Fujitsu Corporation

Hitachi, Ltd.

Nec Corporation

Nippon Telegraph and Telephone Corporation

Shigeo Amemiya

Kazuo Iguchi

Koji Tezuka

Tetsuo Soejima

Takao Ogura

Takafumi Chujo

Tomohiro Shinomiya

Hiroshi Takeo

Hiroaki Komine

Toshiaki Watanabe

Hiromi Ueda

Kazuo Murano

Yoshihiro Ashi

Yukio Nakano

Akihiko Takase

Naoaki Yamanaka

Yasuki Fujii

Michio Kusayanagi

Yoichi Sato

Ryuichi Ikematsu

Takatoshi Kurano

Yuichi Matsuda

Shigeo Shinada

Kenji Akutsu

Hitoshi Uematsu

Mituhiro Takano

Kazuhiko Hohara

Tetuhiro Okabe

Kiyoshi Saitou

A detour path determination method wherein each node on a determined detour path stores in advance first and second nodes upstream of each node as well as an identifier(s) of a packet directional path(s); a number of an identifier(s) of a packet directional path(s) required for switching in each link extending from a downstream node one node downstream of each node on the detour path are set for respective nodes on the detour path beginning from the terminal node upstream; the identifier(s) of the packet directional path(s) set as above, and an identifier(s) of a corresponding packet directional path(s) at a start node of the detour path, are sent to a node one node upstream of the above each node; the start node updates a identification data table at the node, by an identifier(s) of a packet directional path(s) set downstream of the start node based on the corresponding identifier(s) of packet directional path(s) at a start node of the detour path, when the start node receives the above identifier(s) (FIG. 1).

Detour path determination method

An alarm masking system is provided which is capable of implementing alarm priority processing or alarm inhibit processing in ATM transmission equipment. In ATM transmission equipment, a received virtual path or virtual channel is switched by means of a switching unit and then sent to an interface unit. In doing this, if a higher priority alarm is detected or received at a reception side interface unit, an intra-office tag is added to the alarm cell and then it is output, so that by detecting this intra-office tag it is possible to inhibit generation of lower priority alarms in response to the higher order alarm.

System for achieving alarm masking processing

A packet directional path identifier transfer system contains on the transmission side thereof, a means 2 of converting packet directional path identifier data into bit map information in which an address of each bit corresponds to a packet directional path identifier. The system contains on the reception side thereof, a means 5 for inversely converting the bit map information of the packet directional path identifier data to the packet directional path identifier data. Otherwise, the system further contains on the transmission side thereof, means 8 and 10 for determining the top and bottom values of the packet directional path identifier data to be transmitted, and a means 9 for converting the packet directional path identifier data between the top and bottom values into bit map information, and at the reception side thereof, a means 13 for inversely converting into the initial packet directional path identifier data the bit map information of the packet directional path identifier between the top and bottom values. Further, the top value of the identifier(s) of the newly-set packet directional path(s) determined from the non-used packet directional path identifier(s) in the outgoing packet directional path of the transmission-side node and the number of the newly-set packet directional path identifier(s) are transmitted, and a reference is made to the incoming packet directional path identifier table at the reception-side node to recognize the newly-set packet directional path(s) based on the information received. (FIGS. 1 and 2.)

Packet directional path identifier transfer system

A method for restoring a communication failure in a network comprises the steps of providing a predetermined order for selection of the links included in the network, searching for an alternative communication path upon a failure in communication occurring in the network, producing, at a first arbitrary node included in the alternative communication path, a first path setup message containing at least information about the number of the paths to be selected in a first link extending from the first node for setting up the alternative communication path, and an identification code of the path that is to be selected at first in the first link for establishing the alternative communication path, transmitting the first path setup message to a second node also included in the alternative communication path and connected to the first node by a second link, for affecting a setup of the connection therein. The second node selects paths with the number specified by the path setup message according to said predetermined order of selection and affects a connection to the paths in the first link according to the order of selection.

Distributed control of telecommunication network for setting up an

Multiple access system for communication network

A UPC circuit fault diagnosis system for diagnosing a failure in a UPC circuit controls cell traffic volume on the basis of prescribed information about cell traffic. Failure diagnosis of a UPC circuit is provided by a usage parameter determination of at least one kind of cell, using more than one system and comparing determination results. The diagnosis system has an operating UPC circuit for controlling a total of m kinds of cells, and a standby UPC circuit for controlling a total of n kinds of cells. The system also has a total of q bridge memories for keeping a chronological record of the prescribed information of arriving cells. A fault diagnosis of the bridge memories is provided by comparing the contents of the bridge memories, using more than one system.

Trouble diagnosis system of UPC circuit

In an ATM switching network, ATM (asynchronous transfer mode) self-routing switches are interconnected by facilities carrying STM-N (synchronous transport modules level N) signals. At each inlet of an ATM self-routing switch, an STM overhead is removed from each frame of an incoming STM-N signal to create a vacant interval and the frame is converted according to ATM cell format into a series of data ATM cells, and an idle ATM cell is derived from the vacant interval. A supervisory bit sequence is inserted to the payload field of the idle ATM cell to produce a supervisory ATM cell, and the data and supervisory ATM cells are sent into the ATM switch. At each outlet of the switch, the bit sequence of the supervisory ATM cell is checked to evaluate the quality of the ATM switch and a series of data ATM cells is then converted into an STM-N signal according to STM-N frame format.

High throughput supervisory system for ATM switching systems

Inter-network connecting system

A communication system containing a master station and a plurality of slave stations. The master station receives a request from one of the plurality of slave stations and memorizes one or more requests from one or more slave stations. The master station also sends a request sending allowance signal which addresses one of the plurality of slave stations to give an allowance to send a request for sending data, and sends a data sending allowance signal which addresses one of the plurality of slave stations to give an allowance to send data, according to a request which is memorized. Each of the slave stations detects a request sending allowance signal which addresses its own slave station, and a data sending allowance signal which addresses its own slave station. Each of the slave stations also sends a request for sending data to the master station when its own slave station detects a request sending allowance signal which addresses its own slave station. In addition, each slave station sends data to the master station when its own slave station detects a data sending allowance signal which addresses its own slave station.

Communication system carrying out polling for request and data

A communication system including a master station, a plurality of slave stations each for communicating with the master station, a two-way transmission line connecting the master station and the plurality of slave stations. Each of the slave stations sends a request for further communication with the master station, to the master station when its own slave station is allowed to communicate with the master station and its own slave station has the above request. The master station detects the request for further communication with the master station in a signal sent from a slave station, and memorizes the slave station from which the request for further communication with the master station is detected, until an allowance signal is sent to the slave station from the master station corresponding to the memorizing of the slave station. The master station has a cyclic address pointer which points to an address of a next one of the slave stations in a cyclic order when no slave station is memorized in the master station. The master station outputs the allowance signal to communicate with the master station to a slave station which is memorized in the master station or to a slave station the address of which is pointed to by the cyclic address pointer when no request is memorized in the master station.

Polling communication system with priority control

A coded transmission system wherein each bit of transmitted data having a logical value is coded depending on a coded result of a preceding bit. The coded transmission system contains a sender-side apparatus, a transmission line, and a receiver-side apparatus. In the sender-side apparatus, a resetting bit and a message are generated; a code of a bit last transmitted which is necessary to code a bit which is to be transmitted next is memorized in a first preceding code memorizing circuit; and the content of the first preceding code memorizing circuit is reset to an initial code responding to the resetting bit. A coding circuit receives the resetting bit and the message, codes each bit of the message in accordance with a predetermined coding rule and the content of the first preceding code memorizing circuit, and codes the resetting bit to a predetermined resetting code which is different from the codes used in the coding of the message. In the receiver-side apparatus, a code of a bit last received which is necessary to decode a code of a bit which is received next is memorized in a second preceding code memorizing circuit. A resetting circuit resets a content of a second preceding code memorizing circuit to a predetermined initial code when receiving the resetting code. A decoding circuit decodes the received codes corresponding to the message in accordance with the predetermined coding rule and the content of the second preceding code memorizing circuit.

Coded transmission system with initializing code

A circuit which operates at the fixed timing and discriminates the control signal is provided and the timing pulse for demultiplexing is controlled in accordance with the discriminated control signal in the receiving part of the synchronized multiplexing system in which the basic signals are generated by inserting the control signal required for multiplexing on the frame structure of basic signal rate and the high level multiplexing signal is formed by multiplexing such basic signals, thereby stable correspondence between the channel at the time of multiplexing in the sending side and the channel after the demultiplexing in the receiving side can be ensured.

Demultiplexing device of synchronous multiplexing system

In a sequential polling type communication network system including a master station, a first channel, a second channel, and at least two slave stations, the master station includes request registration units for registering data transmission requests from slave stations during a data transmission by another slave station, and an interrupt polling unit for polling the slave station which has issued the data transmission request after completion of the data transmission or completion of a polling of a slave station, and the slave station includes a unit for responding to a polling during the data transmission, and transitting a data transmission request when data to be transmitted exists, and for responding to the interrupt polling from the master station, and transmitting the data to the master station until the data transmission is completed.

Polling network communication system having transmission request

Disclosed is a frame synchronizing apparatus in a receiving equipment for receiving digital signals for PCM communication. The digital signals consists serial signals at a rate of f.sub.0 (bps). The serial signals include a frame synchronizing signal consituting n bits or a part of the frame synchronizing signal, collectively arranged in one frame. To attain a high-speed operation and a shorter synchronization establishing time, the apparatus comprises a latching circuit for converting the serial signals into parallel signals and for latching the parallel signals, and a circuit for detecting a plural number of times of synchronization during the n bit interval in one frame.

Frame synchronizing apparatus

An optical bus type communication system comprises a bus type transmission line consisting of an optical fiber, a light source provided at the one end of the bus type transmission line for sending an optical signal having a constant level to the bus type transmission line, a plurality of optical switches mounted on the bus type transmission line, and a plurality of terminal interfaces. Each terminal interface sends data by switching the corresponding optical switch so that the optical signals on the transmission line are modulated with the data.

Growing community of inventors

Yokohama, Japan

Shigeo Amemiya