Fujitsu Corporation

Katsuichi Ohara

Kanta Yamamoto

Masayuki Tanaka

Kazuo Takatsu

Yoshinori Nakamura

Hideo Abe

Toshiaki Hayashi

Toru Kosugi

Takahiro Furukawa

Akira Okawa

Akio Shinohara

Toshihito Echizenya

Kazuya Ikeda

Yuichi Hashimoto

Toshio Kanayama

Kouji Mizumoto

Hiroyuki Fukushima

Masanobu Miyamoto

Makoto Aoki

An optical transmission equipment having a switchover control function of optical transmission lines enables to reduce a required space in a common equipment supervision and control portion. The optical transmission equipment includes a pair of a work interface unit and a protection interface unit each accommodating an optical transmission line, and an add drop multiplexing unit for selecting an optical signal output from either of the interface unit pair. Each interface unit includes a switchover controller, and each of the interface unit pair is mutually connected via a communication path so as to share status information among the switchover controllers. Upon a failure in the work interface unit side of the interface unit pair, the failure is reported to the protection interface unit side prepared as an object for switchover, to send a switchover request from the protection interface unit side to the add drop multiplexing unit.

Optical transmission equipment

In a device for processing data signals, a storing part stores an input signal and the data signals included in the input signal are extracted from the storing part and the data signals are output at a desired output speed. Then, the data signal is output based on storage information of the input signal.

Device for processing data signals, method thereof, and device for multiplexing data signals

A network topology collection device determining a network topology which indicates a connection state of a route prepares opposed topology information which indicates the connection state between a collection node to which the network topology collection device itself belongs and opposed nodes which respectively terminate routes terminated by the collection node, collects opposed topology information of a node directly or indirectly routed to the collection node, and determines a topology of an entire network based on the opposed topology information collected. Also, in a hierarchized route, the collection device determines a network topology of a route in a specific hierarchy based on opposed topology information in the hierarchy and opposed topology information of a route in another hierarchy.

Network topology collection device

A data processing system having one or more processor modules and a plurality of shared memory busses to increase its total system performance. Processor modules send bus requests to a bus arbiter, when they attempt to make access to shared memories or memory-mapped peripheral control modules. When such memory access requests are received, the bus arbiter checks the availability of each bus that will be used to reach the requested memories, and send bus grant signals to the requesting processor modules after resolving conflicts, if any. Since the system provides separate paths to reach the individual shared memories, two or more processor modules can be granted their access requests at the same time.

Multiprocessor system with multiple memory buses for access to shared memories

A transmission device to which transmission lines over which signals including overhead information are transferred, includes a first part which gathers and transfers the overhead information of the signals transferred over the transmission lines to a second part, and the second part which terminates the overhead information of the signals.

Transmission device

A communications system has two transmission circuits, each transmitting a multiplexed signal in both ways. A repeating installation used therein selects either one of the two transmission circuits and terminates management information contained in a signal which flows through a transmission circuit selected by the selecting unit. The repeating installation sets the other non-selected transmission circuit to be in a high impedance state. The selection and termination are commonly performed for the two transmission circuits, and the repeating installation further extracts the management information transmitted and outputs the management information to be outputted. The management information includes a section overhead having management information concerning a repeating section of the communications system, and the repeating installation does not terminate management information concerning a multiplex section. One of the two transmission circuits includes a spare transmission circuit.

Repeating installation

An apparatus for connecting power sources to a plug-in unit has a plug-in connector and a plurality of connection control circuits. Terminal pins of the plug-in connector are connected simultaneously to a negative power source, a GND and a positive power source. When the negative power source and the GND are connected, a first connection control circuit is turned ON and connects the negative power source to a first load circuit. A second connection control circuit is turned on in response to an input from the negative power source supplied to the first load circuit, and supplies a GND signal to a third connection control circuit. The third connection control circuit is turned ON when the GND signal is supplied to the positive power source, and connects the positive power source to a second load circuit.

Apparatus for connecting power sources with plug-in unit

A method of controlling termination of current driven circuits that bidirectionally transmit and receive a current driven signal, has the step of transmitting the current driven signal from a first one of the current driven circuits and receiving the signal by a second one of at least one of the current driven circuits while connecting only a termination circuit on the receiver side and disconnecting the other termination circuits. Therefore, the method of controlling termination of current driven circuits carries out simple termination switching control to prevent a decrease in the impedance of the output stage of the current driven circuit and transmit the current driven signal at correct amplitude.

Method and apparatus for controlling termination of current driven

A path select switching unit is installed in network elements that are interconnected to make up a ring network. A path select switching unit has a path protection switched ring mode in which a first cross-connect uses a working path and a protection path which are counter-rotating paths set up on a line in the network. A re-use mode is also provided in which a second cross-connect is adapted for re-use of the protection path as a second working path for a different signal on that line. The path select switching unit in each network element detects a failure in the working path and, when a failure occurs, switches from the second cross-connect to the first cross-connect so as to force the path protection switched ring mode to be established, allowing data transmission over the protection path on the line.

Methods and apparatus for utilizing protection paths as additional

A digital cross connect system includes reception interface parts for converting an input line signal into a VT signal having a VT frame format in conformance with synchronous optical network (SONET) standards, a switching part for cross connecting the VT signal received from the reception interface parts, and transmission interface parts for converting the cross connected VT signal received from the switching parts into a line signal. The reception interface part inserts a frame synchronizing signal within a reserved path overhead part of the VT signal, and the transmission interface part achieves frame synchronization of the VT signal in response to the frame synchronizing signal.

Digital cross connect system

A cross connection apparatus which performs cross connection using divided VT signals, as cross connection units, obtained by division of the VT sizes foming virtual tributary (VT) signals of input side transmission line signals into whole integers by a predetermined common size unit, wherein it is possible to perform cross connection by common hardware even if a plurality of types of VT signals having different VT sizes are input.

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Yokohama, Japan

Katsuichi Ohara