Nippon Telegraph and Telephone Corporation

Masahiro Yokota

Hideki Maeda

Daisaku Shimazaki

Masaaki Inami

Masatoshi Namiki

Yoshiaki Yamada

Takuya Ohara

Kei Kitamura

Kaoru Arai

Katsuhiro Araya

Kengo Shintaku

Takashi Kotanigawa

Takafumi Hamano

Hiroto Takechi

Yuji Minato

Takuto Kimura

Yasutaka Sugano

Hiroki Kawahara

Taichi Kawano

Hiroshi Yamamoto

Kazumichi Sato

Kei Takeshita

Ken Nishimatsu

Arifumi Matsumoto

A transmission side transmission device includes: a first transmitter including a first switch; and a second transmitter including a second switch. A main signal is input to either the first transmitter or the second transmitter. The main signal input to the first transmitter is a first main signal and the main signal input to the second transmitter is a second main signal. The first transmitter and the second transmitter are configured such that, when the first transmitter detects a fault in the input first main signal: the second transmitter outputs the input second main signal to the first transmitter; and the first transmitter outputs the input second main signal via a first selector.

Transmission side transmission device and redundancy method of transmission side transmission device

A transmission side transmission device includes a first transmitter including a first switch and a second transmitter including a second switch. When the first transmitter detects a fault in the first main signal, the second transmitter outputs a duplicated signal of the second main signal to the first transmitter. The first selector of the first transmitter selects and outputs a duplicated signal of the input second main signal. When the second transmitter detects a fault in the first switch, the second transmitter selects and outputs the second main signal.

Transmitting side transmission device, receiving side transmission device, redundancy method of transmitting side transmission device, redundancy method of receiving side transmission device, program, and transmission device

The network device information management apparatus includes: a log data acquisition unit configured to acquire log data from each of the plurality of devices, the log data including information about components of the plurality of devices; and an inventory information estimation unit configured to exclude a common portion of the log data before and after registration of the component to extract a component configuration indicating information about the component newly registered to the device, compare the extracted component configuration with the component configuration extracted from a component registered to another device, estimate the common portion as inventory information, and store the estimated inventory information in storage means.

Network apparatus information management device and network apparatus information management method

A monitoring control unit () of an OXC () stores a management table () in which pieces of information regarding a modulation mode, an FEC, and a frame mode of an optical signal are associated with each other, and sequentially changes the modulation mode, the FEC, and the frame mode according to the management table () upon an LOS alert from a relay-side optical input/output unit () or an LOF alert from a DSP () being input thereto. Upon successfully receiving an appropriate optical signal according to the change, the monitoring control unit () acquires transmission source information included in the optical signal, and detects an occurrence of erroneous connection of an optical transmission line in an OXC (), which serves as a relay apparatus, when the acquired transmission source information indicates an optical cross-connect apparatus that is a transmission source different from an original transmission source.

Optical cross-connect device, optical transmission system, and optical transmission line connection error detection method

A transmission device () includes a flow table () that stores identification information about an uninterruptible target flow; a transmission-side identification unit () that identifies whether a received packet is from the target flow or a non-target flow based on whether the received packet matches the identification information about the target flow stored in the flow table (); a tag application unit () that applies, to packets from the target flow, an uninterruptible identifier indicating that the packets are from the target flow and a sequence number for distinguishing the packets from other packets; and a branch unit () that branches the packets from the target flow processed by the tag application unit () into packets to be transferred to an active path () among redundant routes and packets to be transferred to a backup path () among the redundant routes.

Transmitting device, receiving device, packet transfer system,packet transfer method, and packet transfer program

[Problem] A transmission system, an apparatus management server, a failure management method, and a program enabling the cause of a failure associated with a silent change of an article to be swiftly identified are provided. [Solution] An apparatus management serverof a transmission system includes a collection unit configured to collect history information on an introduction instance of articles to an optical transmission apparatusand an information analysis unitconfigured to visualize and display, based on the history information collected, a graph in which a starting date of use for each of the articles is associated with the number of introductions of the article.

Transmission system, device management server, fault management method, and program

A management device of a transmission system includes a new path information input unit, a statistical information collecting unit that collects statistical information of actual traffic from nodes, and an uninterruptible path designing unit that calculates a delay fluctuation in an entire path with respect to a fluctuation for each section of the path, and designs a path in which the calculated delay fluctuation is smaller than a maximum fluctuation amount according to a buffering amount in the reception node as an uninterruptible path, a path information setting unit that updates path information of the path and stores the updated path information in an existing path information storage unit, and sets a bandwidth permitted in a node constituting the path in the node, and a notification unit that notifies a user of a path that was not designed as the uninterruptible path.

Transmission system management device and transmission system design method

A delivery rate selection device, for selecting a delivery rate when delivering a video image from a video delivery server to a client in a video delivery service. When a delivery rate calculating unit receives from an inquiry source an inquiry of delivery rate for delivering a video image to a given user, a delivery rate calculating unit acquires presence or absence of a playback stall tolerance and presence or absence of an image quality deterioration tolerance of the given user from the user characteristic storage unit, selects an encoding rate from a plurality of encoding rates of the video image according to a combination of the presence or absence of a playback stall tolerance and the presence or absence of an image quality deterioration tolerance of the given user, and returns the selected encoding rate as the delivery rate to the inquiry source.

Delivery rate selection device, delivery rate selection method, and program

A pacing control device to perform pacing control on a content distributed from a content distribution device that performs streaming-based content distribution, includes an obtainer configured to obtain a communication quality threshold that corresponds to a communication environment in the pacing control device; and a controller configured not to make a request for the content to the content distribution device in a case where a communication quality in the pacing control device is lower than the communication quality threshold, and to make the request for the content to the content distribution device in a case where the communication quality is higher than the communication quality threshold.

Pacing control device, pacing control method, and program

In the optical transport system a transport frame generator divides a transport frame accommodating plural client signals into plural transmission signals. Subcarrier transmission units convert the signals into optical signals using different optical carriers and transmit the converted optical signals. Subcarrier reception units receive the transmitted optical signals and convert the optical signals into reception signals. A transport frame termination unit combines the reception signals to restore the transport frame. A time-demultiplexing processor time-demultiplexes the restored transport frame to be separated into the client signals. A time slot control unit determines a new time slot allocation when time-multiplexing the client signals in the transport frame and stops supply of electric power to a subcarrier transmission unit and a subcarrier reception unit that transmit and receive an optical signal to which the client signals are not allocated.

Optical transport system and resource optimization method

A framer in a transmission device allocates plural optical channel time slots to a plurality of logical prioritized paths. It allocates received client signals to the allocated time slots, and transmits the client signals by a plurality of optical subcarriers that use a plurality of optical wavelengths corresponding to the plurality of time slots. The framer includes: a time slot allocation unit that, in a case where an optical wavelength corresponding to a time slot allocated to a logical path having a high transmission priority is not used, allocates at least one of the plurality of time slots to the logical path having the high transmission priority while the time slot corresponding to the unused optical wavelength is avoided, to change the time slot allocated to the logical path having the high transmission priority.

Framer and framing method

A framer in a transmission device that allocates time slots of an optical channel to a logical path, divides client signals received via the logical path to the time slots allocated to the logical path, and transmits the client signals by a plurality of optical subcarriers using optical wavelengths correlated with the time slots includes: a time slot allocating unit configured to perform a process of reducing a transmission band of the logical path when some of the optical wavelengths are unavailable and changing the time slots allocated to the logical path depending on the reduced transmission band to avoid using the time slots corresponding to the unavailable optical wavelengths.

There is provided a tray which is connected to a plurality of transmitters that multicarrier-transmit a plurality of parallel signals by optical subcarriers. The framer selects time slots to be allocated to a path to be accommodated such that the number of optical subcarriers corresponding to the time slots satisfies a predetermined condition on the basis of empty time slots which are specified by path accommodation information indicating a correspondence between paths allocated to a client signal and time slots in a signal frame and the optical subcarriers corresponding to the empty time slots indicated by time slot information indicating a correspondence between the time slots and the optical subcarriers, and sets the selected time slot in the path accommodation information. The framer sets a client signal to the time slots on the basis of the path accommodation information.

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Tokyo, Japan

Masahiro Yokota