Fujitsu Corporation

Mikio Nakayama

Miyuki Kawataka

Satoshi Kakuma

Yoshihiro Uchida

Yuzo Okuyama

Yoshihiro Watanabe

Yoshiharu Kato

Shiro Uriu

Masami Murayama

Tetsuo Tachibana

Takashi Hatano

Kenichi Okabe

Jun Itoh

Yasuhiro Aso

Jyoei Kamoi

Jin Abe

Naoyuki Izawa

Eiji Ishioka

Hiroshi Nishida

Noriko Samejima

Shigeru Sekine

Satoshi Esaka

Yoshiyuki Karakawa

Fumio Hirase

Yasuhiro Nishikawa

Shinichi Araya

Youzou Iketani

Nobuyuki Tsutsui

Hiromi Yamanaka

Yoshihisa Tsuruta

Kazuhito Yasue

Atsushi Kagawa

Atsuko Suzuki

Shouji Kohira

Koji Ikeda

Takashi Nara

Naoki Aihara

Shigehiko Yazawa

Tomoyuki Yamaguchi

Haruo Moritomo

Toru Ogawa

Yutaka Isonuma

Yasusi Kobayasi

Kazuhiko Kumagai

Takayuki Takeda

Naoya Matsumura

Yoshiaki Suya

Satoshi Makuma

Yasusi Kobayashi

A switch station including an ATM switch; a memory storing control data for operations of the switch station; an intra-station device, accommodating a subscriber line, performing communication operation on subscriber ATM cell; a control processor generating control information in link access protocol (LAP) format; and an interface unit converting LAP control information into ATM cell to the intra-station device through the ATM switch, wherein the control information is communicated according to LAP, the intra-station device receives the control information and transmits a direct memory access request to obtain control data stored in the memory, the interface unit obtains and converts the data format of the control data into ATM cell to transmit to the intra-station device through the switch, and the intra-station device performs the communication operation on the subscriber ATM cell based on the control data received through the switch.

Intra-station control system for connectionless communications system

The present invention is intended to prevent from billing an unnecessary charge to an user by omitting AIS signals transmitted/received between a transmission side ATM unit and a receiving side ATM unit when a loss of service occurs in a communication network in which existing communication lines are connected by an ATM communication unit. In order to achieve the aforementioned goal, the transmission side ATM unit is adapted to monitor a signal received from a communication line on the transmission side and to stop the transmission of ATM cells to the receiving side ATM unit for a certain period of time when it detects an AIS signal indicating a loss of service on the transmission side and the receiving side ATM unit is adapted to monitor a state for receiving the ATM cells transmitted from the transmission side ATM unit and when it recognizes that the receiving of the ATM cells is stopped for a certain period of time, to generate an AIS signal indicating the loss of service on the transmission side and to send it on the communication line on the receiving side.

AIS transmission method in ATM communication system, transmission side ATM unit and ATM communication system

A system for controlling a bandwidth when receiving and reassembling a consecutive data stream transferred while segmented by AAL1 format cells which enables correct determination of non-P and P formats and reassembly of cells even when error arises in multiple bits including the CSI bit of an AAL1 cell or when adding dummy cells and thereby enabling prevention of a gap in data in a frame, comprising, in a data reassembly unit which reassembles received cells, an 8-cell buffer for storing 8 cells of a cycle of a sequence count (SC) of 0 to 7 and sending the cells out to a later stage after a check unit of a sequence number (SN) field confirms normalcy of the cells and a control unit for control so that the number of P format cells stored in the 8-cell buffer becomes 1 cell when 8 cells are stored in the 8-cell buffer.

System for controlling AAL1 cell bandwidth

The present invention relates to a line module protection method and a device utilizing that method. According to the line module protection method of the present invention, line module protection is performed by switching the connection from a broken line accommodating module to an auxiliary module. A plurality of line accommodating modules are included in a line accommodating unit connected to the lines in a network. The plurality of line accommodating modules are divided into a plurality of groups, and the auxiliary module is placed substantially at the same distance from all the groups. Thus, a large number of line accommodating modules for performing line module protection can be employed with one auxiliary module.

Line module protection method and device utilizing said method

The invention provides a fixed length cell handling image communication method wherein moving picture data are compressed to data having a fixed transmission rate using a compression method for still pictures and then converted into fixed length cells so that image processing such as compression/decompression of the moving picture data can be performed at a high rate while keeping a high compression ratio and a high picture quality. A transmission apparatus for use with the method includes an image data compression section for performing still picture compression processing for moving picture data, which define information of a plurality of screens individually divided into a plurality of fields to be successively transmitted per unit time, in response to field timing information representative of a compression timing of each field to convert the moving picture data into variable length data which are independent of each other, a transmission buffer section for converting the variable length data into fixed length data having a fixed transmission rate, and a fixed length cell transmission section for placing the fixed length data and the field timing information into data parts of fixed length cells and transmitting the fixed length cells.

FIXED LENGTH CELL HANDLING TYPE IMAGE COMMUNICATION METHOD AS WELL AS TRANSMISSION APPARATUS FOR FIXED LENGTH CELL HANDLING TYPE IMAGE COMMUNICATION AND RECEPTION APPARATUS FOR FIXED LENGTH CELL HANDLING TYPE IMAGE COMMUNICATION

The quality and performance of the connectionless communications system are improved. When a BOM is received, the destination address DA of the L3-PDU stored in the payload of the BOM is retrieved, and the tag information is obtained from the DA (S,). The output message identifier MID is reserved (S,), and the tag information and output MID are assigned to the BOM (S,). Then, the tag information and output MID are written to the table. When a COM is received, the tag information and output MID are retrieved using the MID of the COM as a key, and the information is provided for the COM (S,and S,). When an EOM is received, the tag information and output MID are retrieved using the MID of the EOM as a key, and the information is provided for the EOM (S,and S,). Then, the output MID is released (S,).

Connectionless communications system, its test method, and intra-station control system

A processing apparatus for measuring accumulated values of performance monitoring (PM) parameters concerning a reception signal received by a transmission device, which is capable of detecting upper layer failures in a more accurate, hardware-based way, without increasing the workload imposed on the system's firmware. PM parameters represent the statistics of events that meet prescribed criteria for defects and anomalies in the reception signal. The processing apparatus has a plurality of failure detection units to detect different kinds of failures in the reception signal and produce failure detection signals corresponding thereto. Those failure detection units include a first failure detection unit that detects a first kind of failure and a second failure detection unit that detects a second kind of failure. On the basis of the failure detection signals, a PM controller detects at least one kind of PM parameter, and a counter unit accumulates the detected PM parameter. A control signal generator produces a stop command signal that is activated while at least the second kind of failure is present. This stop command signal is supplied to the first failure detection unit to inhibit its operation and stop the detection of the first kind of failure.

Processing apparatus for measuring performance monitoring parameters

A transmitting device cyclically distributes a plurality of cells to a plurality of lines in a predetermined order. The transmitting unit loads the same cell block number into the cells to be distributed to the lines in the same cycle, and transmits the cells to the lines. A receiving device, whenever receiving the cells from the transmitting device via the lines, arranges the cells into which the same cell block number is loaded in the predetermined order.

Network system, transmitting device and receiving device

A plurality of input lines are respectively connected to separate multiplexing units that are connected in cascade by cascading lines. Select signals are transferred in parallel with fixed length packets over the cascading lines. Each separate multiplexing unit is responsive to a select signal received from the cascading line to select one of fixed length packets received over the corresponding input line and the upstream cascading line and output it over the downstream cascading line. The most downstream separate multiplexing unit provides a multiplexed output of the input lines.

Line multiplexing system

In cell transfer in which cells are sent at uniform intervals, in a case in which 18 cells have been lost between cell A (SN=2) and cell B (SN=5), every time 8 times the expectation value T of the cell arrival interval elapses after the arrival of cell A a dummy cell having the same sequence number as cell A (SN=2) is written into the cell FIFO section. Cells or dummy cells are stored in the cell FIFO section in the order SN=2, 2, 2, 5. When cells or dummy cells are read out of the cell FIFO section in order, if the sequence number SN=2 appears twice in a row, dummy data are created corresponding to the cells SN=3, 4, 5, 6, 7, 0, 1; if the sequence number SN=2 is followed by SN=5, then dummy data are created corresponding to SN=3 and 4.

Buffer control system

An apparatus for absorbing an arrival time delay of a fixed length packet, equipped with a first-in, first-out type memory, a fixed length packet writing unit for reading out information stored within fixed length packet and for writing into the first-in, first-out type memory, a first-cell detection unit for detecting the fixed length packet which is first received, a read-out timing generation unit for, in the case where the first-received fixed length packet has been detected with the first cell detection unit, generating read-out timing that shows read-out initiation following a prescribed time lapse, and a read-out unit for, in the case where read-out timing has been generated with the read-out timing generation unit, initiating the read-out of information stored within the first-in, first-out type memory.

Apparatus and method for absorbing an arrival time delay fluctuation of

An internal timing information producing portion produces internal timing information IRTS1 to IRTS4 which is the timing information on a data reception clock by using a network clock C.sub.N and the data reception clock C.sub.RU. A calculator calculates the difference between the internal timing information IRTS1 to IRTS4 and the transmission timing information RRTS1 to RRTS4 contained in a received cell, and a data reception clock producing portion adjusts the timing of the data reception clock C.sub.RU so that the difference is zero and outputs the adjusted timing. An ATM cell decomposing portion outputs the user data D.sub.RU in synchronism with the data reception clock C.sub.RU which is input from the data reception clock producing portion.

Interface device

A cordless telephone set includes a battery, and a communications part for communicating with another cordless telephone set via a transmission medium including radio channels, the communications part comprising a part which detects a call received via the transmission medium and indicates receipt of the call. A D.C. signal detection unit detects a D.C. signal supplied from a battery charger when a battery is coupled to the battery charger and charged thereby. A power supply line setting unit, which is coupled to the part of the communications part and the D.C. signal detection unit, establishes a power supply line for supplying electricity generated by the battery charger to the part of the communications part when the D.C. signal detection unit detects the D.C. signal.

Cordless telephone set with a battery and a battery charger and having a

Interface device between a network and an exchange for assembling

In an ATM communication system, in order to prevent a user from an unnecessary charge due to omitting AIS (Alarm Indication Signal) transmitted/received between a transmission side ATM unit and a receiving side ATM unit when a loss of service occurs in a communication network in which existing communication lines are connected by an ATM communication unit, the transmission side ATM unit is configured to monitor a signal received from a communication line on the transmission side and to stop transmission of ATM cells to the receiving side ATM unit for a certain period of time when it detects an AIS signal indicating a loss of service on the transmission side. The receiving side ATM unit is configured to monitor the reception of the ATM cells transmitted from the transmission side ATM unit and when it recognizes that the receiving of the ATM cells is stopped for a certain period of time, it generates an AIS signal indicating the loss of service on the transmission side and sends it on the communication line on the receiving side.

AIS transmission method in ATM communication system, transmission side

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Kawasaki, Japan

Mikio Nakayama