a received signal received by the sensor to the storage unit, the storage unit stores the received signal received from the camera with sensor in association with the location to be monitored where the camera with sensor is installed, the analysis unit extracts a space distinct ID from the received signal stored in the storage unit and transmits the space distinct ID that is extracted to the abnormality determination unit in association with the location to be monitored, and the abnormality determination unit compares and determines whether there is a match between the space distinct ID associated with the location to be monitored from the analysis unit and current time, and the space distinct ID and the transmission time of the space distinct ID associated with the location to be monitored that are stored in the space distinct ID management database.

Monitoring system, monitoring method, and monitoring program

An objective of the present invention is to provide an optical measurement device capable of performing remote optical measurement. An optical measurement device may include a light source that generates irradiation light with a beam shape, a beam control unit configured to control an irradiation direction of the irradiation light L, a condensing unit configured to condense returned light generated by irradiating a part of a measurement target with the irradiation light, and a detection unit configured to detect information regarding the measurement target included in the returned light condensed by the condensing unit. The beam control unit can control the irradiation direction of the irradiation light for measurement to any direction, and thus the condensing unit can efficiently receive the faint returned light from the measurement target.

Optical measuring device

An object is to provide a terminal device, a communication method, and a communication system which are capable of acquiring accurate optical ID information regardless of the position of the terminal device and the light receiving angle. The terminal device, the communication method, and the communication system according to the present invention each sets a threshold value for the illuminance of a received optical signal by using a moving average method, a weighted moving average method, or an exponential moving average, so that the optical signal can be binarized with a threshold value according to a change in the position of the terminal device, the light receiving angle, or the like. Information from other sensors may be used to set the threshold value.

Terminal devices, communication methods, and communication systems

In response to the above issue, an object of the present invention is to provide a diagnostic apparatus and a diagnostic method capable of accurately recognizing whether to use a long extension function at the time of relocation of an accommodation station of an OLT. The diagnostic apparatus according to an aspect of the present invention has an allowable line length list that is a relationship between a center wavelength and an allowable line distance that satisfies a selected spectrum width in an optical fiber used in an optical communication system, measures a center wavelength and a spectrum width of a spectrum for each ONU, matches the allowable line length list, and obtains an allowable line distance of each ONU.

Diagnostic device and diagnostic method

An object of the present invention is to provide a terminal device, a communication method, and a communication system which are capable of reducing the error rate even if the transmitting side and the receiving side are asynchronous. The terminal device, communication method, and communication system according to the present invention sample an optical signal more finely than a 0/1 bit pattern in optical ID estimation processing for determining which of 1/0 the data acquired by an optical sensor is, and perform a majority decision using a plurality of sampling values in a decision processing window. Thus, even if the correct sampling value fails to be obtained, the correct bit value can be derived from other samplings.

An object of the present disclosure is to make already installed smart lightings available as optical base stations as they are without modifying them, and perform connection/authentication control for RF communication using an optical signal sent out from the optical base stations. The present disclosure is a wireless communication system including: one or more wireless base stations that wirelessly communicate with a terminal; a base station control device that collects wireless base station information from each wireless base station, determines a wireless base station that wirelessly communicates with the terminal using the collected wireless base station information, and transmits an optical ID corresponding to the determined wireless base station; and one or more optical base stations that receive the optical ID from the base station control device, and transmit the received optical ID to the terminal using an optical signal, wherein the wireless base station determined by the base station control device wirelessly communicates with the terminal that receives the optical ID.

Wireless communication system, base station control device, evacuation guidance method, and base station control program

An object of the present disclosure is to inform a user of a safe evacuation guidance route in real time using smart lightings without deploying dedicated evacuation guidance facilities. The present disclosure is a wireless communication system including: one or more wireless base stations that wirelessly communicate with a terminal; a plurality of optical base stations that transmit an optical signal to the terminal; and a base station control device that controls the optical signal transmitted by the optical base stations, wherein the base station control device collects environment information around the optical base stations, detects a disaster around the optical base stations using the collected environment information, and when detecting a disaster, causes the optical base station installed at a position close to a disaster occurrence location and the optical base station installed at a position far from the disaster occurrence location to output light of different colors.

An objective is to provide a communication system, a terminal, a communication method, and a program capable of improving the probability of successful authentication regardless of mobility of the terminal. The communication system according to the present invention includes a terminalincluding: a sensor unitthat senses a state of the terminal and includes at least one of an acceleration sensor, a gyro sensor, a position sensor, and a proximity sensor; an optical receiverthat receives an optical modulation signal and outputs an electrical signal; a correction circuitthat corrects the electrical signal on a basis of the state of the terminal sensed by the sensor unitwhen one of the following is true: illuminance of light received from an optical transmitterby the optical receiveris equal to or lower than an illuminance threshold value; and a signal intensity of the electrical signal output by the optical receiveris equal to or lower than an intensity threshold value; an authentication information checking circuitthat checks the authentication information contained in the electrical signal; and a terminal-side RF transmitter/receiverthat transmits the authentication information to a base stationvia RF wireless communication.

Communication systems, terminals, communication methods, and programs

A control station device includes a policy generation unit that calculates a priority order of a plurality of wireless communication systems having different types of systems on a basis of information acquired from a wireless terminal device that selects one wireless communication system from among the plurality of wireless communication systems to perform wireless communication, and generates a selection policy indicating the priority order of the plurality of wireless communication systems, and a policy delivery unit that delivers the selection policy indicating the priority order of the plurality of wireless communication systems to the wireless terminal device. With this configuration, an optimal wireless communication system that maximizes the performance of each wireless terminal device can be selected while reducing the load and calculation time imposed on the control station device.

Control station device and wireless terminal station device

In order to solve the problems described above, an object of the present invention is to provide an optical communication system and a control method that automatically adjust a branching ratio of an optical splitter in accordance with a connection of a new ONU. An optical communication system according to the present invention causes an operation system or a DBA (Dynamic Bandwidth Allocation) function and a determining unit of a branching ratio of an optical splitter to cooperate with each other, adjusts the branching ratio so as to enable ranging with an active ONU, and takes into consideration an initial connection sequence through which an ONU is newly connected.

Optical communication system and control method

An object of the present invention is to provide an optical communication system and an optical communication method capable of achieving a long transmission distance with a passive element and obtaining redundancy of a ring topology. The optical communication system according to the present invention is a PON system having a ring configuration, in which an unequal branch optical splitter having a left-right symmetrical configuration is disposed in a trunk fiber wired in a loop shape. An OLT and an ONU have a configuration in which two sets of Tx (transmitter) and Rx (receiver) are mounted. Two sets of Tx (transmitters) and Rx (receivers) in each of a plurality of ONUs are respectively connected to left and right symmetrical ports of one unequally branched light beam SP.

Optical communication system and optical communication method

An objective is to provide a terminal device, a communication method, and a communication system in which the time taken by connection operations/authentication operations does not increase proportionally with the pattern length, even if the transmitting side and the receiving side are not synchronized. A terminal device, a communication method, and a communication system according to the present invention create n pieces of signal information (n-bit patterns) by sequentially shifting each bit of a single piece of received signal information (n-bit pattern) one bit at a time. Through the above, signal information time-shifted by one bit each is obtained. Thus, even if the transmitting side and the receiving side are not synchronized, one of the n pieces of signal information is a signal synchronized with the transmitting side. Thereafter, the signal synchronized with the transmitting side can be detected by a brute-force calculation with the patterns (ID information) in the list.

An object is to provide a communication system, a base station, and a communication method that can avoid a state in which an RF wireless communication cannot be started due to the quality of optical wireless communication. In an optical communication system according to the present invention, a base station device repeatedly transmits an authentication information frame addressed to a terminal device at a predetermined cycle by the optical wireless communication, the frame including authentication information for connection to the terminal device by the RF wireless communication. Even if the terminal fails to acquire the authentication information at a certain timing due to the quality of optical wireless communication, the communication system has a mechanism that acquires the same authentication information at regular time intervals, so that terminal authentication processing can be performed at the time when the terminal acquires the authentication information.

Communication systems, base stations, and communication methods

An optical communication system according to the present invention cancels waveform distortion due to wavelength dispersion by extracting the spectrum of a transmitted optical signal and passing the optical signal to a fiber having a dispersion value opposite to a dispersion amount corresponding to a transmission distance received by the spectrum component and compensates for a transmission path loss due to the fiber having the opposite dispersion value using optical splitters having different split ratios. With this configuration, the present invention can compensate for waveform distortion due to wavelength dispersion by a simple method in an access network and achieve an increase in the reachable transmission distance of the farthest user or an increase in the number of connectable users.

Growing community of inventors

Musashino, Japan

Kazutaka Hara