Nec Corporation

Takenaka Corporation

Kobe Steel, Ltd.

Nec C Orporation

Takatoshi Ogawa

Akira Fujishima

Kazuhito Hashimoto

Toshio Saito

Tamotsu Hasegawa

Yasuhiko Yoshioka

Nobuo Tsubouchi

Yoshimasa Ito

Tatsuya Yasunaga

Sadatoshi Ohno

Fumio Kamikubo

Takashi Kato

Atsumichi Kushibe

A time-synchronization system according to the present disclosure includes a relay apparatus () configured to perform time-synchronization with a master apparatus () through a transmission system of which a transmission delay changes depending on a transmission direction, and a relay apparatus () configured to perform time-synchronization with the relay apparatus (), in which the relay apparatus () transmits information about a difference between first time information obtained by performing time-synchronization with the relay apparatus () and second time information obtained from a time-synchronization source to the relay apparatus (), and the relay apparatus () corrects third time information obtained by performing time-synchronization with the master apparatus () by using the information about the difference, and performs time-synchronization with a slave apparatus () by using the corrected third time information.

Time-synchronization system, relay apparatus, time-synchronization method, and non-transitory computer readable medium

A radio transmission apparatus () includes: a radio communication unit () that performs radio communication by a first radio communication scheme; a radio communication unit () that performs radio communication by a second radio communication scheme; an abnormality determination unit () that determines whether an abnormality has occurred in the radio communication performed by the radio communication unit (); and a control unit () that controls transmission and reception of management information about the radio transmission apparatus () using the radio communication unit () or (). When an abnormality has occurred in the radio communication performed by the radio communication unit (), the control unit () performs control so that the management information is transmitted and received to and from a predetermined apparatus by using the radio communication unit ().

Radio transmission apparatus, transmission system, transmission method, and non-transitory computer readable medium storing program

An object is to provide a relay apparatus capable of detecting a failure that occurs in the relay apparatus. A relay apparatus () according to the present disclosure includes a data reception unit () configured to receive a synchronizing packet transmitted from a master apparatus (), the synchronizing packet containing a time value and a time correction value for correcting the time value, an update unit () configured to update the time correction value based on a processing time for the synchronizing packet, and a determination unit () configured to determine whether or not a failure has occurred in a functional block related to a process for updating the time correction value by using a result of a comparison between a corrected time value and a reference time value, the corrected time value having been corrected by using the updated time correction value.

Relay apparatus, communication system, and failure detection method

In order to simplify calculation of delay time lengths in a time synchronization device in a packet network, when executing time synchronization using a synchronization signal sent via the packet network, this time synchronization deviceincludes: a data receiving unitthat receives synchronization information including a time correction field used when correcting synchronization time information in a client device; a before-data-processing time correcting unitthat updates the time correction field by subtracting information indicating a time at which synchronization information is received, from the time correction field; an after-data-processing time correcting unitthat updates the time correction field by adding information indicating a time after performing data processing on the synchronization information, to the time correction information of the time correction field updated by the before-data-processing time correcting unit; and a data sending unitthat sends the updated synchronization information to the client device

Time synchronization device, time synchronization system, and time synchronization method

A communication apparatus () according to the present invention is provided with: a storage unit () that stored in advance difference information (), which is the difference between first time information (t) and second time information (t), said first time information (t) being received from a synchronization source communication apparatus () as a time synchronization source connected to a transmission system () wherein transmission delay time is different depending on the direction of transmission, and said second time information (t) obtained from a time synchronization origin () other than the transmission system (); and a time synchronization means () that carries out, when the second time information (t) cannot be obtained from the time synchronization origin (), time synchronization with the synchronization source communication apparatus () using the difference information () read out from the storage unit ().

Communication apparatus, time synchronization system, and time synchronization method

A synchronization apparatus capable of reducing the effect of the fluctuations in synchronization signals that are caused when the synchronization signals are received through a network are provided. A synchronization apparatus () according to the present invention receives a synchronization signal transmitted from a synchronization signal source () through a network. The synchronization apparatus () includes a frequency synchronization unit () that performs frequency synchronization based on a received synchronization signal, and outputs a frequency synchronization signal, a phase synchronization unit () that performs phase synchronization based on a synchronization signal transmitted from the synchronization signal source () through a network, and outputs a phase synchronization signal, and a phase synchronization control unit () that generates an offset value by using a phase difference between the frequency synchronization signal and the phase synchronization signal, and corrects a phase of the frequency synchronization signal by using the offset value.

Synchronization apparatus, synchronization system, radio communication apparatus and synchronization method

A first synchronization signal for synchronization with a synchronization signal source is acquired from a first signal source. A first signal synchronized with the synchronization signal source is generated based on the first synchronization signal. A second synchronization signal for synchronization with the synchronization signal source is acquired from a second signal source different from the first signal source. A second signal synchronized with the synchronization signal source is generated based on the second synchronization signal. A timing signal synchronized with the synchronization signal source is generated based on the first signal of a synchronization device. A phase difference between the timing signal and the second signal is output. An offset is set so that there is no phase difference between the timing signal and the second signal based on the phase difference.

Timing synchronization device and timing synchronization control method

Both a first profile that represents relationships between delay times premeasured over transmission paths and occurrence frequencies of the delay times and measurement periods of time for which the delay times over the transmission paths are measured are stored such that the first profile and the measurement period of time are correlated; a measurement period of time correlated with the first profile is obtained from the storage section if a second profile that represents relationships between delay times measured to obtain the measurement period of time and occurrence frequencies of the delay times is the same profile as the first profile; the delay times over the transmission paths are measured; and a mean value of the delay times measured for the measurement period of time is computed.

Setup of measurement period of time and method for setting

A transmitter transmits a ranging request message to a BS. A receiver receives response information in response to the ranging request message transmitted by the transmitter. A controller transmits the ranging request message from the transmitter at a transmission timing which has been previously set. Subsequently, if the receiver has not received the response information in response to the ranging request message within a predetermined period, the controller retransmits the ranging request message earlier than the transmission timing which has been previously set.

Subscriber station, time division multiplexing system and transmission timing control method suitable for wireless communication in synchronous PtoMP scheme

A metal material having a photocatalytic activity which comprises an anodized layer and a thin layer containing titanium oxide powder which are heat treated are sequentially laminated on the surface of a substrate comprising metal material including titanium. By anodically oxidizing the metal material including titanium, an anodized layer is formed on the surface thereof. A thin layer containing titanium oxide powder is further coated on this surface, and heat treatment is carried out before and/or after forming this thin layer containing titanium oxide powder.

Metal material having photocatalytic activity and method of

Architectural material using metal oxide exhibiting photocatalytic

A metal-oxide layer exhibiting a photocatalytic activity function is formed on the surface of an inorganic architectural material, such as external wall material, roofing material, internal wall material, flooring material, and ceiling material, including glass, tile, concrete, stone, metal, and the like, so as to provide the property of deodorizing a space coming in contact with the architectural material, and antimold, antisoiling properties, and ultraviolet-ray absorbency of the surface of the architectural material, as well as the long-term maintenance of these properties. Preferably, the metal-oxide layer is formed by fixing a metal-oxide thin film on the surface of the architectural material. Alternatively, the metal-oxide layer is formed as an architectural material in which the surface region includes an outer portion mainly formed of a metal mixture including a metal oxide, such as titanium oxide, and palladium for improving photocatalytic activity, or a metal mixture including a metal constituting the metal oxide, such as titanium, and a composite of a second metal, and an inner portion substantially formed of a metal mixture including titanium or a composite of titanium and palladium, the outer portion as well as the inner portion being formed continuously. As a method of manufacturing the latter architectural material, a metal mixture, i.e., an alloy, of titanium and a metal for improving photocatalytic activity, such as palladium, is fabricated, and after the alloy is processed into a desired shape, the processed alloy is subjected to oxidation treatment.

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Tokyo, Japan

Takatoshi Ogawa